Wide Range Input, Dual/Two-Phase, DC-to-DC

Synchronous Buck Controller

Data Sheet

ADP1850

Rev. C

Document Feedback

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

responsibilityisassumedbyAnalogDevicesforitsuse,norforanyinfringementsofpatentsorother

rightsofthirdpartiesthatmayresultfromitsuse.Specificationssubjecttochangewithoutnotice.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

©2010–2017 Analog Devices, Inc. All rights reserved.

Technical Support

www.analog.com

FEATURES

Wide range input: 2.75 V to 20 V

Power stage input voltage: 1 V to 20 V

Output voltage range: 0.6 V up to 90% V

IN

Output current to more than 25 A per channel

Accurate current sharing between channels (interleaved)

Programmable frequency: 200 kHz to 1.5 MHz

180° phase shift between channels for reduced input

capacitance

±0.85% reference voltage accuracy from −40°C to +85°C

Integrated boost diodes

Power saving mode (PSM) at light loads

Accurate power good with internal pull-up resistor

Accurate voltage tracking capability

Independent channel precision enable

Overvoltage and overcurrent limit protection

Externally programmable soft start, slope compensation and

current sense gain

Synchronization input

Thermal overload protection

Input undervoltage lockout (UVLO)

Available in 32-lead 5 mm × 5 mm LFCSP

APPLICATIONS

High current single and dual output intermediate bus and

point of load converters requiring sequencing and

tracking capability, including converters for:

Point-of-load power supplies

Telecom base station and networking

Consumer

Industrial and instrumentation

Healthcare and medical

GENERAL DESCRIPTION

The ADP1850 is a configurable dual output or two-phase, single

output dc-to-dc synchronous buck controller capable of running

from commonly used 3.3 V to 12 V (up to 20 V) voltage inputs.

The device operates in current mode for improved transient

response and uses valley current sensing for enhanced noise

immunity.

The architecture enables accurate current sharing between

interleaved phases for high current outputs.

The ADP1850 is ideal in system applications requiring multiple

output voltages: the ADP1850 includes a synchronization fea-

ture to eliminate beat frequencies between switching devices;

provides accurate tracking capability between supplies and

includes precision enable for simple, robust sequencing.

TYPICAL OPERATION CIRCUIT

RAMP1

VIN

DH1

BST1

SW1

ILIM1

FB1

DL1

PGND1

RAMP2

DH2

BST2

SW2

ILIM2

FB2

DL2

PGND2

EN1

EN2

VDL

VCCO

TRK1

TRK2

SYNC

FREQ

COMP1

COMP2

SS1

SS2

AGND

R11

R12

R21

R22

M1

M2

M3

L2

L1

M4

PGOOD1

PGOOD2

ADP1850

HI

LO

Figure 1. Single Phase Circuit

The ADP1850 provides high speed, high peak current drive

capability with dead-time optimization to enable energy

efficient power conversion. For low load operation, the device

can be configured to operate in power saving mode (PSM) by

skipping pulses and reducing switching losses to improve the

energy efficiency at light load and standby conditions.

The accurate current limit (±6%) allows the power architect to

design within a narrower range of tolerances and can reduce

overall converter size and cost.

The ADP1850 provides a configurable architecture capable

of wide range input operation to provide the designer with

maximum re-use opportunities and improved time to market.

Additional flexibility is provided by external programmability

of loop compensation, soft start, frequency setting, power

saving mode, current limit and current sense gain can all be

programmed using external components.

The ADP1850 includes a high level of integration in a small size

package. The start-up linear regulator and the boot-strap diode

for the high side drive are included. Protection features include:

undervoltage lock-out, overvoltage, overcurrent/short-circuit

and over temperature. The ADP1850 is available in a compact

32-lead LFCSP 5 mm × 5 mm thermally enhanced package.