LTC3870-1

1

38701f

For more information www.linear.com/LTC3870-1

Typical applicaTion

FeaTures

DescripTion

PolyPhase Step-Down

Slave Controller for Digital

Power System Management

ler specially designed for multiphase operation with LTC's

digital power system management DC/DC controllers. It

provides a small and cost effective solution for supply-

ing very large currents by cascading it with a LTC3887-1

controller. A peak current mode architecture provides the

LTC3870-1 with excellent current sharing from phase to

phase and from chip to chip.

Coherently working with the LTC3887-1, the LTC3870-1

all programmable features as well as fault protection.

The constant switching frequency can be synchronized

to an external clock from the LTC3887-1 over a range of

100kHz to 1MHz.

Load Transient Response of a

2-Phase Master (3887-1)/Slave

(3870-1) Converter

applicaTions

n

LTC3887-1 Phase Extender

n

Operates with Power Blocks, DrMOS or External

Gate Drivers and MOSFETs

n

Cascade with Multiple Chips for Very Large Current

Applications

n

Accurate PolyPhase Current Sharing

n

n

n

Wide Output Voltage Range : 0.5V to 14V

n

Wide SYNC Frequency Range: 100kHz to 1MHz

n

Pin Programmable CCM/DCM Operation

n

Pin Programmable Phase-Shift Control

n

Available in a 24-Pin (4mm × 4mm) QFN Package

n

High Power Distributed Power Systems

n

Telecom Systems

n

Industrial Applications

L

, LT, LTC, LTM, PolyPhase, Linear Technology and the Linear logo are registered trademarks

of Linear Technology Corporation. All other trademarks are the property of their respective

owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6144194, 6177787,

6580258, 5408150

1.0µH

2.15k

0.2µF

0.56µH

1.74k

4.7µF

530µF

530µF

82.5k

DrMOS

DrMOS

RUN0

RUN1

FAULT0

FAULT1

SYNC

FREQ

PHASMD

MODE1

MODE0

GND

LTC3870-1

PWM0

PWM1

3.3V, 30A

7V TO 14V

RUN0

RUN1

GPIO0

GPIO1

SYNC

LTC3887-1

1.8V, 40A

3.3V

1.8V

* REFER TO LTC3887-1 DATA SHEET

FOR MASTER SETUP

38701 TA01a

0.2µF

22µF

100µs/DIV

20A/DIV

10A TO 20A TO 10A

(CH0)

10A/DIV

(CH0)

10A/DIV

200mV/DIV

AC–COUPLED

38701 TA01b