LM3492HC Datasheet, PDF (3/17 Pages) Texas Instruments – Two-Channel Individual Dimmable LED Driver with Boost Converter and Fast Current Regulator

Pin Descriptions
Pin Name
Description
Application Information
1
EN Enable
Internally pull-up. Connect to a voltage higher than 1.63V to provide precision
enable for the device.
2
VIN Input Supply Voltage
Supply pin to the device. Input range is 4.5V to 65V.
3, 4
SW Switch Node
Internally connected to the drain of the integrated MOSFET.
5
VOUT Output Voltage Sense
Sense the output voltage for nearly constant switching frequency control.
6
RT Frequency Control
An external resistor from the VOUT pin to this pin sets the switching
frequency.
The output voltage is connected to this pin through a feedback resistor
7
FB Output Voltage Feedback
divider for output voltage regulation. The dynamic range of this pin is from
1.05V to 2.0V.
8
GND Analog Ground
Signal Ground
9
IOUT2
Current Regulator Input of Channel 2
Input of the current regulator of channel 2. The regulated current is
programmable (refer to the IREF pin).
10
IOUT1
Current Regulator Input of Channel 1
Input of the current regulator of channel 1. The regulated current is
programmable (refer to the IREF pin).
11 CDHC Dynamic Headroom Control
An external capacitor connected to this pin sets the DHC sensitivity. At
startup, a 120 µA internal current source charges an external capacitor to
provide a soft-start function.
12
IREF
Current Setting of the Current
Regulator
An external resistor connected from this pin to ground programs the
regulated current of the current regulator of channels 1 and 2.
This pin is open drain for various indications (power-good, over-temperature,
13 COMM Bi-directional Logic Communication IOUT over- and under-voltage) and command sending (switching frequency
tuning and channel 1 disabling).
14
LGND Ground of the Current Regulator
Current regulator ground. Must be connected to the GND pin for normal
operation. The LGND and GND pins are not internally connected.
15 DIM1/CLK Dimming Control of Channel 1
Control the on/off of the current regulator of channel 1. This pin is internally
pulled low by a 5 µA current. This pin also serves as a clock signal for latching
input/output data of the COMM pin.
16
DIM2 Dimming Control of Channel 2
Control the on/off of the current regulator of channel 2. This pin is internally
pulled low by a 5 µA current.
17, 18 PGND Power Ground
Integrated MOSFET ground. Must be connected to the GND pin for normal
operation. The PGND and GND pins are not internally connected.
19
VCC LDO Regulator Output
Nominally regulated to 5.5V. Connect a capacitor of larger than 0.47 µF
between the VCC and GND pins.
Connect an external resistor from the ILIM pin to the VCC pin reduces peak
20
ILIM Peak Current Limit Adjust
current limit. Connect the ILIM pin to the ground to obtain the maximum
current limit.
DAP DAP Exposed Pad
Thermal connection pad. Connect to a ground plane.
3
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