LM5025

UVLO

PGND AGND

COMP

OUT_A

OUT_B

SS

Rt

SYNC

REF

TIME

RAMP

CS1

CS2

35 - 78V

3.3V

UP/DOWN

SYNC

ERROR

AMP &

ISOLATION

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LM5025

SNVS265C – DECEMBER 2003 – REVISED JANUARY 2016

LM5025 Active Clamp Voltage Mode PWM Controller

1 Features

3 Description

The LM5025 PWM controller contains all of the

1

•

Internal Start-Up Bias Regulator

features necessary to implement power converters

•

3-A Compound Main Gate Driver

using the active clamp and reset technique. The

•

Programmable Line Undervoltage Lockout (UVLO)

device can be configured to control either a

With Adjustable Hysteresis

P-channel clamp switch or an N-channel clamp

switch. With the active clamp technique, higher

•

Voltage Mode Control With Feed-Forward

efficiencies and greater power densities can be

•

Adjustable Dual-Mode Overcurrent Protection

realized compared to conventional catch winding or

•

Programmable Overlap or Deadtime Between the

RDC clamp and reset techniques.

Main and Active Clamp Outputs

Two control outputs are provided, the main power

•

Volt × Second Clamp

switch control (OUT_A), and the active clamp switch

•

Programmable Soft-Start

control (OUT_B). The active clamp output can be

configured for either a specified overlap time

•

Leading Edge Blanking

(for P-channel switch applications) or a specified

•

Single Resistor Programmable Oscillator

deadtime (for N_channel applications). The two

•

Oscillator UP and DOWN Sync Capability

internal compound gate drivers parallel both MOS

•

Precision 5-V Reference

and bipolar devices, providing superior gate drive

characteristics. This controller is designed for high-

•

Thermal Shutdown

speed operation including an oscillator frequency

range up to 1 MHz and total PWM and current sense

2 Applications

propagation delays less than 100 ns.

•

Server Power Supplies

The

LM5025

includes

a

high-voltage

start-up

•

48-V Telecom Power Supplies

regulator that operates over a wide input range of

•

42-V Automotive Applications

13 V to 90 V. Additional features include: line

undervoltage lockout (UVLO), soft-start, oscillator UP

•

High-Efficiency DC-to-DC Power Supplies

and DOWN sync capability, precision reference and

thermal shutdown.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

TSSOP (16)

5.00 mm × 4.40 mm

LM5025

WSON (16)

5 00 mm × 5.00 mm

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Simplified Schematic

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.