LD7120

2

Leadtrend Technology Corporation

LD7120-DS-05 February 2005

Pin Configuration

YY:

Year code

WW:

Week code

PP:

Production code

SOP-8 (TOP VIEW)

1

8

2

3

4

7

6

5

TOP MARK

YYWWPP

Ordering Information

Part number

Package

Top Mark

Shipping

LD7120 CS

SOP-8

LD7120CS

2500 /tape & reel

LD7120 PS

SOP-8 (PB Free)

LD7120PS

2500 /tape & reel

Pin Descriptions

PIN

NAME

FUNCTION

1

BOOT

This pin provides ground reference bias voltage to the upper MOSFET driver. Connect

this pin to a bootstrap circuit to pump a boot voltage to drive a N-channel MOSFET.

2

UGATE

Connect UGATE pin to the PWM converter’s upper MOSEFT gate. This pin provides

the gate drive for the upper MOSFET.

3

GND

Signal and power ground for the IC. All voltage levels are measured with respect to this

pin.

4

LGATE

Connect LGATE pin to the PWM converter’s lower MOSEFT gate. This pin provides the

gate drive for the lower MOSFET.

5

VCC

Connect this pin to 5V supply voltage. This pin provides the bias for the control circuitry

and the low side MOSFET driver. The voltage at this pin is monitored for Power-On

Reset (POR) purpose.

6

FB

This pin is the inverting input of the internal error amplifier. Connect this pin to the output

of the converter via an external resistor divider.

7

OCSET

Connect a resistor from this pin to the drain of the upper MOSFET. This resistor, internal

20μA current source, and upper MOSFET on resistance set the over current trip point.

8

PHASE

This pin is used to monitor the voltage drop across the upper MOSFET for over current

protection.