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Date: 2/16/06

SP6134 Dual Supply, Synchronous Buck Controller

© Copyright 2006 Sipex Corporation

PIN #

PIN NAME DESCRIPTION

1

Bias Supply Input. Connect to external 5V supply. Used to power internal circuits and

low side gate driver.

2

GL

High current driver output for the low side NFET switch. It is always low if GH is high or

during a fault. Resistor pull down ensure low state at low voltage.

3

GND

Ground Pin. The control circuitry of the IC and lower power driver are referenced to this

4

Feedback Voltage and Short Circuit Detection pin. It is the inverting input of the Error

Amplifier and serves as the output voltage feedback point for the Buck Converter. The

output voltage is sensed and can be adjusted through an external resistor divider.

and the IC enters hiccup mode.

5

COMP

Output of the Error Amplifier. It is internally connected to the non-inverting input of the

PWM comparator. An optimal filter combination is chosen and connected to this pin and

6

UVIN

minimum operating voltage.

7

SS

Soft Start. Connect an external capacitor between SS and GND to set the soft start rate

based on the 10µA source current. The SS pin is held low via a 1mA (min) current during

all fault conditions.

8

SWN

Lower supply rail for the GH high-side gate driver. Connect this pin to the switching node

at the junction between the two external power MOSFET transistors.

9

GH

High current driver output for the high side NFET switch. It is always low if GL is high or

during a fault. Resistor pull down ensure low state at low voltage.

10

BST

High side driver supply pin. Connect BST to the external boost diode and capacitor as

shown in the Typical Application Circuit on page 1. High side driver is connected between

BST pin and SWN pin.

PIN DESCRIPTION