HV9982 Supertex, HV9982 Datasheet - Page 12

• Manufacturer Part Number: HV9982
• Description: LED Drivers 3-Channel LED High Accuracy
• Manufacturer: Supertex

Pin Description
Pin #
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
COMP3
FDBK3
FDBK2
GATE3
GATE2
GATE1
GND3
GND2
GND1
Name
OVP3
VDD3
VDD2
REF3
FLT3
FLT2
CLK
CS3
CS2
NC
Supertex inc.
Description
No connect.
Clock input for the HV9982. The input to the CLK pin should be a TTL compatible square wave signal.
The three channels will switch at 1/12
Provides the over voltage protection for the channel 3. When the voltage at this pin exceeds 5.0V, the
HV9982 is turned off and the fault timer starts. Upon completion of the fault timer the IC attempts to
restart.
The voltage at this pin sets the output current level for channel 3. Recommended voltage range for
this pin is 0 – 1.25V.
Output current feedback input for channel 3. It receives a voltage signal from an external sense resis-
tor.
Stable closed loop control for channel 3 can be accomplished by connecting a compensation network
between each COMP3 pin and GND3.
Used to sense the source current of the external power FET used with channel 3. It includes a built-in
100ns (min) blanking timer. An R-C network at this pin programs the slope compensation. Refer to the
Slope Compensation section for additional information.
Used to drive an external disconnect switch. The disconnect switch is used to protect the LEDs in case
of fault conditions and also help to provide excellent PWM dimming response by disconnecting and
reconnecting the LEDs from the output capacitor during PWM dimming.
Power supply pin for channel 3. It can either be connected to the VDD pin or supplied with an external
power supply. It must be bypassed with a low ESR capacitor to GND3 (at least 0.1μF). All VDD pins
(VDD, VDD1-3) must be connected together externally. An external supply (7.0 – 9.0V) can be con-
nected to these pins to power the IC if the internal regulator is not used.
Output gate drive for an external N-channel power MOSFET.
Ground return for channel 3. It is recommended that all the GNDs of the IC be connected together in
a STAR connection at the input GND terminal to ensure best performance.
Power supply pin for channel 2. It can either be connected to the VDD pin or supplied with an external
power supply. It must be bypassed with a low ESR capacitor to GND2 (at least 0.1μF). All VDD pins
(VDD, VDD1-3) must be connected together externally. An external supply (7.0 – 9.0V) can be con-
nected to these pins to power the IC if the internal regulator is not used.
Ground return for channel 2. It is recommended that all the GNDs of the IC be connected together in
a STAR connection at the input GND terminal to ensure best performance.
Output gate drive for an external N-channel power MOSFET.
Used to drive an external disconnect switch. The disconnect switch is used to protect the LEDs in case
of fault conditions and also help to provide excellent PWM dimming response by disconnecting and
reconnecting the LEDs from the output capacitor during PWM dimming.
Used to sense the source current of the external power FET used with channel 2. It includes a built-in
100ns (min) blanking timer. An R-C network at this pin programs the slope compensation. Refer to the
Slope Compensation section for additional information.
Output current feedback input for channel 2. It receives a voltage signal from an external sense resis-
tor.
Ground return for channel 1. It is recommended that all the GNDs of the IC be connected together in
a STAR connection at the input GND terminal to ensure best performance.
Output gate drive for an external N-channel power MOSFET.
(cont.)
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1235 Bordeaux Drive, Sunnyvale, CA 94089
th
the switching frequency of the signal applied at the CLK pin.
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Tel: [phone]
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www.supertex.com
HV9982