3A Bus Termination Regulator

Copyright

 ANPEC Electronics Corp.

Rev. A.8 - Oct., 2003

APL5331

www.anpec.com.tw

1

ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise

customers to obtain the latest version of relevant information to verify before placing orders.

•••••

Provide Bi-direction Current

•••••

1.25V/0.9V Output for DDR I/II Applications

•••••

Fast Transient Response

•••••

High Output Accuracy

- ±20mV over Load, VOUT Offset and

Temperature

••••• Adjustable Output Voltage by External Resistors

•••••

Current-Limit Protection

•••••

On-Chip Thermal Shutdown

•••••

Shutdown for Standby or Suspend Mode

•••••

Simple SOP-8, SOP-8-P with thermal pad,

TO-252- 5 and TO-263-5 Packages

Features

General Description (Cont.)

On-chip thermal shutdown provides protection against

any combination of overload that would create ex-

cessive junction temperature. The output voltage of

APL5331 track the voltage at VREF pin. A resistor

divider connected to VIN, GND and VREF pins is

used to provide a half voltage of VIN to VREF pin. In

addition, an external ceramic capacitor and an open-

drain transistor connected to VREF pin provides soft-

start and shutdown control respectively. Pulling and

holding the VREF to GND shuts off the output. The

output of APL5331 will be high impedance after be-

ing shut down by VREF or thermal shutdown function.

Applications

• DDR I/II SDRAM Termination

• SSTL-2/3 Termination Voltage

•

Applications Requiring the Regulator with









Pin Configuration

TO-252-5 (Top View)

VOUT

VREF

VCNTL

GND

VIN

TAB is VCNTL

TO-263-5 (Top View)

VIN

GND

VCNTL

VREF

VOUT

1

2

3

4

5

TAB is VCNTL

SOP-8 (Top View)

1

2

3

45

6

7

8

VIN

GN D

VR EF

VO U T

VC N TL

VC N TL

VC N TL

VCNTL

General Description

The APL5331 linear regulator is designed to provide

a regulated voltage with bi-directional output current

for DDR-SDRAM termination. The APL5331 integrates

two power transistors to source or sink current up to

3A. It also incorporate current-limit, thermal shut-

down and shutdown control functions into a single

chip. Current-limit circuit limits the short-circuit

current.

1

2

3

45

6

7

8

VIN

GND

VREF

VOUT

NC

VCNTL

NC

NC

SOP-8-P (Top View)

= Thermal Pad

NC = No internal connection

(connected to GND plane for better heat

dissipation)