BD8152FVM_1 Datasheet, PDF (12/18 Pages) Rohm – High-efficiency Step-up Switching Regulators with Built-in Power MOSFET

BD8152FVM, BD8158FVM
Technical Note
(2) When the output voltage is set to 0 V:
Since the switch does not exist between the input and output in the application using the step-up type DC/DC converter,
the output voltage is generated even if the IC is turned off. When it is intended to keep the output voltage 0 V until IC
operates, insert the switch as shown in the following circuit diagram.
1kΩ
D1
L1 10uH
RB161M-20
Vo
VCC
C1
10uF
C2
0.01uF
8
SS
SLOPE
+
SOFT
START
7
FCLK
OSC
6
VCC
5
SW
CURRENT
SENSE
Set _{LOGIC DRV}
Reset
SDW N
P+W_-M
OCP
E_- R+R
UVLO/TSD
1.245V
VREF
COMP
1
FB
2
ENB
3
GND
4
10uF
Switches of PNP or
PFET
R3
5.1kΩ
C3
3300pF
R1
110kΩ
R2
18kΩ
Fig. 31 Switch Application Circuit Diagram Example
Application Examples
(3) When the circuit is intended to operate at the lower voltage than the IC operating range:
Although the recommended operating range of IC starts from 2.5 V / 2.1 V (BD8152FVM,BD8158FVM), it is possible to
continue operating by composing the self-energizing type step-up DC/DC converter application even if the input
voltage lowered than 2.1 V. This example is recommended for the application with battery input.
L1 10uH
D1
RB161M-20
Vo
3.3V
VCC
2.0V
C1
10uF
C2
0.01uF
8
SS
SLOPE
+
SOFT
START
7
FCLK
OSC
6
VCC
5
SW
CURRENT
SENSE
Set _{LOGIC DRV}
Reset
SDW N
P+W_-M
OCP
E_- R+R
UVLO/TSD
1.245V
VREF
10uF
COMP
1
FB
2
ENB
3
GND
4
R3
5.1kΩ
R1
C3
3300pF
110kΩ
R2
18kΩ
Fig. 32 Self-Energizing Application Circuit Diagram Example
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12/17
2010.03 - Rev.B