RT8128A/C

2

DS8128A/C-03

March 2016

www.richtek.com

©

Copyright

2016 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Functional Pin Description

Ordering Information

Note :

Richtek products are :

ments of IPC/JEDEC J-STD-020.

Pin Configurations

(TOP VIEW)

SOP-8 (Exposed Pad)

Marking Information

Pin No.

Pin Name

Pin Function

1

BOOT

Bootstrap Supply for High-Side Gate Driver. Connect a capacitor between the

BOOT and PHASE pins.

2

UGATE

Gate Drive Output for the High-Side External MOSFET.

3

PGOOD

Open-Drain Power Good Indicator. High impedance indicates power is good.

4

LGATE/OCSET

Gate Drive Output for the Low-Side External MOSFET. This pin is also used

to set the OCP threshold. Please refer the application information.

5

VCC

Control Voltage Input. It supports the power for the PWM controller, the

low-side driver and the bootstrap circuit for high-side driver. Bypass to GND

with a 4.7

F ceramic capacitor.

6

FB

Feedback Voltage Input. Connect FB and GND to a resistive voltage divider

to set the output voltage level. The internal reference voltage is 0.6V typically.

7

EN

Active-High Enable Control Input. Pull low to GND to disable the PWM

controller.

8

PHASE

Return Path of High-Side Gate Driver. Connect this pin to external MOSFETs

and inductor. It behaves as the current sense comparator input for low-side

9 (Exposed pad) GND

Ground. Connect this pin directly to the low-side MOSFET source and ground

plane with the lowest impedance. The exposed pad must be soldered to a

large PCB and connected to GND for maximum power dissipation.

RT8128xGSP : Product Number

x : A or C

YMDNN : Date Code

RT8128x

GSPYMDNN

BOOT

UGATE

PGOOD

LGATE/OCSET

PHASE

EN

VCC

FB

GND

2

3

4

5

6

7

8

9

RT8128A/C

Package Type

SP : SOP-8 (Exposed Pad-Option 1)

Lead Plating System

G : Green (Halogen Free and Pb Free)

A : Diode Emulation Mode

C : FCCM