R1234D Datasheet, PDF (2/26 Pages) RICOH electronics devices division – PWM/VFM Step-Down DC/DC CONVERTER with Synchronous Rectifier

R1234D
BLOCK DIAGRAM
R1234Dxx1A/B
VDD
MODE
3
6
“L” PWM “H” VFM
1 ^VIN
Lx ₈
PWM/VFM
CONTROL
OUTPUT
CONTROL
Current Protection
OSC
Phase Comp.
5 ^VOUT
Vref
CE
UVLO
Soft Start
Chip Enable
“H” Active
4 ^CE
2
PGND
7
AGND
1 VIN
Lx ₈
R1234Dxx1C/D
VDD
MODE
3
6
“L” PWM “H” VFM
PWM/VFM
CONTROL
OUTPUT
CONTROL
Current Limit
OSC
Phase Comp.
5 ^VFB
UVLO
Vref
Chip Enable
Soft Start
“H” Active
4 ^CE
2
PGND
7
AGND
2