RT8800A

1

DS8800A-04 August 2007

www.richtek.com

All brand name or trademark belong to their owner respectively

Features

5V Power Supply Voltage

2/3-Phase Power Conversion with Automatic Phase

Selection

Output Voltage Controlled by External Reference

Voltage

Precise Core Voltage Regulation

Power Stage Thermal Balance by DCR Current

Sensing

Extreme Low-Cost, Lossless Time Sharing Current

Sensing

Internal Soft-Start

Hiccup Mode Over-Current Protection

Over-Voltage Protection

Adjustable Operating Frequency and Typical at

300kHz Per Phase

Power Good Indication

Small 16-Lead VQFN Package

RoHS Compliant and 100% Lead (Pb)-Free

Applications

Desktop CPU Core Power

Low Output Voltage, High Power Density DC-DC

Converters

Voltage Regulator Modules

General Purpose 3-Phase PWM Controller for High-Density

Power Supply

Ordering Information

Marking Information

For marking information, contact our sales representative

directly or through a Richtek distributor located in your

area, otherwise visit our website for detail.

Note :

Richtek Pb-free and Green products are :

RoHS compliant and compatible with the current require-

ments of IPC/JEDEC J-STD-020.

Suitable for use in SnPb or Pb-free soldering processes.

100% matte tin (Sn) plating.

General Description

The RT8800A is a general-purposed multi-phase

synchronous buck controller dedicating for high power

density applications. The RT8800A operates with 2 or 3

synchronous buck switching stages in interleaved phase

set automatically. The multiphase architecture provides

high output current while maintaining low power dissipation

on power devices and low stress on input and output

capacitors.

The output voltage is precisely regulated to the external

companioned with DAC generator RT9401A/B.

The RT8800A adopts innovative time-sharing DCR current

sensing technique for channel current balance, droop

tuning, and over current protection. Using one common

GM amplifier for current sensing eliminates offset errors

and linearity variation between GMs. As sub-milli-ohm-

grade inductors are widely used in modern mother boards,

slight mismatch of GM amplifiers offset and linearity results

in considerable current shift between phases. The time-

sharing DCR current sensing technique is extremely

important to guarantee phase current balance at mass

production.

Other features include overvoltage protection, undervoltage

protection and internal softstart. The RT8800A comes to

a VQFN-16L 3x3 package.

Package Type

QV : VQFN-16L 3x3 (V-Type)

Operating Temperature Range

P : Pb Free with Commercial Standard

G : Green (Halogen Free with Commer-

cial Standard)

RT8800A