bd9132muv ROHM Co. Ltd., bd9132muv Datasheet - Page 11

• Manufacturer Part Number: bd9132muv
• Description: Step-down Switching Regulator
• Manufacturer: ROHM Co. Ltd.

Stable feedback loop may be achieved by canceling the pole fp (Min.) produced by the output capacitor and the load resistance
with CR zero correction by the error amplifier.
5. Determination of output voltage
V
The output voltage V
V
With R1 and R2 adjusted, the output voltage may be determined as required.
The lower limit of input voltage depends on the output voltage.
Basically, it is recommended to use in the condition :
Fig.34. shows the necessary output current value at the lower
limit of input voltage. (DCR of inductor : 20mΩ)
This data is the characteristic value, so it’ doesn’t guarantee the
operation range,
Use 1 kΩ～100 kΩ resistor for R1. If a resistor of the resistance higher than 100 kΩ is used, check the assembled set carefully
for ripple voltage etc.
CC
OUT
V
=(R2/R1+1)×V
CCmin
fz
Adjustable output voltage range : 0.8V～2.5V
(Amp.)
V
R
C
Cin
OUT
= V
ITH
ITH
= fp
OUT
2π×R
(Min.)
+1.2V.
OUT
ADJ
EN
ADJ
ITH
ITH
・・・(6) V
1
Fig.32 Typical application
is determined by the equation (6):
×C
ITH
PV
GND,PGND
CC
=
ADJ
R
f
: Voltage at ADJ terminal (0.8V Typ.)
2π×R
V
CC
SW
OMax.
1
C
×C
f
C
O
BST
11/15
L
ESR
C
O
R
Fig.34 minimum input voltage in each output voltage
O
3.7
3.5
3.3
3.1
2.9
2.7
V
OUT
0
Fig.33 Determination of output voltage
1
6
SW
ADJ
Vo=2.5V
OUTPUT CURRENT : IOUT[A]
1
L
Vo=2.0V
Co
2
R2
R1
Vo=1.8V
Output
3