General Description

The RT8820A is a 2/1 phase synchronous Buck PWM

controller which is optimized for high performance graphic

microprocessor and computer applications. The IC

integrates a Constant-On-Time (COT) PWM controller, two

MOSFET drivers with internal bootstrap diodes, as well

as channel current balance and protection functions

including Over-Voltage Protection (OVP), Under-Voltage

Protection (UVP), current limit, and thermal shutdown into

the WQFN-20L 3x3 package.

The RT8820A adopts RDS(ON) current sensing technique.

Current limit is accomplished through continuous inductorcurrent-

sense, while RDS(ON) current sensing is used for

accurate channel current balance. Using the method of

current sampling utilizes the best advantages of each

technique.

The RT8820A features external reference input and PWMVID

dynamic output voltage control, in which the feedback

voltage is regulated and tracks external input reference

voltage. Other features include adjustable switching

frequency, dynamic phase number control, internal softstart,

power good indicator, and enable functions.

Features

 Dual-Phase PWM Controller

 Power State Indicator

 1P-CCM/2P-CCM/1P-DEM/2P-DEM

 Two Embedded MOSFET Drivers and Embedded

Switching Boot Diode

 Support 1.8V PWM-VID Interface

 External Reference Input Control

 PWM-VID Dynamic Voltage Control

 Dynamic Phase Number Control

 Lossless RDS(ON) Current Sensing for Current Balance

 Internal/External Soft-Start

 Adjustable Current Limit Threshold

 Adjustable Switching Frequency

 UVP/OVP Protection

 Shoot Through Protection and Short Pulse Free

Technology

 Support an Ultra-Low Output Voltage as Standby

Voltage

 Thermal Shutdown

 Power Good Indicator (EN to PG high = 500μs)

Applications

 CPU/GPU Core Power Supply

 Desktop PC Memory, VTT Power

 Chipset/RAM Power Supply

 Generic DC-DC Power Regulator