ML4804CS Micro Linear, ML4804CS Datasheet

ML4804CS

Manufacturer Part Number

ML4804CS

Description

Power Factor Correction and PWM Controller Combo

Manufacturer

Micro Linear

Datasheet

1.ML4804CS.pdf (14 pages)

Current page: 1 of 14
Download datasheet (247Kb)

GENERAL DESCRIPTION

The ML4804 is a controller for power factor corrected,

switched mode power supplies. Power Factor Correction

(PFC) allows the use of smaller, lower cost bulk

capacitors, reduces power line loading and stress on the

switching FETs, and results in a power supply that fully

complies with IEC1000-3-2 specification. Intended as a

BiCMOS enhancement of the industry-standard ML4824,

the ML4804 includes circuits for the implementation of

leading edge, average current, “boost” type power factor

correction and a trailing edge, pulse width modulator

(PWM). It also includes a TriFault Detect™ function to

help ensure that no unsafe conditions will result from

single component failure in the PFC. 1A gate-drive

outputs minimize the need for external driver circuits.

Low power requirements improve efficiency and reduce

component costs.

An over voltage comparator shuts down the PFC section

in the event of a sudden decrease in load. The PFC

section also includes peak current limiting and input

voltage brownout protection. The PWM section can be

operated in current or voltage mode, at up to 250kHz,

and includes an accurate 50% duty cycle limit to prevent

transformer saturation.

BLOCK DIAGRAM

Power Factor Correction and PWM Controller Combo

I AC

V FB

V RMS

I SENSE

RAMP 1

RAMP 2

V DC

DC I LIMIT

2.5V

V CC

25µA

VEA

V REF

VEAO

MODULATOR

1.25V

GAIN

1.6k

IEA

IEAO

OSCILLATOR

0.5V

2.45V

V FB

POWER FACTOR CORRECTOR

16.4V

PULSE WIDTH MODULATOR

V CC

–

TRI-FAULT

–

V CC OVP

V IN OK

DUTY CYCLE

LIMIT

FEATURES

1.0V

2.75V

Internally synchronized leading-edge modulated PFC

and trailing-edge modulated PWM in one IC

TriFault Detect

enhanced safety

Slew rate enhanced transconductance error amplifier

for ultra-fast PFC response

Low power: 200µA startup current, 5.5mA operating

current

Low total harmonic distortion, high PF

Reduces ripple current in the storage capacitor

between the PFC and PWM sections

Average current, continuous boost leading edge PFC

PWM configurable for current-mode or voltage mode

operation

Overvoltage and brown-out protection, UVLO, and soft

start

-1V

OVP provides additonal PFC fault protection

PFC I LIMIT

OVP

DC I LIMIT

V CC

for UL1950 compliance and

V CC

17V

UVLO

REFERENCE

7.5V

V CC

PWM OUT

PFC OUT

ML4804

V REF

PRELIMINARY

May 1999

Related parts for ML4804CS

Related keywords

ML4804CS datasheet
ML4804CS data sheet
ML4804CS pdf datasheet
ML4804CS component
ML4804CS part
ML4804CS distributor
ML4804CS RoHS
ML4804CS datasheet download