HV9982 Supertex, HV9982 Datasheet - Page 11

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

Pin Description
Pin #
10
12
13
14
15
16
17
18
19
20
21
11
1
2
3
4
5
6
7
8
9
PWMD1
PWMD2
PWMD3
COMP1
COMP2
FDBK1
RAMP
Name
VDD1
OVP1
OVP2
REF1
REF2
FLT1
SKIP
GND
VDD
CS1
VIN
EN
S1
S2
Supertex inc.
Description
Power supply pin for channel 1. 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 GND1 (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.
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 1. 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.
Stable closed loop control for channel 1 can be accomplished by connecting a compensation network
between each COMP1 pin and GND1.
Output current feedback input for channel 1. It receives a voltage signal from an external sense resis-
tor.
The voltage at this pin sets the output current level for channel 1. Recommended voltage range for
this pin is 0 – 1.25V.
Provides the over voltage protection for the channel 1. 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.
Input of the internal 40V linear regulator.
Output of the linear regulator. It maintains a regulated 7.75V as long as the voltage of the VIN pin is
between 10 and 40V. It must be bypassed with a low ESR capacitor to GND (at least 0.1μF). Can be
used as a power supply for the three channels.
When pin is pulled below 0.8V, the IC goes into a standby mode and draws minimal current.
Ground connection for the common circuitry in the HV9982.
Stable closed loop control for channel 2 can be accomplished by connecting a compensation network
between each COMP2 pin and GND2.
The voltage at this pin sets the output current level for channel 2. Recommended voltage range for
this pin is 0 – 1.25V.
Provides the over voltage protection for the channel 2. 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.
Programs the hiccup timer for fault conditions. A capacitor to GND programs the hiccup time.
Provides a ramp signal which is used while dimming the channels with pulse-width modulation with an
analog input. A capacitor to GND programs the PWM dimming frequency.
PWM dimming of the three channels is accomplished by using the PWMD pins. If S1 is LOW, then the
three pins directly control the PWM dimming of the three channels and a square wave input should be
applied at these pins. If S1 is high, then a 0 – 2.0V analog signal should be applied at these pins. The
PWM dimming is then done by comparing the analog voltage to the voltage at the RAMP pin.
Digital input pins which select the operating mode of the PWMD inputs. Refer to the PWM dimming
section for additional information.
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1235 Bordeaux Drive, Sunnyvale, CA 94089
11
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Tel: [phone]
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www.supertex.com
HV9982