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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
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