Synchronous, Step-Down DC-to-DC Controller with

Voltage Tracking and Synchronization

Data Sheet

ADP1853

Rev. 0

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FEATURES

Input voltage range: 2.75 V to 20 V

Output voltage range: 0.6 V to 90% V

IN

Maximum output current of more than 25 A

Current mode architecture with current sense input

Configurable to voltage mode

±1% output voltage accuracy over temperature

Voltage tracking input

Programmable frequency: 200 kHz to 1.5 MHz

Synchronization input

Internal clock output

Power saving mode at light load

Precision enable input

Power good with internal pull-up resistor

Adjustable soft start

Programmable current sense gain

Integrated bootstrap diode

Starts into a precharged load

Externally adjustable slope compensation

Suitable for any output capacitor

Overvoltage and overcurrent-limit protection

Thermal overload protection

Input undervoltage lockout (UVLO)

Available in 20-lead, 4 mm × 4 mm LFCSP

Supported by ADIsimPower™ design tool

APPLICATIONS

Intermediate bus and POL systems requiring sequencing and

tracking, including

Telecom base station and networking

Industrial and Instrumentation

Medical and healthcare

GENERAL DESCRIPTION

The ADP1853 is a wide range input, 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 nominally

operates in current mode with valley current sensing providing

the fastest step response for digital loads. It can also be

configured as a voltage mode controller with low noise and

crosstalk for sensitive loads.

The ADP1853 can be used as a master synchronization clock

for the power system and for convenient synchronization

between controllers. The CLKOUT signal can synchronize

other devices in the ADP185x family such that slave devices

are phase-shifted from the master to reduce the input ripple

current, improve EMI, and reduce the size of the input bulk

capacitance. The ADP1853 can also be configured as a slave

device for current sharing. Additionally, the ADP1853 includes

accurate tracking, precision enable, and power good functions

for sequencing. The ADP1853 provides a high speed, high peak

current gate driving capability to enable energy efficient power

conversion. The device can be configured to operate in power

saving mode by skipping pulses, reducing switching losses and

improving efficiency at light load and standby conditions.

The accurate current limit allows design within a narrower

range of tolerances and can reduce overall converter size and

cost. The ADP1853 can regulate down to 0.6 V output using a

high accuracy reference with ±1% tolerance over the

temperature range from −40°C to 125°C.

With a wide range input voltage, the ADP1853 is designed to

provide the designer with maximum flexibility for use in a

variety of system configurations; loop compensation, soft start,

frequency setting, power saving mode, current limit, and

current sense gain can all be programmed using external

components. In addition, the external RAMP resistor allows

and voltage mode for excellent line rejection. The linear

regulator and the boot strap diode for the high-side driver are

internal.

Protection features include undervoltage lock out, overvoltage,

overcurrent/short circuit, and overtemperature.

Figure 1. Typical Operation Circuit

VIN

M2

M1

FB

SW

PGND

VIN

L

DH

BST

DL

RAMP

PGOOD

SYNC

TRK

SS

ILIM

EN

COMP

CLKOUT

FREQ

VCCO

VOUT

ADP1853

HI

LO

CS

AGND