Document
Preliminary Datasheet
R2A20124AFP/R2A20124ASP
R03DS0031EJ0300
Synchronous Phase Shift Full-Bridge Control IC Series
Rev.3.00 Mar 11, 2011
Description
The R2A20124AFP/R2A20124ASP controls a full-bridge phase shift circuit and secondary synchronous rectification. The R2A20124AFP/R2A20124ASP has adjustable delay time functions which make ZVS of primary side and make loss of body diode of primary switching device minimal.
The R2A20124AFP/R2A20124ASP is based on HA16163/R2A20121. And RAMP slope compensation circuit is builtin as an additional function. Also its output driver circuits are improved to enlarge gate drive output voltage swing from VREF to VCC.
In addition R2A20124AFP has ON/OFF function of synchronous rectification and includes amplifier which detect input current signal.
Features
Maximum ratings Supply voltage Vcc: 20 V Operating junction temperature Tj-opr: –40 to +125°C
Electrical characteristics VFB feedback voltage VFB(–): 1.25 V 2.0% UVLO (Under Voltage Lockout) operation start voltage VH: 8.4 V 0.7 V UVLO operation shutdown voltage VL: 8.0 V 0.6 V UVLO hysteresis voltage dVUVL: 0.4 V 0.1 V Output voltage swing of OUT-A, B, C, D, and E for gate drive: GND to VCC
Functions R2A20124AFP/R2A20124ASP Full-bridge phase-shift switching circuit with adjustable delay times Pulse by pulse current limit Synchronization I/O for the oscillator Ramp sloping adjustor Error amplifier built-in Soft start function
R2A20124AFP Synchronous rectification on/off control Remote on/off control Amplified output of current sense input voltage: CS
Package lineup Pb-free LQFP-40: R2A20124AFP Pb-free SOP-20: R2A20124ASP
Ordering Information
Part No. R2A20124AFP-W0 R2A20124AFP-W5 R2A20124AFP-U0 R2A20124AFP-U5 R2A20124ASP-W0 R2A20124ASP-W5 R2A20124ASP-U0 R2A20124ASP-U5
Package Name FP-40EV
FP-20DAV
Package Code PLQP0040JB-C
PRSP0020DD-B
Taping Spec. 2000 pcs./one taping product 2000 pcs./one taping product — — 2000 pcs./one taping product 2000 pcs./one taping product — —
R03DS0031EJ0300 Rev.3.00 Mar 11, 2011
Page 1 of 12
R2A20124AFP/R2A20124ASP
Modified Points from R2A20121SP
The swing level of the maximum output voltage is changed from VREF to VCC. Ramp sloping compensation circuit is added. Synchronous rectification control is possible to turned off at light load. (only R2A20124AFP) On/off control terminal for Remote is added. (only R2A20124AFP)
Illustrative Circuit
Preliminary
VIN
DC 12 V
DC 12 V
DC 12 V
DC 12 V
DC 12 V
Vbias (DC 12 V)
VCC OUT OUT CS RAMP RAMP OUT OUT
-A -B
-SLP -C -D
SEC-CONT(∗1)
REMOTE(∗1) R2A20124AFP/ASP
VREF
OUT OUT -E -F COMP
FB(–)
CS- DELAY DELAY DELAY
PGND SGND RT SYNC SS OUT(∗1) -1
-2
-3
Note: ∗1. Only R2A20124AFP
R03DS0031EJ0300 Rev.3.00 Mar 11, 2011
Page 2 of 12
R2A20124AFP/R2A20124ASP
Pin Arrangement
R2A20124AFP
Preliminary
N.C. RAMP-SLP N.C. SYNC N.C. N.C. RT SGND PGND N.C.
RAMP N.C. CS
CS-OUT N.C.
COMP FB(–)
SS N.C. N.C.
30 29 28 27.