4

Package Pin Description

PACKAGE PIN #

PIN SYMBOL

FUNCTION

16L SO Narrow & PDIP

1,2,3,4

Voltage ID DAC input pins. These pins are internally pulled up to 5V

providing logic ones if left open. The DAC range is 2.14V to 3.54V with

Leaving all 4 DAC input pins open results in a DAC output voltage of

1.244V, allowing for adjustable output voltage, using a traditional resis-

tor divider.

5

SS

Soft Start Pin. A capacitor from this pin to LGnd in conjunction with

internal 60µA current source provides soft start function for the con-

troller. This pin disables fault detect function during Soft Start. When a

fault is detected, the soft start capacitor is slowly discharged by internal

2µA current source setting the time out before trying to restart the IC.

Charge/discharge current ratio of 30 sets the duty cycle for the IC when

the regulator output is shorted.

6, 12

NC

No connection.

A capacitor from this pin to ground sets the time duration for the on

board one shot, which is used for the constant off time architecture.

Fast feedback connection to the PWM comparator. This pin is connected

to the regulator output. The inner feedback loop terminates on time.

Boosted power for the gate driver.

10

MOSFET driver pin capable of 1.5A peak switching current.

11

PGnd

High current ground for the IC. The MOSFET driver is referenced to this

pin. Input capacitor ground and the anode of the Schottky diode should

be tied to this pin.

13

Input power for the IC.

14

LGnd

Signal ground for the IC. All control circuits are referenced to this pin.

15

COMP

Error amplifier compensation pin. A capacitor to ground should be pro-

vided externally to compensate the amplifier.

16

Error amplifier DC feedback input. This is the master voltage feedback

which sets the output voltage. This pin can be connected directly to the

output or a remote sense trace.