1.5MHz, 30A High-Efficiency, LED Driver

with Rapid LED Current Pulsing

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7

Pin Description

PIN

NAME

FUNCTION

1

PGND

Power-Supply Ground

2, 7

N.C.

No Connection. Not internally connected.

3

DL

Low-Side Gate Driver Output

4

BST

Boost Flying Capacitor Connection. Reservoir capacitor connection for the high-side MOSFET driver

supply. Connect a ceramic capacitor between BST and LX.

5

LX

Source connection for the high-side MOSFET.

6

DH

High-Side Gate Driver Output. Drives the gate of the high-side MOSFET.

8, 22, 25

SGND

Signal Ground. Ground connection for the internal control circuitry. Connect SGND and PGND

together at one point near the IC.

9

CLKOUT

Oscillator Output. Rising edge of CLKOUT is phase-shifted from the rising edge of DH by 180°.

10

PGOOD

Power-Good Output

11

EN

Output Enable. Drive high or leave unconnected for normal operation. Drive low to shut down the

power drivers. EN has an internal 15µA pullup current. Connect a capacitor from EN to SGND to

program the hiccup-mode duty cycle.

12

RT/SYNC

Switching Frequency Programming and Chip-Enable Input. Connect a resistor from RT/SYNC to

SGND to set the internal oscillator frequency. Drive RT/SYNC to synchronize the switching frequency

with external clock.

13

V_IOUT

14

LIM

Current-Limit Setting Input. Connect a resistor from LIM to SGND to set the hiccup current-limit

threshold. Connect a capacitor from LIM to SGND to ignore short output overcurrent pulses.

15

OVI

Overvoltage Protection. Connect OVI to DIFF. When OVI exceeds 12.7% above the programmed

output voltage, DH is latched low and DL is latched high. Toggle EN or recycle the input power to

reset the latch.

16

CLP

Current-Error Amplifier Output. Compensate the current loop by connecting an RC network to ground.

17

EAOUT

Voltage-Error Amplifier Output. Connect to the external compensation network.

18

EAN

Voltage-Error Amplifier Inverting Input

19

DIFF

Differential Remote-Sense Amplifier Output. DIFF is the output of a precision unity-gain amplifier

whose inputs are SENSE+ and SENSE-.

20

CSN

Current-Sense Differential Amplifier Negative Input. The differential voltage between CSN and CSP is

amplified internally by the current-sense amplifier (gain = 34.5) to measure the inductor current.