R1221N Datasheet, PDF (2/21 Pages) RICOH electronics devices division – Step-down DC/DC Converter with Voltage Detector

n BLOCK DIAGRAM
OSC
VIN
EXT
PWM/VFM
CONTROL
Vref
Protection
Soft Start
Chip Enable
Vref
VDOUT
VOUT
CE
GND
n SELECTION GUIDE
In the R1221N Series, the output voltage, the detector threshold, the oscillator frequency, the optional
function, and the taping type for the ICs can be selected at the user’s request.
The selection can be made by designating the part number as shown below;
R1221NXXXX-TR
- --
Code
a
b
c
a bc
Contents
Setting Output Voltage(VOUT):
Stepwise setting with a step of 0.1V in the range of 1.5V to 5.0V is possible.
Setting Detector Threshold(-VDET)
Stepwise setting with a step of 0.1V in the range of 1.2V to 4.5V is possible.
A:3.0V
Designation of Oscillator Frequency and Optional Function
A:300kHz, with a PWM/VFM alternative circuit, Latch-type protection
B:500kHz, with a PWM/VFM alternative circuit, Latch-type protection
C:300kHz, without a PWM/VFM alternative circuit, Latch-type protection
D:500kHz, without a PWM/VFM alternative circuit, Latch-type protection
E:300kHz, with a PWM/VFM alternative circuit, Reset-type protection
F:500kHz, with a PWM/VFM alternative circuit, Reset-type protection
G:300kHz, without a PWM/VFM alternative circuit, Reset-type protection
H:500kHz, without a PWM/VFM alternative circuit, Reset-type protection
12345
Rev. 1.11
-2-