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Rev. 1.11 - 2 -
n
BLOCK DIAGRAM
OSC
V
IN
EXT
GND
V
OUT
Vref
Vref
CE
Chip Enable
Soft Start
Protection
PWM/VFM
CONTROL
VD
OUT
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
a
Contents
Setting Output Voltage(V
OUT
):
Stepwise setting with a step of 0.1V in the range of 1.5V to 5.0V is possible.
Setting Detector Threshold(-V
DET
)
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
b
c