n BLOCK DIAGRAM
OSC
VOUT
VIN
Vref
EXT
Protection
PWM/VFM
CONTROL
CE
Soft Start
Chip Enable
Vref
VDOUT
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
• • •
a b c
Code
Contents
a
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)
b
Stepwise setting with a step of 0.1V in the range of 1.2V to 4.5V is possible.
A:3.0V
c
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
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Rev. 1.11
- 2 -
RICOH [ RICOH ELECTRONICS DEVICES DIVISION ]
