BD9152MUV Datasheet, PDF (13/18 Pages) Rohm – Output 1.5A or Less High Efficiency Step-down Switching Regulator with Built-in Power MOSFET

BD9152MUV
Technical Note
RITH1
CITH1
RITH2
CITH2
L1
FB1 EN1 SW1 SW1 PGND1
ITH1
PGND1
AGND
N.C.
AVcc
PVcc
PVcc
PVcc
ITH2
PGND2
FB2 EN2 SW2 SW2 PGND2
ESR
COUT1
VOUT1
RO1
CIN1
CIN2
COUT2
VOUT2
L2
R2 _RO2
R1
Fig.38 Typical application
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.
fz(Amp.)= fp(Min.)
1
2π×RITH×CITH
=
1
2π×ROMax.×CO
5. Determination of VOUT2 output voltage
The output voltage VOUT2 is determined by the equation (6):
VOUT2=(R2/R1+1)×VFB2・・・(6) VFB2: Voltage at ADJ terminal (0.8V Typ.)
With R1 and R2 adjusted, the output voltage may be determined as required.
L2
SW2
Cout2
VOUT2
R2
Adjustable output voltage range : 0.8V～2.5V
FB2
R1
Fig.39 Determination of output voltage
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.
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13/17
2009.05 - Rev.A