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 built
in 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