(PDF) ADP1822 Datasheet, Controller

Data Sheet

PWM, Step-Down DC-to-DC Controller

with Margining and Tracking

ADP1822

FEATURES

Wide power input voltage range: 1 V to 24 V

Chip supply voltage range: 3.7 V to 5.5 V

Wide output voltage range: 0.6 V to 85% of input voltage

1% accuracy, 0.6 V reference voltage

Output voltage margining control

Output voltage tracking

All N-channel MOSFET

300 kHz, 600 kHz, or up to 1.2 MHz synchronized frequency

No current sense resistor required

Power-good output

Programmable soft start with reverse current protection

Current-limit protection

Thermal overload protection

Overvoltage protection

Undervoltage lockout

1 µA shutdown supply current

Small, 24-lead QSOP package

APPLICATIONS

Telecommunications and networking systems

High performance servers

Medical imaging systems

DSP core power supplies

Microprocessor core power supplies

Mobile communication base stations

Distributed power

GENERAL DESCRIPTION

The ADP1822 is a versatile and inexpensive synchronous voltage-

mode PWM step-down controller. It drives an all N-channel power

stage to regulate an output voltage as low as 0.6 V.

The ADP1822 regulated output can track another power supply

and can be dynamically adjusted up or down with the controller’s

margining-control inputs, making it ideal for high reliability

applications. It is well suited for a wide range of high power

applications, such as DSP power and processor core power in

telecommunications, medical imaging, high performance

servers, and industrial applications. It operates from a 3.7 V to

5.5 V supply with power input voltage ranging from 1.0 V to 24 V.

The ADP1822 can operate at any frequency between 300 kHz

and 1.2 MHz, either by synchronizing with an external source

or an internally generated, logic-controlled clock of 300 kHz or

600 kHz. It includes an adjustable soft start to allow sequencing

and quick power-up while preventing input inrush current. Output

reverse-current protection at startup prevents excessive output

voltage excursions. The adjustable, virtually lossless current-

limit scheme reduces external part count and improves efficiency.

The ADP1822 operates over the −40°C to +125°C junction

temperature range and is available in a 24-lead QSOP package.

3.3V OUTPUT

92 1.8V OUTPUT

0 2 4 6 8 10 12 14

LOAD CURRENT (A)

Figure 1. Efficiency vs. Load Current, 5 V Input

BIAS INPUT

1µF

15pF

80.6kΩ

309pF

CMOSH-3

10Ω

1µF

VCC PVCC BST

ADP1822 DH

SHDN

FREQ

SYNC

PWGD

CSL

PGND

MAR

MSEL

TRKP

TRKN

COMP

MDN

SS AGND DGND MUP

100nF

0.1µF

6.18kΩ

2.2pF

1nF

158kΩ

316kΩ

IRF3711

1µH

IRF3711

Figure 2. Typical Operating Circuit

180µF

20V

POWER INPUT

2.25V TO 24V

20kΩ

OUTPUT

1000µF 1.8V, 15A

10kΩ

TRACKING

SIGNAL INPUT

Rev. D

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other

rights of third parties that may result from its use. Specifications subject to change without notice. No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781.329.4700

www.analog.com

Part Number	ADP1822
Description	Step-Down DC-to-DC Controller
Manufacture	Analog Devices
Total Page	25 Pages
Datasheet	Download ADP1822 Datasheet

ADP1822 Controller Datasheet

ADP1822 Datasheet, PDF, Equivalent

ADP1822

Step-Down DC-to-DC Controller

Analog Devices