2024年9月9日发(作者：花芳蕤)
Supertex inc.
Three Channel
LED Driver Demoboard
General Description
The HV9982DB1 is a three channel boost LED driver
demoboard using Supertex’s HV9982 LED Driver IC. The
LED driver can be used to drive RGB or multi channel
white LEDs from a 24V input. The LED string current can
be adjusted up to a maximum of 100mA. The demoboard
has good current matching between strings and an excellent
PWM dimming response, making it ideal for LED backlight
applications.
The HV9982DB1 uses the HV9982 LED driver IC to drive
three discontinuous conduction mode boost converters
at a 500kHz switching frequency. The clocks of the three
channels are phase shifted to provide ripple cancellation at
the input and thus reducing the input capacitor requirements.
The output current level can be adjusted using an external
voltage source at the REF terminal.
The HV9982DB1 includes hiccup mode protection for both
short circuit and open circuit conditions to ensure that it
recovers from a momentary fault condition. It also enables
the board to survive prolonged fault conditions without any
damage to both the driver as well as the LEDs.
HV9982DB1
Specifications
Parameter
Input voltage
LED string voltage (all channels)
LED current (all channels)
Switching frequency of the
converter at F
CLK
= 6.0MHz
External frequency at CLK pin
Current matching between
channels
Typical full load efficiency
PWM dimming
rise and fall times
PWM dimming frequency
(for analog control of PWM
dimming)
Shutdown mode current
Typical I
DD
current
(for all three channels)
Value
24V ± 10%
35V – 80V
100mA (max)
500kHz
6MHz
≤ ± 3%
90%
≤1μs
480Hz (typ)
≤ 600μA
12mA (V
DD
= 8V)
Included; hiccup-mode
Included; hiccup-mode
1ms (typ)
The HV9982DB1 also includes an on-board PWM generator
Open LED drotection
for analog control for PWM dimming (for backward
Output short circuit protection
compatibility with CCFL controllers). This feature enables
the user to PWM dim the driver with a 0 - 2.0V analog signal
Hiccup time
input and helps to achieve zero LED current with an analog
dimming input
Connection Diagram
24V DC source
- +
0 - 0.5V
DC source
+
-
6MHz clock
(TTL compatible)
Doc.# DSDB-HV9982DB1
A032913
Supertex inc.
HV9982DB1
Connections
Pin
VIN
GND, GND1
VDD
EN
CLK
Connection
This terminal is the positive input of the 24V supply for the boost converters. It is also the input for the
internal regulator of the IC.
These terminals are the return paths for all the input voltages and signals for the demoboard. All voltages
and signals (other than the output terminals) should be referenced to these two terminals.
This terminal is connected to the VDD pins of the IC. When left unconnected, the voltage at this terminal
will be regulated to 7.75V by the internal regulator of the HV9982. To supply the IC with an external VDD
supply, connect an 8-10V source to this terminal.
This terminal can be used to shut down the IC. Connecting this terminal to GND will cause the IC to go
into a standby mode and draw less than 500μA.
This terminal is the clock input to the IC. A TTL compatible 6MHz clock should be connected to this ter-
minal. In case an on-board clock is preferred, a 6MHz fixed frequency oscillator can be soldered in at U2
(please refer to BOM for the part number).
A 5.0V, 50mA source needs to be connected to this point, if an on-board clock is used. This provides
the power required for the fixed frequency oscillator at U2. This terminal can be left open if an external
6.0MHz clock is used.
This terminal is the control input for adjusting the LED current level. A 0 – 500mV voltage source should
be connected to this terminal.
These two switches on the demoboard control the PWM dimming function. They can be used to enable
either direct PWM dimming of the channels using an external TTL signal or analog control of PWM dim-
ming using a 0-2.0V analog signal. The control logic for these switches is given in Table 1.
These terminals are the PWM dimming inputs. The inputs can be either TTL compatible square wave
signals or 0-2.0V analog signals depending on the configuration of switches S1 and S2.
The anodes of the LED strings should be connected to these terminals as shown in the connection dia-
gram.
The cathodes of the LED strings should be connected to these terminals as shown in the connection
diagram.
This terminal is connected to the hiccup timing capacitor and can be used to measure the hiccup time.
This terminal can be used to synchronize the internal PWM ramp to an external clock. A TTL compatible,
350 – 400Hz external clock with a pulse width less than 2% can be applied at this terminal to synchronize
the internal ramp to the external clock.
5V
REF
S1, S2
PWMD1-3
VO+1-3
VO- 1-3
SKIP
SYNC
Table 1 : Truth Table for S1 and S2
S1
LO
LO
HI
HI
S2
LO
HI
LO
HI
PWMD Output
The output will follow PWMD input signal
Input DC zero volt corresponds to 100% duty cycle output
Input DC two volt corresponds to 100% duty cycle output
Doc.# DSDB-HV9982DB1
A032913
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Supertex inc.
HV9982DB1
Testing the Demoboard
Normal Operation – Connect the board as shown in the
connection diagram. Ensure that switches S1 and S2 are
LO. Turn on the clock, 24V supply and the reference volt-
age. Connect any of the PWMD pins to VDD. The LEDs of
the corresponding channel will light up. Measure the LED
current using an ammeter and the reference voltage using a
voltmeter. The current will be:
Analog Control of PWM Dimming – Change S1 and S2 as
required using Table 1. Connect the analog 0-2V source at
the PWMD terminal and turn on the demoboard. The LEDs
will dim and the LED current can be adjusted by varying the
analog voltage.
Open LED protection – Connect a voltage probe between
the VO+ terminal of any channel and GND and disconnect
V
I
LED
=
REF
± 3.0%the LED string. The output voltage will rise up to 92V and
(1)
4.99
trip the over voltage protection. At this point, all three chan-
nels will shut down and the output voltage of the channel
Current matching – Without changing the reference volt-with the open LED condition will be maintained hysteretically
age, enable each channel individually and measure the cur-between 92V and 82V until the output voltage of the fauly
rent (or, if possible, enable all channels and the three output channel falls below 82V or till the LED string is reconnected.
currents simultaneously). The error will be ≤ ± 3%.Once the LED string is reconnected, all three channels will
turn back on.
Linear Dimming – Vary the reference voltage between 0
– 500mV and measure the LED current. Short Circuit Protection – Short the output terminals of any
one channel using a jumper. All three channels shut down
The current will vary as per Eqn.1. This variation is fairly lin-and the IC tries restarting every 1.0ms. Once the short circuit
ear until the REF voltage gets very low. As the voltage goes is removed, all three channels come back into regulation.
below 50mV, the current will not match the reference voltage
as linearly.
PWM Dimming – With the reference voltage fixed at 0.5V,
apply a TTL compatible square wave signal (≤1kHz). The
LED current will dim based on the duty cycle of the PWM
input.
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Supertex inc.
HV9982DB1
Typical Results
Normal Operationboost converter and the parasitic capacitance at the drain
Fig.1 shows the waveforms during normal operation at full pin of the switching FET. This is a normal occurrence in any
load and 24V input. The smaller pulses in the drain wave-discontinuous mode converter.
forms represent the ringing between the input inductor of the
Fig. 1: Waveforms for Normal Operations
C1 (Yellow): Drain Waveform for Channel 1 (50V/div)
C2 (Pink): Drain Waveform for Channel 2 (50V/div)
C3 (Blue): Drain Waveform for Channel 3 (50V/div)
C4 (Green): Output Current for Channel 1 (100mA/div)
Time Scale: 1μs/div
Startup
Fig. 2 shows the startup waveforms. These waveforms were
obtained by connecting the PWMD pins to VDD and apply-
ing a step waveform at the 24V input. There is a 500μs delay
before the ramp voltage starts rising. This delay is due to the
time required to charge the capacitors at the VDD pins plus
the internal power-on-reset time. The other part of the delay
is the time required by the ramp capacitor to charge to 5V.
Once the RAMP voltage reaches 5V, the converter starts
switching and the LED current starts up slowly without any
overshoots.
Fig. 2: Startup Waveforms
C2 (Pink): RAMP waveform (2V/div)
C1 (Yellow): Input Voltage (10V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 500μs/div
Open LED Protection
Figs.3-6 show the over voltage protection in operation. Fig.
3 shows the open circuit condition occurring when the LED
current goes to zero. At this point, the output voltage starts
increasing since the energy from the input is used to charge
the output capacitors. Once the output voltage reaches 92V,
all three channels are shut down (Note: Output Voltage re-
fers to VO+ voltage GND). The hysteretic
over voltage protection is shown in Fig. 4 where the output
voltage is consistently maintained between 82V and 92V.
Fig. 3: Over Voltage Trigger
C1 (Yellow): Output Voltage of Channel 1 (20V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 20μs/div
Doc.# DSDB-HV9982DB1
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Supertex inc.
HV9982DB1
Fig. 4: Open LED Operation
C1 (Yellow): Output Voltage of Channel 1(20V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 20ms/div
The recovery from an open LED condition is shown in Fig. 5.
Two spikes are observed in the LED current. These spikes
are caused by the output capacitor discharging into the LEDs
since the capacitor voltage is higher the LED string voltage.
This causes the HV9982 to go into a hiccup mode short cir-
cuit condition till the capacitor voltage becomes lower than
the LED string voltage (as seen by the dip the output volt-
age). Once all fault conditions are cleared, the LED current
starts up smoothly into normal operation. Fig. 6 shows the
recovery with a smaller timescale.
Fig. 5: Recovery from Open LED Operation
C1 (Yellow): Output Voltage of Channel 1(20V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 20mA/div
Fig. 6: Recovery (smaller time scale)
C1 (Yellow): Output Voltage of Channel 1(20V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 500μs/div
Doc.# DSDB-HV9982DB1
A032913
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Supertex inc.
HV9982DB1
Short Circuit Protection
Figs. 7-9 show the operation of the short circuit protection.
Fig. 7 shows the response of the HV9982 to a short circuit
condition. The short circuit condition occurs when the output
current starts rising and the circuit shuts down in less than
200ns, providing a very fast response to an output short cir-
cuit (Note: LED string voltage refers to VO+ voltage mea-
its corresponding VO-).
The hiccup mode operation is shown in Fig. 8. The converter
tries to restart every 1ms and if the short circuit condition is
still detected, the converter shuts down.
The recovery from the short circuit condition is shown in Fig.
9. The LED current starts up without any overshoots.
Fig. 7: Waveforms for Normal Operations
C4 (Green): Output Current for Channel 1 (200mA/div)
Ma (Orange): LED String Voltage of Channel 1(20V/div)
Time Scale: 200ns/div
Fig. 8: Short Circuit Hiccup
C1 (Yellow): Output Voltage of Channel 1(20V/div)
C4 (Green): Output Current for Channel 1 (200mA/div)
Time Scale: 1ms/div
Fig. 9: Short Circuit Recovery
C1 (Yellow): Output Voltage of Channel 1(20V/div)
C4 (Green): Output Current for Channel 1 (200mA/div)
Time Scale: 500μs/div
Doc.# DSDB-HV9982DB1
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Supertex inc.
HV9982DB1
PWM Dimming Operation
PWM Dimming operation with an external TTL square wave
signal is shown in Figs. 10-12. Fig. 10 shows the overall op-
eration of the circuit with a PWM dimming input and Figs. 11
and 12 show the rise and fall times of the LED current during
PWM dimming.
In some cases, depending on the parasitic capacitance of
the LED string, there may be narrow spike in the LED cur-
rent during the rising edge. To prevent this spike from shut-
ting down the HV9982 due to a short circuit condition being
falsely detected, an internal 500ns blanking is provided in
the IC. Fig. 13 shows the rising edge of the PWM dimming
operation of the same LED driver with a different LED load
(which has a significant parasitic capacitance).
Fig. 10: PWM Dimming
C1 (Yellow): PWM Dimming Input for Channel 1(5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 500μs/div
Fig. 11: PWM Dimming – Rise Time
C1 (Yellow): PWM Dimming Input for Channel 1(5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 1μs/div
Fig. 12: PWM Dimming – Fall Time
C1 (Yellow): PWM Dimming Input for Channel 1(5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 1μs/div
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Supertex inc.
HV9982DB1
Fig. 13: Current Spike during PWM Dimming
C1 (Yellow): PWM Dimming Input for Channel 1(5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 500ns/div
Analog Control of PWM Dimming
The operation of the analog control of PWM dimming is
shown in Figs. 14-16. Fig. 14 shows the waveforms for op-
eration in one of the modes (S1=HI; S2=HI), with no external
SYNC signal applied. The plots in Figs. 15 and 16 show the
operation with an external 350Hz synchronizing clock. Fig.
15 shows the waveforms with S1=HI and S2=LO and Fig. 16
shows the waveforms with S1=HI and S2=HI. Fig. 17 shows
the variation of the average LED current with the voltage at
the PWMD pin in these modes of operation.
Fig. 14: Analog Control of PWM Dimming w/o external clock (S1 = HI and S2 = HI)
C3 (Blue): RAMP voltage (2V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 1ms/div
Fig. 15: Analog Control of PWM Dimming synchronized to external clock (S1 = HI and S2 = LO)
C2 (Pink): Signal at PWMD1 terminal (2V/div)
C3 (Blue): RAMP voltage (2V/div)
C1 (Yellow): External SYNC signal (5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 1ms/div
Fig. 16: Analog Control of PWM Dimming synchronized to external clock (S1 = HI and S2 = HI)
C2 (Pink): Signal at PWMD1 terminal (2V/div)
C3 (Blue): RAMP voltage (2V/div)
C1 (Yellow): External SYNC signal (5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 1ms/div
Doc.# DSDB-HV9982DB1
A032913
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Supertex inc.
HV9982DB1
Fig. 17: Analog Control of PWM Dimming - Measurements
120
Output Current vs. PWMD Voltage
100
L
E
D
C
u
r
r
e
n
t
(
m
A
)
80
60
S1 = HI
S2 = LO
S1 = HI
S2 = HI
40
20
0
-20
0 0.5 1.0 1.5 2
PWMD Voltage (V)
Circuit Schematic - Part 1 of 3
VIN
D1
DFLS1100-7
2
VIN
GND
GND1
C1
2.2µF
50V
C2
2.2µF
50V
R6
0.0
1/8W
VDD
VDD
1
L1
22µH
D2
VO+1
C3
0.33µF
100V
C4
0.33µF
100V
R1
845k
OVP1
D3
1N4148W
DFLS1100-7
0
C5
1.0µF
16V
R2
49.9k
VDD
U1A
8
0
9
C6
1.0µF
16V
11
0
C7
33nF
41
4
6
C8
1.0n
VIN
VDDA
GNDA
TH_PAD
COMP1
IREF1
GND1
1
HV9982
GATE1
CS1
FLT1
FDBK1
40
3
2
5
Q1
IRLM110A
VDD1
VO-1
R3
Q2
TN2510
0.27, 1/4W
REF
R4
1.0k
PWMD1OVP1
R5
4.99
1/8W
39 17 7
OVP1
C9
1.0n
0
F
PWMD1
IREF
Doc.# DSDB-HV9982DB1
A032913
9
Supertex inc.
HV9982DB1
Circuit Schematic - Part 2 of 3
VIN
C10
2.2µF
50V
1
D4
DFLS1100-7
2
L2
22µH
D5
VO+2
C1
0.33µF
100V
C12
0.33µF
100V
R9
845k
OVP2
D6
1N4148W
DFLS1100-7
VDD
VDD
F
C13
1.0µF
16V
EN
F
R10
100k
U1B
10
0
C14
2nF
C15
2nF
16
15
0
R13
1.0k
0
C17
1.0n
F
C16
33nF
12
13
EN
RAMP
GNDA
COMP2
IREF2
GND2
33
HV9982
GATE2
CS2
FLT2
FDBK2
35
37
36
38
Q3
IRLM110A
FF
R11
49.9k
F
VDD2
VO-2
R12
F
Q4
TN2510
SYNC
SKIP
0
0.27, 1/4W
Q7
R20
100k
IREF
PWMD2OVP2
R14
4.99
1/8W
34 18 14
F
OVP2
C18
1.0n
F
0
PWMD2
Circuit Schematic - Part 3 of 3
D7
DFLS1100-7
2
VIN
VDD
1
L3
22µH
D8
VO+3
VDD
0
VDD
0
C19
2.2µF
50V
DFLS1100-7
C20
0.33µF
100V
C21
0.33µF
100V
R15
845k
OVP3
D9
1N4148W
C22
1.0µF
16V
U1C
20
21
23
0
R18
1.0k
C24
1.0n
C23
33nF
27
25
S1
S2
CLK
COMP3
IREF3
GND3
33
HV9982
GATE3
CS3
FLT3
FDBK3
31
28
29
26
Q5
IRLM110A
VDD3
R16
49.9k
R17
VO-3
0.27, 1/4W
Q6
TN2510
IREF
PWMD3OVP3
R19
4.99
1/8W
32 19 24
PWMD3
C25
1.0n
OVP3
5.0V
C26
1.0µF
16V
1
2
OE
GND
VDD
OP
4
3
CLK
0
Doc.# DSDB-HV9982DB1
A032913
10
Supertex inc.
HV9982DB1
Bill of Materials
Item
Quan
#
120
RefDes
VO-1-3, VO+1-3,
PWMD1-3, GND,
GND1, VIN, VDD,
SKIP, REF, SYNC,
EN, CLK, 5V
C1,C2, C10,C19
C3,C4,
C11,C12,C20,C21
C5,C6, C13,C22,C26
C7,C16, C23
C8,C9,
C17,C18,C24,C25
C14,C15
D1,D2,D4,D5,D7,D8
D3,D6,D9
L1,L2,L3
Q1,Q3,Q5
Q2,Q4,Q6
Q7
R1,R9, R15
R2,R11, R16
R3,R12, R17
R4,R13, R18
R5,R14, R19
R6
R10,R20
SW1,SW2
U1
U2
DescriptionPackage
Manufac-
turer
Keystone
Electronics
Manufacturer’s
Part #
5016Compact surface mount test pointSMT
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
4
6
5
3
6
2
6
7
3
3
3
1
3
3
3
3
3
1
1
2
1
1
2.2µF, 50V, X7R ceramic chip
capacitor
0.33µF, 100V, metal film
capacitor
1µF, 16V, X7R ceramic
chip capacitor
33nF, 16V, X7R ceramic
chip capacitor
1nF, 50V, C0G ceramic
chip capacitor
2nF, 50V, C0G ceramic
chip capacitor
100V, 1A schottky diode
100V, 300mA switching diode
22uH, 1.2A rms, .5A sat inductor
100V, 0.44Ω, 1.5A N-channel
MOSFET
100V, 1.5Ω, N-channel MOSFET
30V, 1.6A N-channel MOSFET
845kΩ, 1/10W, 1% chip resistor
49.9kΩ, 1/10W, 1% chip resistor
0.27Ω, 1/4W, 5% chip resistor
1kΩ, 1/10W, 5% chip resistor
4.99Ω, 1/8W, 1% chip resistor
0.0Ω, 1/8W chip resistor
100kΩ, 1/10W, 1% chip resistor
SPDT Gull Wing slide switch
Three-channel closed-loop
LED Driver
6.176MHz fixed frequency
oscillator (optional)
SMD1206
Radial
SMD0603
SMD0603
SMD0603
SMD0603
Power
DI123
SOD-123
SMT
SOT-223
SOT-89
SOT-23
SMD0603
SMD0603
SMD1206
SMD0603
SMD0805
SMD0805
SMD0603
SMT
QFN-40
SMT
Murata
EPCOS Inc
Taiyo Yuden
Murata
Murata
Murata
Diodes Inc
Diodes Inc
Wurth
Electronik
Fairchild Semi
Supertex
Fairchild Semi
---
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---
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Copal
Electronics Inc
Supertex
Citizen
America
GRM31CR71H225KA88L
B32521C1334J
EMK107BJ105KA-TR
GRM188R71C333KA01D
GRM1885C2A102JA01D
GRM1885C1H202JA01D
DFLS1100-7
1N4148W-7
744774122
IRLM110A
TN2510N8
NDS355N
---
---
---
---
---
---
---
CJS-1200TB
HV9982K6-G
CSX750PCC6.1760M-UT
Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives
an adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability
to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and
specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//)
©2013
Supertex inc.
All rights reserved. Unauthorized use or reproduction is prohibited.
Supertex inc.
11
Doc.# DSDB-HV9982DB1
A032913
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
2024年9月9日发(作者：花芳蕤)
Supertex inc.
Three Channel
LED Driver Demoboard
General Description
The HV9982DB1 is a three channel boost LED driver
demoboard using Supertex’s HV9982 LED Driver IC. The
LED driver can be used to drive RGB or multi channel
white LEDs from a 24V input. The LED string current can
be adjusted up to a maximum of 100mA. The demoboard
has good current matching between strings and an excellent
PWM dimming response, making it ideal for LED backlight
applications.
The HV9982DB1 uses the HV9982 LED driver IC to drive
three discontinuous conduction mode boost converters
at a 500kHz switching frequency. The clocks of the three
channels are phase shifted to provide ripple cancellation at
the input and thus reducing the input capacitor requirements.
The output current level can be adjusted using an external
voltage source at the REF terminal.
The HV9982DB1 includes hiccup mode protection for both
short circuit and open circuit conditions to ensure that it
recovers from a momentary fault condition. It also enables
the board to survive prolonged fault conditions without any
damage to both the driver as well as the LEDs.
HV9982DB1
Specifications
Parameter
Input voltage
LED string voltage (all channels)
LED current (all channels)
Switching frequency of the
converter at F
CLK
= 6.0MHz
External frequency at CLK pin
Current matching between
channels
Typical full load efficiency
PWM dimming
rise and fall times
PWM dimming frequency
(for analog control of PWM
dimming)
Shutdown mode current
Typical I
DD
current
(for all three channels)
Value
24V ± 10%
35V – 80V
100mA (max)
500kHz
6MHz
≤ ± 3%
90%
≤1μs
480Hz (typ)
≤ 600μA
12mA (V
DD
= 8V)
Included; hiccup-mode
Included; hiccup-mode
1ms (typ)
The HV9982DB1 also includes an on-board PWM generator
Open LED drotection
for analog control for PWM dimming (for backward
Output short circuit protection
compatibility with CCFL controllers). This feature enables
the user to PWM dim the driver with a 0 - 2.0V analog signal
Hiccup time
input and helps to achieve zero LED current with an analog
dimming input
Connection Diagram
24V DC source
- +
0 - 0.5V
DC source
+
-
6MHz clock
(TTL compatible)
Doc.# DSDB-HV9982DB1
A032913
Supertex inc.
HV9982DB1
Connections
Pin
VIN
GND, GND1
VDD
EN
CLK
Connection
This terminal is the positive input of the 24V supply for the boost converters. It is also the input for the
internal regulator of the IC.
These terminals are the return paths for all the input voltages and signals for the demoboard. All voltages
and signals (other than the output terminals) should be referenced to these two terminals.
This terminal is connected to the VDD pins of the IC. When left unconnected, the voltage at this terminal
will be regulated to 7.75V by the internal regulator of the HV9982. To supply the IC with an external VDD
supply, connect an 8-10V source to this terminal.
This terminal can be used to shut down the IC. Connecting this terminal to GND will cause the IC to go
into a standby mode and draw less than 500μA.
This terminal is the clock input to the IC. A TTL compatible 6MHz clock should be connected to this ter-
minal. In case an on-board clock is preferred, a 6MHz fixed frequency oscillator can be soldered in at U2
(please refer to BOM for the part number).
A 5.0V, 50mA source needs to be connected to this point, if an on-board clock is used. This provides
the power required for the fixed frequency oscillator at U2. This terminal can be left open if an external
6.0MHz clock is used.
This terminal is the control input for adjusting the LED current level. A 0 – 500mV voltage source should
be connected to this terminal.
These two switches on the demoboard control the PWM dimming function. They can be used to enable
either direct PWM dimming of the channels using an external TTL signal or analog control of PWM dim-
ming using a 0-2.0V analog signal. The control logic for these switches is given in Table 1.
These terminals are the PWM dimming inputs. The inputs can be either TTL compatible square wave
signals or 0-2.0V analog signals depending on the configuration of switches S1 and S2.
The anodes of the LED strings should be connected to these terminals as shown in the connection dia-
gram.
The cathodes of the LED strings should be connected to these terminals as shown in the connection
diagram.
This terminal is connected to the hiccup timing capacitor and can be used to measure the hiccup time.
This terminal can be used to synchronize the internal PWM ramp to an external clock. A TTL compatible,
350 – 400Hz external clock with a pulse width less than 2% can be applied at this terminal to synchronize
the internal ramp to the external clock.
5V
REF
S1, S2
PWMD1-3
VO+1-3
VO- 1-3
SKIP
SYNC
Table 1 : Truth Table for S1 and S2
S1
LO
LO
HI
HI
S2
LO
HI
LO
HI
PWMD Output
The output will follow PWMD input signal
Input DC zero volt corresponds to 100% duty cycle output
Input DC two volt corresponds to 100% duty cycle output
Doc.# DSDB-HV9982DB1
A032913
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Supertex inc.
HV9982DB1
Testing the Demoboard
Normal Operation – Connect the board as shown in the
connection diagram. Ensure that switches S1 and S2 are
LO. Turn on the clock, 24V supply and the reference volt-
age. Connect any of the PWMD pins to VDD. The LEDs of
the corresponding channel will light up. Measure the LED
current using an ammeter and the reference voltage using a
voltmeter. The current will be:
Analog Control of PWM Dimming – Change S1 and S2 as
required using Table 1. Connect the analog 0-2V source at
the PWMD terminal and turn on the demoboard. The LEDs
will dim and the LED current can be adjusted by varying the
analog voltage.
Open LED protection – Connect a voltage probe between
the VO+ terminal of any channel and GND and disconnect
V
I
LED
=
REF
± 3.0%the LED string. The output voltage will rise up to 92V and
(1)
4.99
trip the over voltage protection. At this point, all three chan-
nels will shut down and the output voltage of the channel
Current matching – Without changing the reference volt-with the open LED condition will be maintained hysteretically
age, enable each channel individually and measure the cur-between 92V and 82V until the output voltage of the fauly
rent (or, if possible, enable all channels and the three output channel falls below 82V or till the LED string is reconnected.
currents simultaneously). The error will be ≤ ± 3%.Once the LED string is reconnected, all three channels will
turn back on.
Linear Dimming – Vary the reference voltage between 0
– 500mV and measure the LED current. Short Circuit Protection – Short the output terminals of any
one channel using a jumper. All three channels shut down
The current will vary as per Eqn.1. This variation is fairly lin-and the IC tries restarting every 1.0ms. Once the short circuit
ear until the REF voltage gets very low. As the voltage goes is removed, all three channels come back into regulation.
below 50mV, the current will not match the reference voltage
as linearly.
PWM Dimming – With the reference voltage fixed at 0.5V,
apply a TTL compatible square wave signal (≤1kHz). The
LED current will dim based on the duty cycle of the PWM
input.
Doc.# DSDB-HV9982DB1
A032913
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Supertex inc.
HV9982DB1
Typical Results
Normal Operationboost converter and the parasitic capacitance at the drain
Fig.1 shows the waveforms during normal operation at full pin of the switching FET. This is a normal occurrence in any
load and 24V input. The smaller pulses in the drain wave-discontinuous mode converter.
forms represent the ringing between the input inductor of the
Fig. 1: Waveforms for Normal Operations
C1 (Yellow): Drain Waveform for Channel 1 (50V/div)
C2 (Pink): Drain Waveform for Channel 2 (50V/div)
C3 (Blue): Drain Waveform for Channel 3 (50V/div)
C4 (Green): Output Current for Channel 1 (100mA/div)
Time Scale: 1μs/div
Startup
Fig. 2 shows the startup waveforms. These waveforms were
obtained by connecting the PWMD pins to VDD and apply-
ing a step waveform at the 24V input. There is a 500μs delay
before the ramp voltage starts rising. This delay is due to the
time required to charge the capacitors at the VDD pins plus
the internal power-on-reset time. The other part of the delay
is the time required by the ramp capacitor to charge to 5V.
Once the RAMP voltage reaches 5V, the converter starts
switching and the LED current starts up slowly without any
overshoots.
Fig. 2: Startup Waveforms
C2 (Pink): RAMP waveform (2V/div)
C1 (Yellow): Input Voltage (10V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 500μs/div
Open LED Protection
Figs.3-6 show the over voltage protection in operation. Fig.
3 shows the open circuit condition occurring when the LED
current goes to zero. At this point, the output voltage starts
increasing since the energy from the input is used to charge
the output capacitors. Once the output voltage reaches 92V,
all three channels are shut down (Note: Output Voltage re-
fers to VO+ voltage GND). The hysteretic
over voltage protection is shown in Fig. 4 where the output
voltage is consistently maintained between 82V and 92V.
Fig. 3: Over Voltage Trigger
C1 (Yellow): Output Voltage of Channel 1 (20V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 20μs/div
Doc.# DSDB-HV9982DB1
A032913
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Supertex inc.
HV9982DB1
Fig. 4: Open LED Operation
C1 (Yellow): Output Voltage of Channel 1(20V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 20ms/div
The recovery from an open LED condition is shown in Fig. 5.
Two spikes are observed in the LED current. These spikes
are caused by the output capacitor discharging into the LEDs
since the capacitor voltage is higher the LED string voltage.
This causes the HV9982 to go into a hiccup mode short cir-
cuit condition till the capacitor voltage becomes lower than
the LED string voltage (as seen by the dip the output volt-
age). Once all fault conditions are cleared, the LED current
starts up smoothly into normal operation. Fig. 6 shows the
recovery with a smaller timescale.
Fig. 5: Recovery from Open LED Operation
C1 (Yellow): Output Voltage of Channel 1(20V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 20mA/div
Fig. 6: Recovery (smaller time scale)
C1 (Yellow): Output Voltage of Channel 1(20V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 500μs/div
Doc.# DSDB-HV9982DB1
A032913
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Supertex inc.
HV9982DB1
Short Circuit Protection
Figs. 7-9 show the operation of the short circuit protection.
Fig. 7 shows the response of the HV9982 to a short circuit
condition. The short circuit condition occurs when the output
current starts rising and the circuit shuts down in less than
200ns, providing a very fast response to an output short cir-
cuit (Note: LED string voltage refers to VO+ voltage mea-
its corresponding VO-).
The hiccup mode operation is shown in Fig. 8. The converter
tries to restart every 1ms and if the short circuit condition is
still detected, the converter shuts down.
The recovery from the short circuit condition is shown in Fig.
9. The LED current starts up without any overshoots.
Fig. 7: Waveforms for Normal Operations
C4 (Green): Output Current for Channel 1 (200mA/div)
Ma (Orange): LED String Voltage of Channel 1(20V/div)
Time Scale: 200ns/div
Fig. 8: Short Circuit Hiccup
C1 (Yellow): Output Voltage of Channel 1(20V/div)
C4 (Green): Output Current for Channel 1 (200mA/div)
Time Scale: 1ms/div
Fig. 9: Short Circuit Recovery
C1 (Yellow): Output Voltage of Channel 1(20V/div)
C4 (Green): Output Current for Channel 1 (200mA/div)
Time Scale: 500μs/div
Doc.# DSDB-HV9982DB1
A032913
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Supertex inc.
HV9982DB1
PWM Dimming Operation
PWM Dimming operation with an external TTL square wave
signal is shown in Figs. 10-12. Fig. 10 shows the overall op-
eration of the circuit with a PWM dimming input and Figs. 11
and 12 show the rise and fall times of the LED current during
PWM dimming.
In some cases, depending on the parasitic capacitance of
the LED string, there may be narrow spike in the LED cur-
rent during the rising edge. To prevent this spike from shut-
ting down the HV9982 due to a short circuit condition being
falsely detected, an internal 500ns blanking is provided in
the IC. Fig. 13 shows the rising edge of the PWM dimming
operation of the same LED driver with a different LED load
(which has a significant parasitic capacitance).
Fig. 10: PWM Dimming
C1 (Yellow): PWM Dimming Input for Channel 1(5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 500μs/div
Fig. 11: PWM Dimming – Rise Time
C1 (Yellow): PWM Dimming Input for Channel 1(5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 1μs/div
Fig. 12: PWM Dimming – Fall Time
C1 (Yellow): PWM Dimming Input for Channel 1(5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 1μs/div
Doc.# DSDB-HV9982DB1
A032913
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Supertex inc.
HV9982DB1
Fig. 13: Current Spike during PWM Dimming
C1 (Yellow): PWM Dimming Input for Channel 1(5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 500ns/div
Analog Control of PWM Dimming
The operation of the analog control of PWM dimming is
shown in Figs. 14-16. Fig. 14 shows the waveforms for op-
eration in one of the modes (S1=HI; S2=HI), with no external
SYNC signal applied. The plots in Figs. 15 and 16 show the
operation with an external 350Hz synchronizing clock. Fig.
15 shows the waveforms with S1=HI and S2=LO and Fig. 16
shows the waveforms with S1=HI and S2=HI. Fig. 17 shows
the variation of the average LED current with the voltage at
the PWMD pin in these modes of operation.
Fig. 14: Analog Control of PWM Dimming w/o external clock (S1 = HI and S2 = HI)
C3 (Blue): RAMP voltage (2V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 1ms/div
Fig. 15: Analog Control of PWM Dimming synchronized to external clock (S1 = HI and S2 = LO)
C2 (Pink): Signal at PWMD1 terminal (2V/div)
C3 (Blue): RAMP voltage (2V/div)
C1 (Yellow): External SYNC signal (5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 1ms/div
Fig. 16: Analog Control of PWM Dimming synchronized to external clock (S1 = HI and S2 = HI)
C2 (Pink): Signal at PWMD1 terminal (2V/div)
C3 (Blue): RAMP voltage (2V/div)
C1 (Yellow): External SYNC signal (5V/div)
C4 (Green): Output Current for Channel 1 (50mA/div)
Time Scale: 1ms/div
Doc.# DSDB-HV9982DB1
A032913
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Supertex inc.
HV9982DB1
Fig. 17: Analog Control of PWM Dimming - Measurements
120
Output Current vs. PWMD Voltage
100
L
E
D
C
u
r
r
e
n
t
(
m
A
)
80
60
S1 = HI
S2 = LO
S1 = HI
S2 = HI
40
20
0
-20
0 0.5 1.0 1.5 2
PWMD Voltage (V)
Circuit Schematic - Part 1 of 3
VIN
D1
DFLS1100-7
2
VIN
GND
GND1
C1
2.2µF
50V
C2
2.2µF
50V
R6
0.0
1/8W
VDD
VDD
1
L1
22µH
D2
VO+1
C3
0.33µF
100V
C4
0.33µF
100V
R1
845k
OVP1
D3
1N4148W
DFLS1100-7
0
C5
1.0µF
16V
R2
49.9k
VDD
U1A
8
0
9
C6
1.0µF
16V
11
0
C7
33nF
41
4
6
C8
1.0n
VIN
VDDA
GNDA
TH_PAD
COMP1
IREF1
GND1
1
HV9982
GATE1
CS1
FLT1
FDBK1
40
3
2
5
Q1
IRLM110A
VDD1
VO-1
R3
Q2
TN2510
0.27, 1/4W
REF
R4
1.0k
PWMD1OVP1
R5
4.99
1/8W
39 17 7
OVP1
C9
1.0n
0
F
PWMD1
IREF
Doc.# DSDB-HV9982DB1
A032913
9
Supertex inc.
HV9982DB1
Circuit Schematic - Part 2 of 3
VIN
C10
2.2µF
50V
1
D4
DFLS1100-7
2
L2
22µH
D5
VO+2
C1
0.33µF
100V
C12
0.33µF
100V
R9
845k
OVP2
D6
1N4148W
DFLS1100-7
VDD
VDD
F
C13
1.0µF
16V
EN
F
R10
100k
U1B
10
0
C14
2nF
C15
2nF
16
15
0
R13
1.0k
0
C17
1.0n
F
C16
33nF
12
13
EN
RAMP
GNDA
COMP2
IREF2
GND2
33
HV9982
GATE2
CS2
FLT2
FDBK2
35
37
36
38
Q3
IRLM110A
FF
R11
49.9k
F
VDD2
VO-2
R12
F
Q4
TN2510
SYNC
SKIP
0
0.27, 1/4W
Q7
R20
100k
IREF
PWMD2OVP2
R14
4.99
1/8W
34 18 14
F
OVP2
C18
1.0n
F
0
PWMD2
Circuit Schematic - Part 3 of 3
D7
DFLS1100-7
2
VIN
VDD
1
L3
22µH
D8
VO+3
VDD
0
VDD
0
C19
2.2µF
50V
DFLS1100-7
C20
0.33µF
100V
C21
0.33µF
100V
R15
845k
OVP3
D9
1N4148W
C22
1.0µF
16V
U1C
20
21
23
0
R18
1.0k
C24
1.0n
C23
33nF
27
25
S1
S2
CLK
COMP3
IREF3
GND3
33
HV9982
GATE3
CS3
FLT3
FDBK3
31
28
29
26
Q5
IRLM110A
VDD3
R16
49.9k
R17
VO-3
0.27, 1/4W
Q6
TN2510
IREF
PWMD3OVP3
R19
4.99
1/8W
32 19 24
PWMD3
C25
1.0n
OVP3
5.0V
C26
1.0µF
16V
1
2
OE
GND
VDD
OP
4
3
CLK
0
Doc.# DSDB-HV9982DB1
A032913
10
Supertex inc.
HV9982DB1
Bill of Materials
Item
Quan
#
120
RefDes
VO-1-3, VO+1-3,
PWMD1-3, GND,
GND1, VIN, VDD,
SKIP, REF, SYNC,
EN, CLK, 5V
C1,C2, C10,C19
C3,C4,
C11,C12,C20,C21
C5,C6, C13,C22,C26
C7,C16, C23
C8,C9,
C17,C18,C24,C25
C14,C15
D1,D2,D4,D5,D7,D8
D3,D6,D9
L1,L2,L3
Q1,Q3,Q5
Q2,Q4,Q6
Q7
R1,R9, R15
R2,R11, R16
R3,R12, R17
R4,R13, R18
R5,R14, R19
R6
R10,R20
SW1,SW2
U1
U2
DescriptionPackage
Manufac-
turer
Keystone
Electronics
Manufacturer’s
Part #
5016Compact surface mount test pointSMT
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
4
6
5
3
6
2
6
7
3
3
3
1
3
3
3
3
3
1
1
2
1
1
2.2µF, 50V, X7R ceramic chip
capacitor
0.33µF, 100V, metal film
capacitor
1µF, 16V, X7R ceramic
chip capacitor
33nF, 16V, X7R ceramic
chip capacitor
1nF, 50V, C0G ceramic
chip capacitor
2nF, 50V, C0G ceramic
chip capacitor
100V, 1A schottky diode
100V, 300mA switching diode
22uH, 1.2A rms, .5A sat inductor
100V, 0.44Ω, 1.5A N-channel
MOSFET
100V, 1.5Ω, N-channel MOSFET
30V, 1.6A N-channel MOSFET
845kΩ, 1/10W, 1% chip resistor
49.9kΩ, 1/10W, 1% chip resistor
0.27Ω, 1/4W, 5% chip resistor
1kΩ, 1/10W, 5% chip resistor
4.99Ω, 1/8W, 1% chip resistor
0.0Ω, 1/8W chip resistor
100kΩ, 1/10W, 1% chip resistor
SPDT Gull Wing slide switch
Three-channel closed-loop
LED Driver
6.176MHz fixed frequency
oscillator (optional)
SMD1206
Radial
SMD0603
SMD0603
SMD0603
SMD0603
Power
DI123
SOD-123
SMT
SOT-223
SOT-89
SOT-23
SMD0603
SMD0603
SMD1206
SMD0603
SMD0805
SMD0805
SMD0603
SMT
QFN-40
SMT
Murata
EPCOS Inc
Taiyo Yuden
Murata
Murata
Murata
Diodes Inc
Diodes Inc
Wurth
Electronik
Fairchild Semi
Supertex
Fairchild Semi
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Copal
Electronics Inc
Supertex
Citizen
America
GRM31CR71H225KA88L
B32521C1334J
EMK107BJ105KA-TR
GRM188R71C333KA01D
GRM1885C2A102JA01D
GRM1885C1H202JA01D
DFLS1100-7
1N4148W-7
744774122
IRLM110A
TN2510N8
NDS355N
---
---
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---
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---
---
CJS-1200TB
HV9982K6-G
CSX750PCC6.1760M-UT
Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives
an adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability
to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and
specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//)
©2013
Supertex inc.
All rights reserved. Unauthorized use or reproduction is prohibited.
Supertex inc.
11
Doc.# DSDB-HV9982DB1
A032913
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888