Integrated, 4-Channel, High-Brightness LED

Driver with High-Voltage DC-DC Controller

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Pin Description (continued)

PIN

NAME

FUNCTION

TQFN

TSSOP

12

15

OUT2

LED String Cathode Connection 2. OUT2 is the open-drain output of the linear current sink that

controls the current through the LED string connected to OUT2. OUT2 sinks up to 150mA. If

unused, connect OUT2 to LEDGND.

13

16

LEDGND

LED Ground. LEDGND is the return path connection for the linear current sinks. Connect

SGND, LEDGND, and PGND at a single point.

14

17

OUT3

LED String Cathode Connection 3. OUT3 is the open-drain output of the linear current sink that

controls the current through the LED string connected to OUT3. OUT3 sinks up to 150mA. If

unused, connect OUT3 to LEDGND.

15

18

OUT4

LED String Cathode Connection 4. OUT4 is the open-drain output of the linear current sink that

controls the current through the LED string connected to OUT4. OUT4 sinks up to 150mA. If

unused, connect OUT4 to LEDGND.

16

19

CS

Current-Sense Input. CS is the current-sense input for the switching regulator. A sense resistor

connected from the source of the external power MOSFET to PGND sets the switching current

limit. A resistor connected between the source of the power MOSFET and CS sets the slope

compensation ramp rate (see the Slope Compensation section).

17

20

PGND

Power Ground. PGND is the switching current return path connection. Connect SGND,

LEDGND, and PGND at a single point.

18

1

NDRV

Switching n-MOSFET Gate-Driver Output. Connect NDRV to the gate of the external switching

power MOSFET.

19

2

DRV

MOSFET driver with the internal 5V regulator. Bypass DRV to PGND with a minimum of 0.1µF

ceramic capacitor.

20

3

as possible to the device.

—

—

EP

Exposed Pad. Connect EP to a large-area contiguous copper ground plane for effective power

dissipation. Do not use as the main IC ground connection. EP must be connected to SGND.