7/26/2019 Datasheet.hk_r2a20112_1756

1/12010. Renesas Electronics Corporation, All rights reserved.

Renesas Electronics URL http://www.renesas.com/pfcic

IL1

Gate

0A

Ave. Current

SINGLE

IL1+IL2

IL2

IL1

Gate1

Gate2

0A

Ave. Current

INTERLEAVE

FBFB

Downsizing boost coil, output

capacitor

Downsizing and simplification

of common filter and normal filter.

Efficiency up

Reduce line noise and radiation noise.

Reduce ripple

Downsizing boost coil(1) Downsizing filter

(3)Thermal balance on FET

(3)Reduce switching loss by ZCS, ZVS

1

FB

RT

OUT2

OUT1

ZCD2

OCP1

VREF

RAMP

OCP2 PGND

NC

NC

SGND

(2)Reduce recovery diode loss, changefrom expensive first recovery diode twocompetitive normal diode.

AC high voltageline less

(1)Reduceripple

Filter

Filter

Low standby current

Tolerance up

Total Cost Down!

Features

Low noise and Ripple reduction

GND bounce noise

Output ripple

Reducing input current ripple and GND bounce noise by interleaving technology.

Principle power loss reduction

DCM Single

CCM Single

Big loss

DCMInterleave

In CCM case, a peak current is small,

but switching loss is big at Ton.

To sift DCM interleave, it is possible to keep small loss at

Ton, and keep small peak current.

In DCM single case, switching loss is small,

but peak current is so large.

Small loss

FET current

Drain voltageBig peak current

Small peak current Small loss

Recovery loss of boost

diode by ZCS

Basically, no recovery

diode loss by sensing

zero current.

Improvement of thermal balance

Parallel swit ching by Single Mode Independent con trol by Interleave

(R2A20112)

Current

concentration by

different switching

timing.

Driver PFC

Current concentration point

FET1

FET2

FET3

FET1

FET2

PFC

Driver

Driver

Reduction of unbalance

by independent control.

Different of resister factor by each MOSFET

Improvement of load regulation by gm Amp

Error Amp

VREF

R2

R1

VOUT

VEO

Error AmpFB

VREF

R2

R1

VOUT

In case of gm Amp, there is no feedback current flow,

and load regulation becomes good.

Conventional R2A20112

Feedback loop detection

Built in over voltage protection. And feedback loop absence detection can stop

output pulse and PG signal. Therefore bulk capacitor and MOSFET are not broken if

using Renesas RFC IC.

PFC cut voltage

General IC

w/o this function

PFC cut voltage

Feedback loop i s down

case, bulk voltage isgoing up abnormal

voltage. Then

capacitor is broken.

R2A20112

The feedback loop

disconnection is detected,

and stop pulse!

Prevention from destruction of

bulk capacitor and power MOS!

cut cut

Conventional R2A20112

Dynamic OVP

200ms/div

20ms/div

O MP

Lm

V o u t

R2A20112 had Dynamic and Static OVP. Dynamic OVP is doing

discharge error Amp voltage before reaching Static OVP voltage. Therefore

peak current is limited. As the result, reduce over voltage cause No coil

vibration.

Reduce coil vibration when

change input voltage

suddenly by Dynamic OVP.

ZCS: Zero Current Switching

ZVS: Zero Voltage Switching

Renesas Low Noise & High Efficiency PFC Control IC

R2A20112 April 2010