2024年4月3日发(作者：童白竹)
19-0273; Rev 7; 1/07
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
MAX3222/MAX3232/MAX3237/MAX3241
___________________________________概述
MAX3222/MAX3232/MAX3237/MAX3241收发器采用专有的
低压差发送器输出级，利用双电荷泵在3.0V至5.5V电源供
电时能够实现真正的RS-232性能。器件仅需四个0.1µF的外
部小尺寸电荷泵电容。MAX3222、MAX3232和MAX3241确
保在120kbps数据速率下维持RS-232输出电平。MAX3237在
正常工作模式下可确保250kbps的数据速率，MegaBaud
TM
工
作模式下保证1Mbps的速率，同时保持RS-232输出电平。
MAX3222/MAX3232具有2路接收器和2路驱动器。MAX3222
提供1µA关断模式，有效降低功耗并延长便携式产品的电
池使用寿命。关断模式下，接收器保持有效状态，对外
部设备(例如调制解调器)进行监测，仅消耗1µA电源电流。
MAX3222和MAX3232的引脚、封装和功能分别与工业标
准的MAX242和MAX232兼容。
MAX3241提供一个完整串口(3路驱动器/5路接收器)，设计
用于笔记本电脑和亚笔记本电脑。MAX3237(5路驱动器/
3路接收器)可理想用于高速调制解调器。这两款器件都具
有关断模式，关断时所有接收器保持有效状态，仅消耗1µA
电源电流。接收器R1(MAX3237/MAX3241)和R2(MAX3241)
除标准输出外还提供附加输出。这些附加输出始终保持
有效，可以对调制解调器等外部设备进行监测，电路(可能
已完全撤除V
CC
电源)中无需正向偏置保护二极管。
MAX3222、MAX3232以及MAX3241采用节省空间的TSSOP
和SSOP封装。
_________________________下一代器件特性
♦更小封装的器件：
MAX3228E/MAX3229E：+2.5V至+5.5V、RS-232
收发器，采用UCSP
TM
封装
♦集成ESD保护的器件：
MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E：±15kV ESD保护、电流低至10nA、
3.0V至5.5V供电、速率高达1Mbps的真RS-232收
发器
♦低电压或数据电缆传输应用：
MAX3380E/MAX3381E：+2.35V至+5.5V、1µA、
2Tx/2Rx RS-232收发器，带有±15kV ESD保护的
I/O和逻辑引脚
_______________________________定购信息
PART
MAX3222CUP+
MAX3222CAP+
MAX3222CWN+
MAX3222CPN+
TEMP RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
20 TSSOP
20 SSOP
18 SO
18 Plastic Dip
PKG
CODE
U20+2
A20+1
W18+1
P18+5
+
表示无铅封装。
定购信息(续)在数据资料的最后给出。
___________________________________应用
_______________________________引脚配置
笔记本电脑、亚笔记本电脑与掌上电脑
TOP VIEW
高速调制解调器
+
EN
1
18
SHDN
电池供电设备
C1+
2
17
V
CC
手持式装置
V+
3
16
GND
外设
C1-
4
MAX3222
15
T1OUT
打印机
C2+
5
MAX3222
14
R1IN
C2-
6
13
R1OUT
V-
7
12
T1IN
T2OUT
8
11
T2IN
R2IN
9
10
R2OUT
DIP/SO
引脚配置(续)在数据资料的最后给出。
典型工作电路在数据资料的最后给出。
MegaBaud和UCSP是Maxim Integrated Products, Inc.的商标。
________________________________________________________________Maxim Integrated Products1
本文是英文数据资料的译文，文中可能存在翻译上的不准确或错误。如需进一步确认，请在您的设计中参考英文资料。
有关价格、供货及订购信息，请联络Maxim亚洲销售中心：10800 852 1249 (北中国区)，10800 152 1249 (南中国区)，
或访问Maxim的中文网站：。
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
M
A
X
3
2
2
2
/
M
A
X
3
2
3
2
/
M
A
X
3
2
3
7
/
M
A
X
3
2
4
1
ABSOLUTE MAXIMUM RATINGS
V
CC
...........................................................................-0.3V to +6V
V+ (Note 1)...............................................................-0.3V to +7V
V- (Note 1)................................................................+0.3V to -7V
V+ + V- (Note 1)...................................................................+13V
Input Voltages
T_IN, SHDN, EN...................................................-0.3V to +6V
.-0.3V to (V
CC
+ 0.3V)
±25V
Output Voltages
±13.2V
-0.3V to (V
CC
+ 0.3V)
Short-Circuit Duration
Continuous
Continuous Power Dissipation (T
A
= +70°C)
16-Pin TSSOP (derate 6.7mW/°C above +70°C).............533mW
16-Pin Narrow SO (derate 8.70mW/°C above +70°C)....696mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C)........762mW
16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)...842mW
18-Pin SO (derate 9.52mW/°C above +70°C)..............762mW
18-Pin Plastic DIP (derate 11.11mW/°C above +70°C)..889mW
20-Pin SSOP (derate 7.00mW/°C above +70°C).........559mW
20-Pin TSSOP (derate 8.0mW/°C above +70°C).............640mW
28-Pin TSSOP (derate 8.7mW/°C above +70°C).............696mW
28-Pin SSOP (derate 9.52mW/°C above +70°C).........762mW
28-Pin SO (derate 12.50mW/°C above +70°C).....................1W
Operating Temperature Ranges
MAX32_ _C_ _.....................................................0°C to +70°C
MAX32_ _E_ _ .................................................-40°C to +85°C
Storage -65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
Note 1:V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DC CHARACTERISTICS
V
CC
Power-Supply Current
Shutdown Supply Current
Input Logic Threshold Low
(Note 3)
Input Logic Threshold High
(Note 3)
Input Leakage Current
Output Leakage Current
Output Voltage Low
Output Voltage High
RECEIVER INPUTS
Input Voltage Range
Input Threshold Low
Input Threshold High
T
A
= +25°C
T
A
= +25°C
V
CC
= 5.0V
V
CC
= 3.3V
V
CC
= 5.0V
V
CC
= 3.3V
V
CC
= 5.0V
-25
0.6
0.8
1.2
1.5
1.5
1.8
2.4
2.4
25V
V
V
No load, V
CC
= 3.3V or 5.0V,
T
A
= +25°C
SHDN= GND, T
A
= +25°C
MAX3222/MAX3232/
MAX3241
MAX3237
0.3
0.5
1.0
1.0
2.0
10µA
mA
CONDITIONS
MINTYPMAX
UNITS
LOGIC INPUTS AND RECEIVER OUTPUTS
T_IN, EN, SHDN, MBAUD
V
CC
= 3.3V
V
CC
= 5.0V
T_IN, EN, SHDN, MBAUD
Receivers disabled
I
OUT
= 1.6mA
I
OUT
= -1.0mAV
CC
- 0.6V
CC
- 0.1
2.0
2.4
±0.01
±0.05
±1.0
±10
0.4
0.8V
V
µA
µA
V
V
2_______________________________________________________________________________________
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Input Hysteresis
Input Resistance
TRANSMITTER OUTPUTS
Output Voltage Swing
Output Resistance
Output Short-Circuit Current
Output Leakage Current
V
OUT
= ±12V, V
CC
= 0V or 3V to 5.5V, transmitters
disabled
All transmitter outputs loaded with 3kΩto ground
V
CC
= V+ = V- = 0V, V
OUT
= ±2V
±5.0
300
±5.4
10M
±35±60
±25
V
Ω
mA
µA
T
A
= +25°C3
CONDITIONS
MINTYP
0.3
57
MAX
UNITS
V
kΩ
MAX3222/MAX3232/MAX3237/MAX3241
MOUSE DRIVEABILITY (MAX3241)
Transmitter Output Voltage
T1IN = T2IN = GND, T3IN = V
CC
,
T3OUT loaded with 3kΩto GND,
T1OUT and T2OUT loaded with 2.5mA each
±5.0V
TIMING CHARACTERISTICS—MAX3222/MAX3232/MAX3241
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Maximum Data Rate
Receiver Propagation Delay
Receiver Output Enable Time
Transmitter Skew
CONDITIONS
R
L
= 3kΩ, C
L
= 1000pF, one transmitter switching
R_IN to R_OUT, C
L
= 150pF
Normal operation
t
PHL
t
PLH
MIN
120
TYP
235
0.3
0.3
200
200
300
MAX
UNITS
kbps
µs
ns
ns
ns
Receiver Output Disable TimeNormal operation
|
t
PHL
- t
PLH
|
Receiver Skew
|
t
PHL
- t
PLH
|
300ns
V
CC
= 3.3V, R
L
= 3kΩto 7kΩ,
C
L
= 150pF to
Transition-Region Slew Rate
+3V to -3V or -3V to +3V,
1000pF
630
T
A
= +25°C, one transmitter
switching
C
V/µs
L
= 150pF to
2500pF
430
_______________________________________________________________________________________3
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
M
A
X
3
2
2
2
/
M
A
X
3
2
3
2
/
M
A
X
3
2
3
7
/
M
A
X
3
2
4
1
TIMING CHARACTERISTICS—MAX3237
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETERCONDITIONS
R
L
= 3kΩ, C
L
= 1000pF, one transmitter switching,
MBAUD = GND
Maximum Data Rate
V
CC
= 3.0V to 4.5V, R
L
= 3kΩ, C
L
= 250pF,
one transmitter switching, MBAUD = V
CC
V
CC
= 4.5V to 5.5V, R
L
= 3kΩ, C
L
= 1000pF,
one transmitter switching, MBAUD = V
CC
Receiver Propagation Delay
Receiver Output Enable Time
R_IN to R_OUT, C
L
= 150pF
Normal operation
t
PHL
t
PLH
MIN
250
1000
1000
0.15
0.15
200
200
100
25
50
C
L
= 150pF
to 1000pF
MBAUD =
GND
MBAUD =
V
CC
6
24
4
30
150
30
V/µs
µs
ns
ns
ns
ns
ns
kbps
TYPMAX
UNITS
Receiver Output Disable TimeNormal operation
Transmitter Skew
Receiver Skew
|
t
PHL
- t
PLH
|
, MBAUD = GND
|
t
PHL
- t
PLH
|
, MBAUD = V
CC
|
t
PHL
- t
PLH
|
Transition-Region Slew Rate
V
CC
= 3.3V, R
L
= 3Ωto 7kΩ,
+3V to -3V or -3V to +3V,
T
A
= +25°C
C
L
= 150pF to 2500pF,
MBAUD = GND
Note 2:MAX3222/MAX3232/MAX3241: C1–C4 = 0.1µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested at 5.0V ±10%.
MAX3237: C1–C4 = 0.1µF tested at 3.3V ±5%; C1–C4 = 0.22µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested
at 5.0V ±10%.
Note 3:Transmitter input hysteresis is typically 250mV.
_________________________________________________________________________典型工作特性
(V
CC
= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, T
A
= +25°C, unless otherwise noted.)
MAX3222/MAX3232
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
M
A
X
3
2
2
2
-
0
1
MAX3222/MAX3232
SLEW RATE
vs. LOAD CAPACITANCE
20
18
S
L
E
W
R
A
T
E
(
V
/
µ
s
)
16
14
12
10
8
6
4
2
0
5000
150
10005000
+SLEW
-SLEW
FOR DATA RATES UP TO 235kbps
M
A
X
3
2
2
2
-
0
2
MAX3222/MAX3232
SUPPLY CURRENT vs. LOAD CAPACITANCE
WHEN TRANSMITTING DATA
35
S
U
P
P
L
Y
C
U
R
R
E
N
T
(
m
A
)
30
25
120kbps
20
15
20kbps
10
5
0
0
10005000
M
A
X
3
2
2
2
-
0
3
T
R
A
N
S
M
I
T
T
E
R
O
U
T
P
U
T
V
O
L
T
A
G
E
(
V
)
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
0
1
22
40
235kbps
V
OUT
+
V
OUT
-
4000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
4_______________________________________________________________________________________
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
____________________________________________________________________典型工作特性(续)
(V
CC
= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, T
A
= +25°C, unless otherwise noted.)
MAX3241
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
M
A
X
3
2
2
2
-
0
4
MAX3222/MAX3232/MAX3237/MAX3241
MAX3241
SLEW RATE
vs. LOAD CAPACITANCE
M
A
X
3
2
2
2
-
0
5
MAX3241
SUPPLY CURRENT vs. LOAD
CAPACITANCE WHEN TRANSMITTING DATA
40
S
U
P
P
L
Y
C
U
R
R
E
N
T
(
m
A
)
35
30
25
20
15
10
5
0
5000
0
10005000
LOAD CAPACITANCE (pF)
20kbps
120kbps
235kbps
M
A
X
3
2
2
2
-
0
6
7.5
T
R
A
N
S
M
I
T
T
E
R
O
U
T
P
U
T
V
O
L
T
A
G
E
(
V
)
V
OUT
+
5.0
2.5
0
-2.5
-5.0
-7.5
0
1000
V
OUT
-
24
22
20
S
L
E
W
R
A
T
E
(
V
/
µ
s
)
18
16
14
12
10
8
6
4
+SLEW
ALL OUTPUTS LOADED WITH 3kΩ +C
L
0.1µF CHARGE-PUMP CAPACITORS
FOR ALL DATA RATES UP TO 235kbps
0
1000
LOAD CAPACITANCE (pF)
45
1 TRANSMITTER AT 235kbps
2 TRANSMITTERS AT 30kbps
-SLEW
5000
LOAD CAPACITANCE (pF)
MAX3237
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = GND)
M
A
X
3
2
2
2
-
0
7
MAX3237
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = V
CC
)
R
A
N
S
M
I
T
T
E
R
O
U
T
P
U
T
V
O
L
T
A
G
E
(
V
)
1Mbps
5.0
2.5
0
-2.5
-5.0
2Mbps
1.5Mbps
2
2Mbps
1.5Mbps
M
A
X
3
2
2
2
-
0
8
MAX3237
SLEW RATE vs. LOAD CAPACITANCE
(MBAUD = GND)
M
A
X
3
2
2
2
-
0
9
7.5
R
A
N
S
M
I
T
T
E
R
O
U
T
P
U
T
V
O
L
T
A
G
E
(
V
)
5.0
2.5
0
-2.5
-5.0
7.5
12
10
S
L
E
W
R
A
T
E
(
V
/
µ
s
)
8
6
4
1 TRANSMITTER AT 240kbps
4 TRANSMITTERS AT 15kbps
3kΩ + C
L
LOADS
+SLEW
-SLEW
1 TRANSMITTER AT 240kbps
4 TRANSMITTERS AT 15kbps
3kΩ + C
L
LOADS
V
CC
= 3.3V
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
3kΩ + C
L
LOAD, EACH OUTPUT
V
CC
= 3.3V
T
T
1Mbps
V
CC
= 3.3V
-7.5
-7.5
0
0
10005000
0
500
0
10005000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
MAX3237
MAX3237
MAX3237
SLEW RATE vs. LOAD CAPACITANCE
SUPPLY CURRENT vs.
SKEW vs. LOAD CAPACITANCE
(MBAUD = V
CC
)
LOAD CAPACITANCE (MBAUD = GND)
(t
PLH
- t
PHL
)
70
0
60
1
1
1
70
2
-
-
2
2
1
-
2
2
2
2
)
3
3
X
X
1 TRANSMITTER AT 512kbps
2
s
2
2
A
A
M
M
60
n
4 TRANSMITTERS AT 32kbps
3
X
60
(
A
M
-SLEW, 1Mbps
50
W
)
240kbps
A
E
3kΩ + C
K
)
s
50
+SLEW, 1Mbps
m
(
50
S
V
= 3.3V
L
LOADS
µ
MBAUD = V
CC
CC
/
T
40
120kbps
V
-SLEW, 2Mbps
N
(
E
E
+SLEW, 2Mbps
R
T
40
40
MAX
A
R
R
U
30
C
AVERAGE; 10 PARTS
W
30
Y
20kbps
30
E
L
L
P
S
P
20
20
U
1 TRANSMITTER AT FULL DATA RATE
S
1 TRANSMITTER AT FULL DATA RATE
20
10
4 TRANSMITTERS AT 1/16 DATA RATE
3kΩ + C
10
4 TRANSMITTERS AT 1/16 DATA RATE
L
LOAD EACH OUTPUT
3kΩ + C
L
LOADS
10
V
MIN
CC
= 3.3V
0
V
CC
= 3.3V
0
0
500
0
10005000
0
0
5002500
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
_______________________________________________________________________________________5
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
M
A
X
3
2
2
2
/
M
A
X
3
2
3
2
/
M
A
X
3
2
3
7
/
M
A
X
3
2
4
1
__________________________________________________________________________引脚说明
引脚
MAX3222
DIP/SO
1
2
3
4
5
6
7
8, 15
9, 14
10, 13
11, 12
16
17
18
—
—
—
SSOP
1
2
3
4
5
6
7
8, 17
9, 16
10, 15
12, 13
18
19
20
11, 14
—
—
MAX3232
—
1
2
3
4
5
6
7, 14
8, 13
9, 12
10, 11
15
16
—
—
—
—
MAX3237
13
28
27
25
1
3
4
5, 6, 7,
10, 12
8, 9, 11
18, 20, 21
17, 19, 22,
23, 24
2
26
14
—
15
16
MAX3241
23
28
27
24
1
2
3
9, 10, 11
4–8
15–19
12, 13, 14
25
26
22
—
—
20, 21
名称功能
EN
C1+
V+
C1-
C2+
C2-
V-
T_OUT
R_IN
R_OUT
T_IN
GND
V
CC
SHDN
N.C.
MBAUD
R_OUTB
接收器使能，低电平有效。
倍压电荷泵电容的正端。
电荷泵产生的+5.5V。
倍压电荷泵电容的负端。
反相电荷泵电容的正端。
反相电荷泵电容的负端。
电荷泵产生的-5.5V。
RS-232发送器输出。
RS-232接收器输入。
TTL/CMOS接收器输出。
TTL/CMOS发送器输入。
地。
+3.0V至+5.5V供电电源。
关断控制，低电平有效。
没有连接。
MegaBaud控制输入。连接至GND时，工作在常规速率；
连接至V
CC
时传输速率达1Mbps。
同相互补接收器输出，始终保持有效。
6_______________________________________________________________________________________
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
_______________________________详细说明
双电荷泵电压转换器
MAX3222/MAX3232/MAX3237/MAX3241的内部电源由两路
稳压型电荷泵组成，只要输入电压(V
CC
)在3.0V至5.5V范围
以内，即可提供+5.5V(倍压电荷泵)和-5.5V(反相电荷泵)
输出电压。电荷泵工作在非连续模式，一旦输出电压低于
5.5V，将开启电荷泵；输出电压超过5.5V时，即刻关闭电
荷泵。每个电荷泵需要一个飞电容(C1、C2)和一个储能电
容(C3、C4)，产生V+和V-电压。
器件处于关断模式时，MAX3222/MAX3237/MAX3241输
出级关断(置为高阻)。关闭电源时，MAX3222/MAX3232/
MAX3237/MAX3241允许输出端驱动至最高±12V。
发送器输入没有上拉电阻，将未使用的输入连接至GND或
V
CC
。
MAX3222/MAX3232/MAX3237/MAX3241
MAX3237 MegaBaud工作模式
常规工作模式(MBAUD=GND)下，MAX3237发送器能够在
最差工作条件(3kΩ电阻与1000pF电容的并联负载)下保证
250kbps的数据速率，提供PC至PC通信软件(例如LapLink)
的兼容性。
为了获得更高的串行通信速率，MAX3237提供MegaBaud工
作模式。在MegaBaud工作模式(MBAUD=V
CC
)下，MAX3237
发送器能够在最差工作条件(3kΩ电阻与250pF电容的并联负
载，3.0V CC <4.5V)下保证1Mbps的数据速率。5V±10% 供电时，MAX3237发送器能够在最差工作条件(3kΩ电阻与 1000pF电容的并联负载)下保证1Mbps的数据速率。 RS-232发送器 发送器为反相电平转换器，将CMOS逻辑电平转换成5.0V EIA/TIA-232电平。 MAX3222/MAX3232/MAX3241在最差工作条件(3kΩ电阻与 1000pF电容的并联负载)下能够保证120kbps的数据速率， 提供PC至PC通信软件(例如LapLink TM )兼容性。通常情况下， 这三款器件能够工作于235kbps数据速率。发送器可并联驱 动多个接收器或鼠标。 LapLink是Traveling Software, Inc.的商标。 * MAX3222/MAX3237/MAX3241 ONLY 图1. 摆率测试电路 _______________________________________________________________________________________7 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 M A X 3 2 2 2 / M A X 3 2 3 2 / M A X 3 2 3 7 / M A X 3 2 4 1 RS-232接收器 V CC 接收器将RS-232信号转换成CMOS逻辑输出电平，MAX3222/ MAX3237/MAX3241接收器提供反相三态输出。关断模式 下，接收器可处于有效或无效状态(表1)。 PREVIOUS RS-232 V CC Rx PROTECTION DIODE UART Tx GND SHDN = GND MAX3237(R1OUTB)和MAX3241(R1OUTB、R2OUTB)互补 输出始终保持有效，与 EN 或 SHDN 状态无关。这些器件适 用于振铃指示器等应用，不需要正向偏置连接到接收器输 出端的其它器件。该功能可理想用于在关断模式下将V CC 置为0V以适应外设操作(例如UART)的系统(图2)。 5kΩ MAX3222/MAX3237/MAX3241关断模式 关断模式( SHDN =低电平)下，电源电流降至1µA以内。关 断时，器件的电荷泵关闭，V+下拉至V CC ，V-拉至地电位， 发送器输出被禁止(高阻)。退出关断模式的时间通常为100µs， 如图3所示。如果不使用关断模式，则将 SHDN 连接至V CC 。 SHDN 不影响R_OUT或R_OUTB。 a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM ACTIVE RECEIVER OUTPUT IN SHUTDOWN. MAX3222/MAX3237/MAX3241使能控制 当 EN 为高电平时，反相接收器输出(R_OUT)置为高阻态。 互补输出R1OUTB和R2OUTB始终保持有效，与 EN 和 SHDN 的状态无关(表1)， EN 不影响T_OUT。 V CC TO µP LOGIC TRANSITION DETECTOR _______________________________应用信息 注意！！！！！ MAX3237 MAX3241 R1OUTB 电容选择 C1至C4所使用的电容类型对于正常工作影响不大，可以使 用有极性或无极性电容。3.3V供电时，电荷泵需要0.1µF 电容；其它供电电压下的电容选择请参考表2，不要使用 低于表2所列容值的电容。增大电容值(例如增大2倍)有助 于降低发送器输出的纹波，并对降低功耗略有帮助。可以 不改变C1，只是增大C2、C3和C4。但是，请勿在C2、C3 和C4没有增大的情况下增大C1，需维持这些电容之间的适 当比值(C1相对于其它电容)。 如果使用了所要求的最小电容，请确保电容值不会随着温 度的变化而出现明显的下降。如果不能确保这一条件，请 使用具有较高标称值的电容。电容等效串联电阻(ESR)通常 在低温下增大，它会影响V+和V-的纹波。 V CC Rx PROTECTION DIODE UART Tx GND T1IN SHDN = GND R1OUT EN = V CC 5kΩ T1OUT R1IN b) NEW MAX3237/MAX3241: EN SHUTS DOWN RECEIVER OUTPUTS (EXCEPT FOR B OUTPUTS), SO NO CURRENT FLOWS TO UART IN SHUTDOWN. B OUTPUTS INDICATE RECEIVER ACTIVITY DURING SHUTDOWN WITH EN HIGH. 图2. 当UART和接口关断时，RS-232的有效检测；MAX3237/ MAX3241 (b)与早期收发器(a)的比较 8_______________________________________________________________________________________ 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 表1. MAX3222/MAX3237/MAX3241关断和 使能控制真值表 SHDN 0 0 1 1 EN 0 1 0 1 T_OUT High-Z High-Z Active Active R_OUT Active High-Z Active High-Z R_OUTB (MAX3237/ MAX3241) Active Active Active Active 电源去耦 大多数情况下，使用一个0.1µF旁路电容即可满足要求。 在对电源噪声敏感的应用中，采用与电荷泵电容C1相同 的电容将V CC 旁路到地，进行去耦。旁路电容应尽量靠近 IC放置。 MAX3222/MAX3232/MAX3237/MAX3241 工作在最低2.7V 当电源电压低至2.7V时，发送器输出仍可满足EIA/TIA- 562要求的±3.7V电平。 退出关断模式时发送器的输出 表2. 所要求的最小电容值 V CC (V) C1 (µF) C2, C3, C4 (µF) MAX3222/MAX3232/MAX3241 3.0 to 3.6 4.5 to 5.5 3.0 to 5.5 MAX3237 3.0 to 3.6 3.15 to 3.6 4.5 to 5.5 3.0 to 5.5 0.22 0.1 0.047 0.22 0.22 0.1 0.33 1.0 0.1 0.047 0.1 0.1 0.33 0.47 图3所示为退出关断模式时的两路发送器输出。当两路发 送器输出有效时，发送器输出与RS-232电平反相的信号 (一路发送器输入为高电平，另一路为低电平)。每个发送 器负载为3kΩ电阻并联2500pF电容。退出关断模式时，发 送器输出显示没有振铃，也不存在所不希望的瞬变电压。 注意，只有在V-幅值超过3V左右时，才会使能发送器。 鼠标驱动能力 MAX3241设计用于串口鼠标驱动，能够工作在较低的电源 电压。该器件经过一些重要的鼠标生产厂家的测试，例如 Microsoft和Logitech。MAX3241能够成功驱动所有测试的串 口鼠标，满足相应的电流、电压要求。图4a所示为3.0V供 电时，发送器输出电压随负载电流的变化情况；图4b所示 为使用MAX3241时典型的鼠标连接。 5V/div T2 2V/div T1 50µs/div V CC = 3.3V C1–C4 = 0.1µF 图3. 退出关断模式或上电时发送器的输出 _______________________________________________________________________________________9 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 M A X 3 2 2 2 / M A X 3 2 3 2 / M A X 3 2 3 7 / M A X 3 2 4 1 T R A N S M I T T E R O U T P U T V O L T A G E ( V ) 4 3 2 1 0 -1 -2 -3 -4 -5 -6 01234567 LOAD CURRENT PER TRANSMITTER (mA) V CC V CC = 3.0V T1 V OUT + V OUT + T2 T3 V OUT - V OUT - 图4a. MAX3241每路发送器输出电压与负载电流之间的关系 V CC = 3V to 5.5V 0.1µF 26 V CC 27 C3 COMPUTER SERIAL PORT 3 C4 9 +V 10 11 +V -V GND R1IN4 5kΩ 5kΩ! 5kΩ! 5kΩ! 5kΩ! GND 25 SHDN R2IN5 R3IN 6 R4IN 7 MOUSE R5IN8 22 Tx 28 C 1 24 1 C 2 2 14 13 V CC 12 21 20 19 18 17 16 15 23 C1+ C1- C2+ C2- T1IN T2IN T3IN R1OUTB R2OUTB R1OUT R2OUT R3OUT R4OUT R5OUT EN V+ MAX3241 V- T1OUT T2OUT T3OUT 图4b. 鼠标驱动测试电路 10______________________________________________________________________________________ M A X 3 2 2 2 - 0 4 6 5 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 MAX3222/MAX3232/MAX3237/MAX3241 V CC 0.1µF V CC V+ C3 C1- C2+ C2 C2- R1OUT 5V/div T1IN 5V/div C1+ C1 T1OUT 5V/div MAX3222 MAX3232 MAX3237 MAX3241 V- C4 5µs/div V CC = 3.3V T_ IN T_ OUT 图6. MAX3241在120kbps数据速率下的环回测试结果 R_ OUT 0V V CC EN * R_ IN 5kΩ 1000pF T1IN 5V/div SHDN * GND T1OUT 5V/div * MAX3222/MAX3237/MAX3241 ONLY R1OUT 5V/div 图5. 环回测试电路 V CC = 3.3V 2µs/div 高数据速率 图7. MAX3241在235kbps数据速率下的环回测试结果 即使工作在高数据速率下，MAX3222/MAX3232/MAX3241 仍然能够保持RS-232标准要求的±5.0V最小发送器输出电 压。图5所示为发送器环回测试电路，图6所示为120kbps +5V 数据速率下的环回测试结果，图7所示为235kbps数据速率 0V T_IN 下的相同测试。图6中，所有发送器同时以120kbps的数据 +5V 速率驱动并联了1000pF电容的RS-232负载。图7中，单个 发送器工作在235kbps数据速率，所有发送器的负载都是 0V T_OUT = R_IN 并联了1000pF电容的RS-232接收器。 -5V 5kΩ + 250pF MAX3237在高达1Mbps的数据速率下能够保持RS-232标准 +5V 要求的±5.0V最小发送器输出电压。图8所示为1Mbps下， 0V R_OUT 150pF MBAUD = V CC 时电路的环回测试结果。对于图8，所有发 送器负载为并联了250pF电容的RS-232接收器。 V 200ns/div CC = 3.3V 图8. MAX3237在1000kbps (MBAUD = V CC )数据速率下的环回测试 结果 ______________________________________________________________________________________11 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 M A X 3 2 2 2 / M A X 3 2 3 2 / M A X 3 2 3 7 / M A X 3 2 4 1 与3V和5V逻辑电平互联 MAX3222/MAX3232/MAX3237/MAX3241可直接与各种5V 逻辑电平接口，包括ACT和HCT CMOS。表3列出了各种 可能的互联组合的详细信息。 表3. 不同电源电压下的逻辑电平兼容性 SYSTEM POWER- SUPPLY VOLTAGE (V) 3.3 5 MAX32_ _ V CC SUPPLY VOLTAGE (V) 3.3 5 COMPATIBILITY Compatible with all CMOS families. Compatible with all TTL and CMOS-logic families. Compatible with ACT and HCT CMOS, and with TTL. Incompatible with AC, HC, and CD4000 CMOS. 53.3 ______________________________________________________________________典型工作电路 +3.3V 0.1µF C1 0.1µF 2 C1+ 4 5 C2 0.1µF 6 C1- C2+ C2- T1OUT 15 RS-232 OUTPUTS 11 T2IN T2OUT 8 TTL/CMOS INPUTS 10 T2IN T2OUT 7 17 V CC V+ 3 C3 * 0.1µF 7 C4 0.1µF 0.1µF 0.1µF +3.3V 0.1µF 1 C1+ 3 4 5 C1- C2+ C2- T1OUT 14 RS-232 OUTPUTS 16 V CC V+ 2 C3 * 0.1µF 6 C4 0.1µF MAX3222 V- MAX3232 V- 12 T1IN TTL/CMOS INPUTS 11 T1IN 13R1OUT TTL/CMOS OUTPUTS 10R2OUT 1 EN GND 16 R1IN 14 5kΩ R2IN 9 5kΩ SHDN 18 RS-232 INPUTS TTL/CMOS OUTPUTS 12R1OUT R1IN 13 5kΩ RS-232 INPUTS 9R2OUT R2IN 8 5kΩ GND 15 PIN NUMBERS REFER TO DIP/SO PACKAGES. * C3 CAN BE RETURNED TO EITHER V CC OR GROUND. SEE TABLE 2 FOR CAPACITOR SELECTION * C3 CAN BE RETURNED TO EITHER V CC OR GROUND. 12______________________________________________________________________________________ 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 ___________________________________________________________________典型工作电路(续) MAX3222/MAX3232/MAX3237/MAX3241 0.1µF 26 28 C1+ 25 C1- 1 0.1µF 3 C2+ C2- T1 T2 T3 T4 T5 T1OUT5 T2OUT6 T3OUT 7 T4OUT10 20 R2OUTB T5OUT 12 19 R1OUT R1IN 4 5kΩ R1IN 8 5kΩ 20 R2OUT R2IN9 RS-232 TTL/CMOS OUTPUTS 18 R2OUT R2IN 5kΩ 17 R3OUT R3IN 6 RS-232 5 RS-232 OUTPUTS V CC V+ 27 0.1µF 4 0.1µF 0.1µF +3.3V 0.1µF 0.1µF 28 C1+ 24 C1- 26 V CC V+ 27 C3 * 0.1µF 3 C4 0.1µF 0.1µF MAX3237 V- 1 2 C2+ C2- MAX3241 V- 24 T1IN 23 T2IN LOGIC INPUTS 22 T3IN 19 T4IN 17 T5IN 16 R1OUTB 14 T1IN 13 T2IN 12 T3IN 21 R1OUTB T1OUT9 T2OUT10 T3OUT 11 TTL/CMOS INPUTS RS-232 OUTPUTS 21 R1OUT R1 LOGIC R2 OUTPUTS INPUTS INPUTS 5kΩ 5kΩ 18 R3OUT 16 R4OUT R4IN 7 R3 R3IN 11 5kΩ 5kΩ 15 R5OUT R5IN8 MBAUD 15 5kΩ 13 EN 14 23 EN GND SHDN GND SHDN 22 2 25 * C3 CAN BE RETURNED TO EITHER V CC OR GROUND. * C3 CAN BE RETURNED TO EITHER V CC OR GROUND. ______________________________________________________________________________________13 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 M A X 3 2 2 2 / M A X 3 2 3 2 / M A X 3 2 3 7 / M A X 3 2 4 1 _______________________________________________________________________引脚配置(续) TOP VIEW + EN 1 C1+ 2 V+ 3 C1- 4 C2+ 5 C2- 6 V- 7 T2OUT 8 R2IN 9 R2OUT 10 20 SHDN 19 V CC 18 GND 17 T1OUT C1+ 1 V+ 2 C1- 3 C2+ 4 C2- 5 V- 6 T2OUT 7 R2IN 8 + 16 V CC 15 GND 14 T1OUT MAX3222 16 R1IN 15 R1OUT 14 N.C. 13 T1IN 12 T2IN 11 N.C. MAX3232 13 R1IN 12 R1OUT 11 T1IN 10 T2IN 9 R2OUT DIP/SO/SSOP/TSSOP SSOP/TSSOP + C2+ GND C2- V- T1OUT T2OUT T3OUT R1IN R2IN 1 2 3 4 5 6 7 8 9 + 28 C1+ 27 V+ 26 V CC 25 C1- C2+ C2- V- R1IN R2IN R3IN R4IN R5IN T1OUT 1 2 3 4 5 6 7 8 9 28 C1+ 27 V+ 26 V CC 25 GND MAX3237 24 T1IN 23 T2IN 22 T3IN 21 R1OUT 20 R2OUT 19 T4IN 18 R3OUT 17 T5IN 16 R1OUTB 15 MBAUD MAX3241 24 C1- 23 EN 22 SHDN 21 R1OUTB 20 R2OUTB 19 R1OUT 18 R2OUT 17 R3OUT 16 R4OUT 15 R5OUT T4OUT 10 R3IN 11 T5OUT 12 EN 13 SHDN 14 T2OUT 10 T3OUT 11 T3IN 12 T2IN 13 T1IN 14 SSOP SO/SSOP/TSSOP 14______________________________________________________________________________________ 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 _______________________________________________________________________定购信息(续) PART MAX3222EUP+ MAX3222EAP+ MAX3222EWN+ MAX3222EPN+ MAX3222C/D MAX3232CUE+ MAX3232CSE+ MAX3232CWE+ MAX3232CPE+ MAX3232EUE+ MAX3232ESE+ TEMP RANGE -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C 0°C to +70°C 0°C to +70°C 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C PIN-PACKAGE 20 TSSOP 20 SSOP 18 SO 18 Plastic Dip Dice* 16 TSSOP 16 Narrow SO 16 Wide SO 16 Plastic DIP 16 TSSOP 16 Narrow SO PKG CODE U20+2 A20+1 W18+1 P18+5 — U16+1 S16+1 W16+1 P16+1 U16+1 S16+5 PART MAX3232EWE+ MAX3232EPE+ MAX3232CAE+ MAX3237CAI+ MAX3237EAI+ MAX3241CAI+ MAX3241CWI+ MAX3241EUI+ MAX3241EAI+ MAX3241EWI+ TEMP RANGE -40°C to +85°C -40°C to +85°C 0°C to +70°C 0°C to +70°C -40°C to +85°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -40°C to +85°C PIN-PACKAGE 16 Wide SO 16 Plastic DIP 16 SSOP 28 SSOP 28 SSOP 28 SSOP 28 SO 28 TSSOP 28 SSOP 28 SO PKG CODE W16+1 P16+1 A28+2 A28+1 A28+1 A28+1 W28+6 U28+2 A28+1 W28+6 MAX3222/MAX3232/MAX3237/MAX3241 * 裸片在T A = +25 ° C下经过测试，仅限直流参数。 + 表示无铅封装。 __________________________________Maxim提供的3V供电EIA/TIA-232和EIA/TIA-562收发器 POWER- SUPPLY VOLTAGE (V) 3.0 to 3.6 1.8 to 4.25 2.7 to 5.25 3.0 to 3.6 No. OF TRANSMITTERS/ RECEIVERS 3/5 2/2 3/5 2/2 No. OF RECEIVERS ACTIVE IN SHUTDOWN 5 2 5 2 GUAR- ANTEED DATA RATE (kbps) 120 120 230 230 EIA/ TIA-232 OR 562 232 232 562 562 PARTFEATURES MAX212 MAX218 MAX562 MAX563 Drives mice Operates directly from batteries without a voltage regulator Wide supply range 0.1µF capacitors AutoShutdown, complementary MAX32122.7 to 3.63/55235232receiver, drives mice, transient detection MAX32223.0 to 5.52/221202320.1µF capacitors MAX32233.0 to 5.52/221202320.1µF capacitors, AutoShutdown MAX32323.0 to 5.52/2N/A1202320.1µF capacitors 0.1µF capacitors, 1 complemen- MAX32373.0 to 5.55/33250/1000232tary receiver, MegaBaud operation MAX32413.0 to 5.53/55120232 0.1µF capacitors, 2 complemen- tary receivers, drives mice 0.1µF capacitors, AutoShutdown, MAX32433.0 to 5.53/51120232complementary receiver, drives mice ______________________________________________________________________________________15 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 M A X 3 2 2 2 / M A X 3 2 3 2 / M A X 3 2 3 7 / M A X 3 2 4 1 _______________________________芯片拓扑 MAX3222 V+C1+EN SHDN V CC _______________________________芯片信息 PART MAX3222 TRANSISTOR COUNT 339 339 1212 894 GND C1- C2+ T1OUT 0.127" (3.225mm) C2- MAX3232 MAX3237 MAX3241 R1IN V- R1OUT T2OUTR2INR2OUT 0.087" (2.209mm) T2INT1IN TRANSISTOR COUNT: 339 SUBSTRATE CONNECTED TO GND 16______________________________________________________________________________________ 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 _____________________________________________________________________________ 封装信息 如需最近的封装外形信息和焊盘布局，请查询/packages。 MAX3222/MAX3232/MAX3237/MAX3241 T S S O P 4 . 4 0 m m . E P S _______________________________修订历史 Rev 7中的修改页：1、15、16、17 Maxim不对Maxim产品以外的任何电路使用负责，也不提供其专利许可。Maxim保留在任何时间、没有任何通报的前提下修改产品资料和规格的权利。 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ______________________17 ©2007 Maxim Integrated Products Maxim 是 Maxim Integrated Products, Inc. 的注册商标。 Narrow SO 窄体SO封装
2024年4月3日发(作者：童白竹)
19-0273; Rev 7; 1/07
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
MAX3222/MAX3232/MAX3237/MAX3241
___________________________________概述
MAX3222/MAX3232/MAX3237/MAX3241收发器采用专有的
低压差发送器输出级，利用双电荷泵在3.0V至5.5V电源供
电时能够实现真正的RS-232性能。器件仅需四个0.1µF的外
部小尺寸电荷泵电容。MAX3222、MAX3232和MAX3241确
保在120kbps数据速率下维持RS-232输出电平。MAX3237在
正常工作模式下可确保250kbps的数据速率，MegaBaud
TM
工
作模式下保证1Mbps的速率，同时保持RS-232输出电平。
MAX3222/MAX3232具有2路接收器和2路驱动器。MAX3222
提供1µA关断模式，有效降低功耗并延长便携式产品的电
池使用寿命。关断模式下，接收器保持有效状态，对外
部设备(例如调制解调器)进行监测，仅消耗1µA电源电流。
MAX3222和MAX3232的引脚、封装和功能分别与工业标
准的MAX242和MAX232兼容。
MAX3241提供一个完整串口(3路驱动器/5路接收器)，设计
用于笔记本电脑和亚笔记本电脑。MAX3237(5路驱动器/
3路接收器)可理想用于高速调制解调器。这两款器件都具
有关断模式，关断时所有接收器保持有效状态，仅消耗1µA
电源电流。接收器R1(MAX3237/MAX3241)和R2(MAX3241)
除标准输出外还提供附加输出。这些附加输出始终保持
有效，可以对调制解调器等外部设备进行监测，电路(可能
已完全撤除V
CC
电源)中无需正向偏置保护二极管。
MAX3222、MAX3232以及MAX3241采用节省空间的TSSOP
和SSOP封装。
_________________________下一代器件特性
♦更小封装的器件：
MAX3228E/MAX3229E：+2.5V至+5.5V、RS-232
收发器，采用UCSP
TM
封装
♦集成ESD保护的器件：
MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E：±15kV ESD保护、电流低至10nA、
3.0V至5.5V供电、速率高达1Mbps的真RS-232收
发器
♦低电压或数据电缆传输应用：
MAX3380E/MAX3381E：+2.35V至+5.5V、1µA、
2Tx/2Rx RS-232收发器，带有±15kV ESD保护的
I/O和逻辑引脚
_______________________________定购信息
PART
MAX3222CUP+
MAX3222CAP+
MAX3222CWN+
MAX3222CPN+
TEMP RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
20 TSSOP
20 SSOP
18 SO
18 Plastic Dip
PKG
CODE
U20+2
A20+1
W18+1
P18+5
+
表示无铅封装。
定购信息(续)在数据资料的最后给出。
___________________________________应用
_______________________________引脚配置
笔记本电脑、亚笔记本电脑与掌上电脑
TOP VIEW
高速调制解调器
+
EN
1
18
SHDN
电池供电设备
C1+
2
17
V
CC
手持式装置
V+
3
16
GND
外设
C1-
4
MAX3222
15
T1OUT
打印机
C2+
5
MAX3222
14
R1IN
C2-
6
13
R1OUT
V-
7
12
T1IN
T2OUT
8
11
T2IN
R2IN
9
10
R2OUT
DIP/SO
引脚配置(续)在数据资料的最后给出。
典型工作电路在数据资料的最后给出。
MegaBaud和UCSP是Maxim Integrated Products, Inc.的商标。
________________________________________________________________Maxim Integrated Products1
本文是英文数据资料的译文，文中可能存在翻译上的不准确或错误。如需进一步确认，请在您的设计中参考英文资料。
有关价格、供货及订购信息，请联络Maxim亚洲销售中心：10800 852 1249 (北中国区)，10800 152 1249 (南中国区)，
或访问Maxim的中文网站：。
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
M
A
X
3
2
2
2
/
M
A
X
3
2
3
2
/
M
A
X
3
2
3
7
/
M
A
X
3
2
4
1
ABSOLUTE MAXIMUM RATINGS
V
CC
...........................................................................-0.3V to +6V
V+ (Note 1)...............................................................-0.3V to +7V
V- (Note 1)................................................................+0.3V to -7V
V+ + V- (Note 1)...................................................................+13V
Input Voltages
T_IN, SHDN, EN...................................................-0.3V to +6V
.-0.3V to (V
CC
+ 0.3V)
±25V
Output Voltages
±13.2V
-0.3V to (V
CC
+ 0.3V)
Short-Circuit Duration
Continuous
Continuous Power Dissipation (T
A
= +70°C)
16-Pin TSSOP (derate 6.7mW/°C above +70°C).............533mW
16-Pin Narrow SO (derate 8.70mW/°C above +70°C)....696mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C)........762mW
16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)...842mW
18-Pin SO (derate 9.52mW/°C above +70°C)..............762mW
18-Pin Plastic DIP (derate 11.11mW/°C above +70°C)..889mW
20-Pin SSOP (derate 7.00mW/°C above +70°C).........559mW
20-Pin TSSOP (derate 8.0mW/°C above +70°C).............640mW
28-Pin TSSOP (derate 8.7mW/°C above +70°C).............696mW
28-Pin SSOP (derate 9.52mW/°C above +70°C).........762mW
28-Pin SO (derate 12.50mW/°C above +70°C).....................1W
Operating Temperature Ranges
MAX32_ _C_ _.....................................................0°C to +70°C
MAX32_ _E_ _ .................................................-40°C to +85°C
Storage -65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
Note 1:V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DC CHARACTERISTICS
V
CC
Power-Supply Current
Shutdown Supply Current
Input Logic Threshold Low
(Note 3)
Input Logic Threshold High
(Note 3)
Input Leakage Current
Output Leakage Current
Output Voltage Low
Output Voltage High
RECEIVER INPUTS
Input Voltage Range
Input Threshold Low
Input Threshold High
T
A
= +25°C
T
A
= +25°C
V
CC
= 5.0V
V
CC
= 3.3V
V
CC
= 5.0V
V
CC
= 3.3V
V
CC
= 5.0V
-25
0.6
0.8
1.2
1.5
1.5
1.8
2.4
2.4
25V
V
V
No load, V
CC
= 3.3V or 5.0V,
T
A
= +25°C
SHDN= GND, T
A
= +25°C
MAX3222/MAX3232/
MAX3241
MAX3237
0.3
0.5
1.0
1.0
2.0
10µA
mA
CONDITIONS
MINTYPMAX
UNITS
LOGIC INPUTS AND RECEIVER OUTPUTS
T_IN, EN, SHDN, MBAUD
V
CC
= 3.3V
V
CC
= 5.0V
T_IN, EN, SHDN, MBAUD
Receivers disabled
I
OUT
= 1.6mA
I
OUT
= -1.0mAV
CC
- 0.6V
CC
- 0.1
2.0
2.4
±0.01
±0.05
±1.0
±10
0.4
0.8V
V
µA
µA
V
V
2_______________________________________________________________________________________
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Input Hysteresis
Input Resistance
TRANSMITTER OUTPUTS
Output Voltage Swing
Output Resistance
Output Short-Circuit Current
Output Leakage Current
V
OUT
= ±12V, V
CC
= 0V or 3V to 5.5V, transmitters
disabled
All transmitter outputs loaded with 3kΩto ground
V
CC
= V+ = V- = 0V, V
OUT
= ±2V
±5.0
300
±5.4
10M
±35±60
±25
V
Ω
mA
µA
T
A
= +25°C3
CONDITIONS
MINTYP
0.3
57
MAX
UNITS
V
kΩ
MAX3222/MAX3232/MAX3237/MAX3241
MOUSE DRIVEABILITY (MAX3241)
Transmitter Output Voltage
T1IN = T2IN = GND, T3IN = V
CC
,
T3OUT loaded with 3kΩto GND,
T1OUT and T2OUT loaded with 2.5mA each
±5.0V
TIMING CHARACTERISTICS—MAX3222/MAX3232/MAX3241
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Maximum Data Rate
Receiver Propagation Delay
Receiver Output Enable Time
Transmitter Skew
CONDITIONS
R
L
= 3kΩ, C
L
= 1000pF, one transmitter switching
R_IN to R_OUT, C
L
= 150pF
Normal operation
t
PHL
t
PLH
MIN
120
TYP
235
0.3
0.3
200
200
300
MAX
UNITS
kbps
µs
ns
ns
ns
Receiver Output Disable TimeNormal operation
|
t
PHL
- t
PLH
|
Receiver Skew
|
t
PHL
- t
PLH
|
300ns
V
CC
= 3.3V, R
L
= 3kΩto 7kΩ,
C
L
= 150pF to
Transition-Region Slew Rate
+3V to -3V or -3V to +3V,
1000pF
630
T
A
= +25°C, one transmitter
switching
C
V/µs
L
= 150pF to
2500pF
430
_______________________________________________________________________________________3
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
M
A
X
3
2
2
2
/
M
A
X
3
2
3
2
/
M
A
X
3
2
3
7
/
M
A
X
3
2
4
1
TIMING CHARACTERISTICS—MAX3237
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETERCONDITIONS
R
L
= 3kΩ, C
L
= 1000pF, one transmitter switching,
MBAUD = GND
Maximum Data Rate
V
CC
= 3.0V to 4.5V, R
L
= 3kΩ, C
L
= 250pF,
one transmitter switching, MBAUD = V
CC
V
CC
= 4.5V to 5.5V, R
L
= 3kΩ, C
L
= 1000pF,
one transmitter switching, MBAUD = V
CC
Receiver Propagation Delay
Receiver Output Enable Time
R_IN to R_OUT, C
L
= 150pF
Normal operation
t
PHL
t
PLH
MIN
250
1000
1000
0.15
0.15
200
200
100
25
50
C
L
= 150pF
to 1000pF
MBAUD =
GND
MBAUD =
V
CC
6
24
4
30
150
30
V/µs
µs
ns
ns
ns
ns
ns
kbps
TYPMAX
UNITS
Receiver Output Disable TimeNormal operation
Transmitter Skew
Receiver Skew
|
t
PHL
- t
PLH
|
, MBAUD = GND
|
t
PHL
- t
PLH
|
, MBAUD = V
CC
|
t
PHL
- t
PLH
|
Transition-Region Slew Rate
V
CC
= 3.3V, R
L
= 3Ωto 7kΩ,
+3V to -3V or -3V to +3V,
T
A
= +25°C
C
L
= 150pF to 2500pF,
MBAUD = GND
Note 2:MAX3222/MAX3232/MAX3241: C1–C4 = 0.1µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested at 5.0V ±10%.
MAX3237: C1–C4 = 0.1µF tested at 3.3V ±5%; C1–C4 = 0.22µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested
at 5.0V ±10%.
Note 3:Transmitter input hysteresis is typically 250mV.
_________________________________________________________________________典型工作特性
(V
CC
= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, T
A
= +25°C, unless otherwise noted.)
MAX3222/MAX3232
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
M
A
X
3
2
2
2
-
0
1
MAX3222/MAX3232
SLEW RATE
vs. LOAD CAPACITANCE
20
18
S
L
E
W
R
A
T
E
(
V
/
µ
s
)
16
14
12
10
8
6
4
2
0
5000
150
10005000
+SLEW
-SLEW
FOR DATA RATES UP TO 235kbps
M
A
X
3
2
2
2
-
0
2
MAX3222/MAX3232
SUPPLY CURRENT vs. LOAD CAPACITANCE
WHEN TRANSMITTING DATA
35
S
U
P
P
L
Y
C
U
R
R
E
N
T
(
m
A
)
30
25
120kbps
20
15
20kbps
10
5
0
0
10005000
M
A
X
3
2
2
2
-
0
3
T
R
A
N
S
M
I
T
T
E
R
O
U
T
P
U
T
V
O
L
T
A
G
E
(
V
)
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
0
1
22
40
235kbps
V
OUT
+
V
OUT
-
4000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
4_______________________________________________________________________________________
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
____________________________________________________________________典型工作特性(续)
(V
CC
= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, T
A
= +25°C, unless otherwise noted.)
MAX3241
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
M
A
X
3
2
2
2
-
0
4
MAX3222/MAX3232/MAX3237/MAX3241
MAX3241
SLEW RATE
vs. LOAD CAPACITANCE
M
A
X
3
2
2
2
-
0
5
MAX3241
SUPPLY CURRENT vs. LOAD
CAPACITANCE WHEN TRANSMITTING DATA
40
S
U
P
P
L
Y
C
U
R
R
E
N
T
(
m
A
)
35
30
25
20
15
10
5
0
5000
0
10005000
LOAD CAPACITANCE (pF)
20kbps
120kbps
235kbps
M
A
X
3
2
2
2
-
0
6
7.5
T
R
A
N
S
M
I
T
T
E
R
O
U
T
P
U
T
V
O
L
T
A
G
E
(
V
)
V
OUT
+
5.0
2.5
0
-2.5
-5.0
-7.5
0
1000
V
OUT
-
24
22
20
S
L
E
W
R
A
T
E
(
V
/
µ
s
)
18
16
14
12
10
8
6
4
+SLEW
ALL OUTPUTS LOADED WITH 3kΩ +C
L
0.1µF CHARGE-PUMP CAPACITORS
FOR ALL DATA RATES UP TO 235kbps
0
1000
LOAD CAPACITANCE (pF)
45
1 TRANSMITTER AT 235kbps
2 TRANSMITTERS AT 30kbps
-SLEW
5000
LOAD CAPACITANCE (pF)
MAX3237
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = GND)
M
A
X
3
2
2
2
-
0
7
MAX3237
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = V
CC
)
R
A
N
S
M
I
T
T
E
R
O
U
T
P
U
T
V
O
L
T
A
G
E
(
V
)
1Mbps
5.0
2.5
0
-2.5
-5.0
2Mbps
1.5Mbps
2
2Mbps
1.5Mbps
M
A
X
3
2
2
2
-
0
8
MAX3237
SLEW RATE vs. LOAD CAPACITANCE
(MBAUD = GND)
M
A
X
3
2
2
2
-
0
9
7.5
R
A
N
S
M
I
T
T
E
R
O
U
T
P
U
T
V
O
L
T
A
G
E
(
V
)
5.0
2.5
0
-2.5
-5.0
7.5
12
10
S
L
E
W
R
A
T
E
(
V
/
µ
s
)
8
6
4
1 TRANSMITTER AT 240kbps
4 TRANSMITTERS AT 15kbps
3kΩ + C
L
LOADS
+SLEW
-SLEW
1 TRANSMITTER AT 240kbps
4 TRANSMITTERS AT 15kbps
3kΩ + C
L
LOADS
V
CC
= 3.3V
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
3kΩ + C
L
LOAD, EACH OUTPUT
V
CC
= 3.3V
T
T
1Mbps
V
CC
= 3.3V
-7.5
-7.5
0
0
10005000
0
500
0
10005000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
MAX3237
MAX3237
MAX3237
SLEW RATE vs. LOAD CAPACITANCE
SUPPLY CURRENT vs.
SKEW vs. LOAD CAPACITANCE
(MBAUD = V
CC
)
LOAD CAPACITANCE (MBAUD = GND)
(t
PLH
- t
PHL
)
70
0
60
1
1
1
70
2
-
-
2
2
1
-
2
2
2
2
)
3
3
X
X
1 TRANSMITTER AT 512kbps
2
s
2
2
A
A
M
M
60
n
4 TRANSMITTERS AT 32kbps
3
X
60
(
A
M
-SLEW, 1Mbps
50
W
)
240kbps
A
E
3kΩ + C
K
)
s
50
+SLEW, 1Mbps
m
(
50
S
V
= 3.3V
L
LOADS
µ
MBAUD = V
CC
CC
/
T
40
120kbps
V
-SLEW, 2Mbps
N
(
E
E
+SLEW, 2Mbps
R
T
40
40
MAX
A
R
R
U
30
C
AVERAGE; 10 PARTS
W
30
Y
20kbps
30
E
L
L
P
S
P
20
20
U
1 TRANSMITTER AT FULL DATA RATE
S
1 TRANSMITTER AT FULL DATA RATE
20
10
4 TRANSMITTERS AT 1/16 DATA RATE
3kΩ + C
10
4 TRANSMITTERS AT 1/16 DATA RATE
L
LOAD EACH OUTPUT
3kΩ + C
L
LOADS
10
V
MIN
CC
= 3.3V
0
V
CC
= 3.3V
0
0
500
0
10005000
0
0
5002500
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
_______________________________________________________________________________________5
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
M
A
X
3
2
2
2
/
M
A
X
3
2
3
2
/
M
A
X
3
2
3
7
/
M
A
X
3
2
4
1
__________________________________________________________________________引脚说明
引脚
MAX3222
DIP/SO
1
2
3
4
5
6
7
8, 15
9, 14
10, 13
11, 12
16
17
18
—
—
—
SSOP
1
2
3
4
5
6
7
8, 17
9, 16
10, 15
12, 13
18
19
20
11, 14
—
—
MAX3232
—
1
2
3
4
5
6
7, 14
8, 13
9, 12
10, 11
15
16
—
—
—
—
MAX3237
13
28
27
25
1
3
4
5, 6, 7,
10, 12
8, 9, 11
18, 20, 21
17, 19, 22,
23, 24
2
26
14
—
15
16
MAX3241
23
28
27
24
1
2
3
9, 10, 11
4–8
15–19
12, 13, 14
25
26
22
—
—
20, 21
名称功能
EN
C1+
V+
C1-
C2+
C2-
V-
T_OUT
R_IN
R_OUT
T_IN
GND
V
CC
SHDN
N.C.
MBAUD
R_OUTB
接收器使能，低电平有效。
倍压电荷泵电容的正端。
电荷泵产生的+5.5V。
倍压电荷泵电容的负端。
反相电荷泵电容的正端。
反相电荷泵电容的负端。
电荷泵产生的-5.5V。
RS-232发送器输出。
RS-232接收器输入。
TTL/CMOS接收器输出。
TTL/CMOS发送器输入。
地。
+3.0V至+5.5V供电电源。
关断控制，低电平有效。
没有连接。
MegaBaud控制输入。连接至GND时，工作在常规速率；
连接至V
CC
时传输速率达1Mbps。
同相互补接收器输出，始终保持有效。
6_______________________________________________________________________________________
3.0V至5.5V、低功耗、1Mbps、真RS-232收发器，
使用四只0.1
µ
F外部电容
_______________________________详细说明
双电荷泵电压转换器
MAX3222/MAX3232/MAX3237/MAX3241的内部电源由两路
稳压型电荷泵组成，只要输入电压(V
CC
)在3.0V至5.5V范围
以内，即可提供+5.5V(倍压电荷泵)和-5.5V(反相电荷泵)
输出电压。电荷泵工作在非连续模式，一旦输出电压低于
5.5V，将开启电荷泵；输出电压超过5.5V时，即刻关闭电
荷泵。每个电荷泵需要一个飞电容(C1、C2)和一个储能电
容(C3、C4)，产生V+和V-电压。
器件处于关断模式时，MAX3222/MAX3237/MAX3241输
出级关断(置为高阻)。关闭电源时，MAX3222/MAX3232/
MAX3237/MAX3241允许输出端驱动至最高±12V。
发送器输入没有上拉电阻，将未使用的输入连接至GND或
V
CC
。
MAX3222/MAX3232/MAX3237/MAX3241
MAX3237 MegaBaud工作模式
常规工作模式(MBAUD=GND)下，MAX3237发送器能够在
最差工作条件(3kΩ电阻与1000pF电容的并联负载)下保证
250kbps的数据速率，提供PC至PC通信软件(例如LapLink)
的兼容性。
为了获得更高的串行通信速率，MAX3237提供MegaBaud工
作模式。在MegaBaud工作模式(MBAUD=V
CC
)下，MAX3237
发送器能够在最差工作条件(3kΩ电阻与250pF电容的并联负
载，3.0V CC <4.5V)下保证1Mbps的数据速率。5V±10% 供电时，MAX3237发送器能够在最差工作条件(3kΩ电阻与 1000pF电容的并联负载)下保证1Mbps的数据速率。 RS-232发送器 发送器为反相电平转换器，将CMOS逻辑电平转换成5.0V EIA/TIA-232电平。 MAX3222/MAX3232/MAX3241在最差工作条件(3kΩ电阻与 1000pF电容的并联负载)下能够保证120kbps的数据速率， 提供PC至PC通信软件(例如LapLink TM )兼容性。通常情况下， 这三款器件能够工作于235kbps数据速率。发送器可并联驱 动多个接收器或鼠标。 LapLink是Traveling Software, Inc.的商标。 * MAX3222/MAX3237/MAX3241 ONLY 图1. 摆率测试电路 _______________________________________________________________________________________7 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 M A X 3 2 2 2 / M A X 3 2 3 2 / M A X 3 2 3 7 / M A X 3 2 4 1 RS-232接收器 V CC 接收器将RS-232信号转换成CMOS逻辑输出电平，MAX3222/ MAX3237/MAX3241接收器提供反相三态输出。关断模式 下，接收器可处于有效或无效状态(表1)。 PREVIOUS RS-232 V CC Rx PROTECTION DIODE UART Tx GND SHDN = GND MAX3237(R1OUTB)和MAX3241(R1OUTB、R2OUTB)互补 输出始终保持有效，与 EN 或 SHDN 状态无关。这些器件适 用于振铃指示器等应用，不需要正向偏置连接到接收器输 出端的其它器件。该功能可理想用于在关断模式下将V CC 置为0V以适应外设操作(例如UART)的系统(图2)。 5kΩ MAX3222/MAX3237/MAX3241关断模式 关断模式( SHDN =低电平)下，电源电流降至1µA以内。关 断时，器件的电荷泵关闭，V+下拉至V CC ，V-拉至地电位， 发送器输出被禁止(高阻)。退出关断模式的时间通常为100µs， 如图3所示。如果不使用关断模式，则将 SHDN 连接至V CC 。 SHDN 不影响R_OUT或R_OUTB。 a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM ACTIVE RECEIVER OUTPUT IN SHUTDOWN. MAX3222/MAX3237/MAX3241使能控制 当 EN 为高电平时，反相接收器输出(R_OUT)置为高阻态。 互补输出R1OUTB和R2OUTB始终保持有效，与 EN 和 SHDN 的状态无关(表1)， EN 不影响T_OUT。 V CC TO µP LOGIC TRANSITION DETECTOR _______________________________应用信息 注意！！！！！ MAX3237 MAX3241 R1OUTB 电容选择 C1至C4所使用的电容类型对于正常工作影响不大，可以使 用有极性或无极性电容。3.3V供电时，电荷泵需要0.1µF 电容；其它供电电压下的电容选择请参考表2，不要使用 低于表2所列容值的电容。增大电容值(例如增大2倍)有助 于降低发送器输出的纹波，并对降低功耗略有帮助。可以 不改变C1，只是增大C2、C3和C4。但是，请勿在C2、C3 和C4没有增大的情况下增大C1，需维持这些电容之间的适 当比值(C1相对于其它电容)。 如果使用了所要求的最小电容，请确保电容值不会随着温 度的变化而出现明显的下降。如果不能确保这一条件，请 使用具有较高标称值的电容。电容等效串联电阻(ESR)通常 在低温下增大，它会影响V+和V-的纹波。 V CC Rx PROTECTION DIODE UART Tx GND T1IN SHDN = GND R1OUT EN = V CC 5kΩ T1OUT R1IN b) NEW MAX3237/MAX3241: EN SHUTS DOWN RECEIVER OUTPUTS (EXCEPT FOR B OUTPUTS), SO NO CURRENT FLOWS TO UART IN SHUTDOWN. B OUTPUTS INDICATE RECEIVER ACTIVITY DURING SHUTDOWN WITH EN HIGH. 图2. 当UART和接口关断时，RS-232的有效检测；MAX3237/ MAX3241 (b)与早期收发器(a)的比较 8_______________________________________________________________________________________ 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 表1. MAX3222/MAX3237/MAX3241关断和 使能控制真值表 SHDN 0 0 1 1 EN 0 1 0 1 T_OUT High-Z High-Z Active Active R_OUT Active High-Z Active High-Z R_OUTB (MAX3237/ MAX3241) Active Active Active Active 电源去耦 大多数情况下，使用一个0.1µF旁路电容即可满足要求。 在对电源噪声敏感的应用中，采用与电荷泵电容C1相同 的电容将V CC 旁路到地，进行去耦。旁路电容应尽量靠近 IC放置。 MAX3222/MAX3232/MAX3237/MAX3241 工作在最低2.7V 当电源电压低至2.7V时，发送器输出仍可满足EIA/TIA- 562要求的±3.7V电平。 退出关断模式时发送器的输出 表2. 所要求的最小电容值 V CC (V) C1 (µF) C2, C3, C4 (µF) MAX3222/MAX3232/MAX3241 3.0 to 3.6 4.5 to 5.5 3.0 to 5.5 MAX3237 3.0 to 3.6 3.15 to 3.6 4.5 to 5.5 3.0 to 5.5 0.22 0.1 0.047 0.22 0.22 0.1 0.33 1.0 0.1 0.047 0.1 0.1 0.33 0.47 图3所示为退出关断模式时的两路发送器输出。当两路发 送器输出有效时，发送器输出与RS-232电平反相的信号 (一路发送器输入为高电平，另一路为低电平)。每个发送 器负载为3kΩ电阻并联2500pF电容。退出关断模式时，发 送器输出显示没有振铃，也不存在所不希望的瞬变电压。 注意，只有在V-幅值超过3V左右时，才会使能发送器。 鼠标驱动能力 MAX3241设计用于串口鼠标驱动，能够工作在较低的电源 电压。该器件经过一些重要的鼠标生产厂家的测试，例如 Microsoft和Logitech。MAX3241能够成功驱动所有测试的串 口鼠标，满足相应的电流、电压要求。图4a所示为3.0V供 电时，发送器输出电压随负载电流的变化情况；图4b所示 为使用MAX3241时典型的鼠标连接。 5V/div T2 2V/div T1 50µs/div V CC = 3.3V C1–C4 = 0.1µF 图3. 退出关断模式或上电时发送器的输出 _______________________________________________________________________________________9 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 M A X 3 2 2 2 / M A X 3 2 3 2 / M A X 3 2 3 7 / M A X 3 2 4 1 T R A N S M I T T E R O U T P U T V O L T A G E ( V ) 4 3 2 1 0 -1 -2 -3 -4 -5 -6 01234567 LOAD CURRENT PER TRANSMITTER (mA) V CC V CC = 3.0V T1 V OUT + V OUT + T2 T3 V OUT - V OUT - 图4a. MAX3241每路发送器输出电压与负载电流之间的关系 V CC = 3V to 5.5V 0.1µF 26 V CC 27 C3 COMPUTER SERIAL PORT 3 C4 9 +V 10 11 +V -V GND R1IN4 5kΩ 5kΩ! 5kΩ! 5kΩ! 5kΩ! GND 25 SHDN R2IN5 R3IN 6 R4IN 7 MOUSE R5IN8 22 Tx 28 C 1 24 1 C 2 2 14 13 V CC 12 21 20 19 18 17 16 15 23 C1+ C1- C2+ C2- T1IN T2IN T3IN R1OUTB R2OUTB R1OUT R2OUT R3OUT R4OUT R5OUT EN V+ MAX3241 V- T1OUT T2OUT T3OUT 图4b. 鼠标驱动测试电路 10______________________________________________________________________________________ M A X 3 2 2 2 - 0 4 6 5 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 MAX3222/MAX3232/MAX3237/MAX3241 V CC 0.1µF V CC V+ C3 C1- C2+ C2 C2- R1OUT 5V/div T1IN 5V/div C1+ C1 T1OUT 5V/div MAX3222 MAX3232 MAX3237 MAX3241 V- C4 5µs/div V CC = 3.3V T_ IN T_ OUT 图6. MAX3241在120kbps数据速率下的环回测试结果 R_ OUT 0V V CC EN * R_ IN 5kΩ 1000pF T1IN 5V/div SHDN * GND T1OUT 5V/div * MAX3222/MAX3237/MAX3241 ONLY R1OUT 5V/div 图5. 环回测试电路 V CC = 3.3V 2µs/div 高数据速率 图7. MAX3241在235kbps数据速率下的环回测试结果 即使工作在高数据速率下，MAX3222/MAX3232/MAX3241 仍然能够保持RS-232标准要求的±5.0V最小发送器输出电 压。图5所示为发送器环回测试电路，图6所示为120kbps +5V 数据速率下的环回测试结果，图7所示为235kbps数据速率 0V T_IN 下的相同测试。图6中，所有发送器同时以120kbps的数据 +5V 速率驱动并联了1000pF电容的RS-232负载。图7中，单个 发送器工作在235kbps数据速率，所有发送器的负载都是 0V T_OUT = R_IN 并联了1000pF电容的RS-232接收器。 -5V 5kΩ + 250pF MAX3237在高达1Mbps的数据速率下能够保持RS-232标准 +5V 要求的±5.0V最小发送器输出电压。图8所示为1Mbps下， 0V R_OUT 150pF MBAUD = V CC 时电路的环回测试结果。对于图8，所有发 送器负载为并联了250pF电容的RS-232接收器。 V 200ns/div CC = 3.3V 图8. MAX3237在1000kbps (MBAUD = V CC )数据速率下的环回测试 结果 ______________________________________________________________________________________11 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 M A X 3 2 2 2 / M A X 3 2 3 2 / M A X 3 2 3 7 / M A X 3 2 4 1 与3V和5V逻辑电平互联 MAX3222/MAX3232/MAX3237/MAX3241可直接与各种5V 逻辑电平接口，包括ACT和HCT CMOS。表3列出了各种 可能的互联组合的详细信息。 表3. 不同电源电压下的逻辑电平兼容性 SYSTEM POWER- SUPPLY VOLTAGE (V) 3.3 5 MAX32_ _ V CC SUPPLY VOLTAGE (V) 3.3 5 COMPATIBILITY Compatible with all CMOS families. Compatible with all TTL and CMOS-logic families. Compatible with ACT and HCT CMOS, and with TTL. Incompatible with AC, HC, and CD4000 CMOS. 53.3 ______________________________________________________________________典型工作电路 +3.3V 0.1µF C1 0.1µF 2 C1+ 4 5 C2 0.1µF 6 C1- C2+ C2- T1OUT 15 RS-232 OUTPUTS 11 T2IN T2OUT 8 TTL/CMOS INPUTS 10 T2IN T2OUT 7 17 V CC V+ 3 C3 * 0.1µF 7 C4 0.1µF 0.1µF 0.1µF +3.3V 0.1µF 1 C1+ 3 4 5 C1- C2+ C2- T1OUT 14 RS-232 OUTPUTS 16 V CC V+ 2 C3 * 0.1µF 6 C4 0.1µF MAX3222 V- MAX3232 V- 12 T1IN TTL/CMOS INPUTS 11 T1IN 13R1OUT TTL/CMOS OUTPUTS 10R2OUT 1 EN GND 16 R1IN 14 5kΩ R2IN 9 5kΩ SHDN 18 RS-232 INPUTS TTL/CMOS OUTPUTS 12R1OUT R1IN 13 5kΩ RS-232 INPUTS 9R2OUT R2IN 8 5kΩ GND 15 PIN NUMBERS REFER TO DIP/SO PACKAGES. * C3 CAN BE RETURNED TO EITHER V CC OR GROUND. SEE TABLE 2 FOR CAPACITOR SELECTION * C3 CAN BE RETURNED TO EITHER V CC OR GROUND. 12______________________________________________________________________________________ 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 ___________________________________________________________________典型工作电路(续) MAX3222/MAX3232/MAX3237/MAX3241 0.1µF 26 28 C1+ 25 C1- 1 0.1µF 3 C2+ C2- T1 T2 T3 T4 T5 T1OUT5 T2OUT6 T3OUT 7 T4OUT10 20 R2OUTB T5OUT 12 19 R1OUT R1IN 4 5kΩ R1IN 8 5kΩ 20 R2OUT R2IN9 RS-232 TTL/CMOS OUTPUTS 18 R2OUT R2IN 5kΩ 17 R3OUT R3IN 6 RS-232 5 RS-232 OUTPUTS V CC V+ 27 0.1µF 4 0.1µF 0.1µF +3.3V 0.1µF 0.1µF 28 C1+ 24 C1- 26 V CC V+ 27 C3 * 0.1µF 3 C4 0.1µF 0.1µF MAX3237 V- 1 2 C2+ C2- MAX3241 V- 24 T1IN 23 T2IN LOGIC INPUTS 22 T3IN 19 T4IN 17 T5IN 16 R1OUTB 14 T1IN 13 T2IN 12 T3IN 21 R1OUTB T1OUT9 T2OUT10 T3OUT 11 TTL/CMOS INPUTS RS-232 OUTPUTS 21 R1OUT R1 LOGIC R2 OUTPUTS INPUTS INPUTS 5kΩ 5kΩ 18 R3OUT 16 R4OUT R4IN 7 R3 R3IN 11 5kΩ 5kΩ 15 R5OUT R5IN8 MBAUD 15 5kΩ 13 EN 14 23 EN GND SHDN GND SHDN 22 2 25 * C3 CAN BE RETURNED TO EITHER V CC OR GROUND. * C3 CAN BE RETURNED TO EITHER V CC OR GROUND. ______________________________________________________________________________________13 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 M A X 3 2 2 2 / M A X 3 2 3 2 / M A X 3 2 3 7 / M A X 3 2 4 1 _______________________________________________________________________引脚配置(续) TOP VIEW + EN 1 C1+ 2 V+ 3 C1- 4 C2+ 5 C2- 6 V- 7 T2OUT 8 R2IN 9 R2OUT 10 20 SHDN 19 V CC 18 GND 17 T1OUT C1+ 1 V+ 2 C1- 3 C2+ 4 C2- 5 V- 6 T2OUT 7 R2IN 8 + 16 V CC 15 GND 14 T1OUT MAX3222 16 R1IN 15 R1OUT 14 N.C. 13 T1IN 12 T2IN 11 N.C. MAX3232 13 R1IN 12 R1OUT 11 T1IN 10 T2IN 9 R2OUT DIP/SO/SSOP/TSSOP SSOP/TSSOP + C2+ GND C2- V- T1OUT T2OUT T3OUT R1IN R2IN 1 2 3 4 5 6 7 8 9 + 28 C1+ 27 V+ 26 V CC 25 C1- C2+ C2- V- R1IN R2IN R3IN R4IN R5IN T1OUT 1 2 3 4 5 6 7 8 9 28 C1+ 27 V+ 26 V CC 25 GND MAX3237 24 T1IN 23 T2IN 22 T3IN 21 R1OUT 20 R2OUT 19 T4IN 18 R3OUT 17 T5IN 16 R1OUTB 15 MBAUD MAX3241 24 C1- 23 EN 22 SHDN 21 R1OUTB 20 R2OUTB 19 R1OUT 18 R2OUT 17 R3OUT 16 R4OUT 15 R5OUT T4OUT 10 R3IN 11 T5OUT 12 EN 13 SHDN 14 T2OUT 10 T3OUT 11 T3IN 12 T2IN 13 T1IN 14 SSOP SO/SSOP/TSSOP 14______________________________________________________________________________________ 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 _______________________________________________________________________定购信息(续) PART MAX3222EUP+ MAX3222EAP+ MAX3222EWN+ MAX3222EPN+ MAX3222C/D MAX3232CUE+ MAX3232CSE+ MAX3232CWE+ MAX3232CPE+ MAX3232EUE+ MAX3232ESE+ TEMP RANGE -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C 0°C to +70°C 0°C to +70°C 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C PIN-PACKAGE 20 TSSOP 20 SSOP 18 SO 18 Plastic Dip Dice* 16 TSSOP 16 Narrow SO 16 Wide SO 16 Plastic DIP 16 TSSOP 16 Narrow SO PKG CODE U20+2 A20+1 W18+1 P18+5 — U16+1 S16+1 W16+1 P16+1 U16+1 S16+5 PART MAX3232EWE+ MAX3232EPE+ MAX3232CAE+ MAX3237CAI+ MAX3237EAI+ MAX3241CAI+ MAX3241CWI+ MAX3241EUI+ MAX3241EAI+ MAX3241EWI+ TEMP RANGE -40°C to +85°C -40°C to +85°C 0°C to +70°C 0°C to +70°C -40°C to +85°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -40°C to +85°C PIN-PACKAGE 16 Wide SO 16 Plastic DIP 16 SSOP 28 SSOP 28 SSOP 28 SSOP 28 SO 28 TSSOP 28 SSOP 28 SO PKG CODE W16+1 P16+1 A28+2 A28+1 A28+1 A28+1 W28+6 U28+2 A28+1 W28+6 MAX3222/MAX3232/MAX3237/MAX3241 * 裸片在T A = +25 ° C下经过测试，仅限直流参数。 + 表示无铅封装。 __________________________________Maxim提供的3V供电EIA/TIA-232和EIA/TIA-562收发器 POWER- SUPPLY VOLTAGE (V) 3.0 to 3.6 1.8 to 4.25 2.7 to 5.25 3.0 to 3.6 No. OF TRANSMITTERS/ RECEIVERS 3/5 2/2 3/5 2/2 No. OF RECEIVERS ACTIVE IN SHUTDOWN 5 2 5 2 GUAR- ANTEED DATA RATE (kbps) 120 120 230 230 EIA/ TIA-232 OR 562 232 232 562 562 PARTFEATURES MAX212 MAX218 MAX562 MAX563 Drives mice Operates directly from batteries without a voltage regulator Wide supply range 0.1µF capacitors AutoShutdown, complementary MAX32122.7 to 3.63/55235232receiver, drives mice, transient detection MAX32223.0 to 5.52/221202320.1µF capacitors MAX32233.0 to 5.52/221202320.1µF capacitors, AutoShutdown MAX32323.0 to 5.52/2N/A1202320.1µF capacitors 0.1µF capacitors, 1 complemen- MAX32373.0 to 5.55/33250/1000232tary receiver, MegaBaud operation MAX32413.0 to 5.53/55120232 0.1µF capacitors, 2 complemen- tary receivers, drives mice 0.1µF capacitors, AutoShutdown, MAX32433.0 to 5.53/51120232complementary receiver, drives mice ______________________________________________________________________________________15 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 M A X 3 2 2 2 / M A X 3 2 3 2 / M A X 3 2 3 7 / M A X 3 2 4 1 _______________________________芯片拓扑 MAX3222 V+C1+EN SHDN V CC _______________________________芯片信息 PART MAX3222 TRANSISTOR COUNT 339 339 1212 894 GND C1- C2+ T1OUT 0.127" (3.225mm) C2- MAX3232 MAX3237 MAX3241 R1IN V- R1OUT T2OUTR2INR2OUT 0.087" (2.209mm) T2INT1IN TRANSISTOR COUNT: 339 SUBSTRATE CONNECTED TO GND 16______________________________________________________________________________________ 3.0V至5.5V、低功耗、1Mbps、真RS-232收发器， 使用四只0.1 µ F外部电容 _____________________________________________________________________________ 封装信息 如需最近的封装外形信息和焊盘布局，请查询/packages。 MAX3222/MAX3232/MAX3237/MAX3241 T S S O P 4 . 4 0 m m . E P S _______________________________修订历史 Rev 7中的修改页：1、15、16、17 Maxim不对Maxim产品以外的任何电路使用负责，也不提供其专利许可。Maxim保留在任何时间、没有任何通报的前提下修改产品资料和规格的权利。 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ______________________17 ©2007 Maxim Integrated Products Maxim 是 Maxim Integrated Products, Inc. 的注册商标。 Narrow SO 窄体SO封装