BD9132MUV_14 Datasheet, PDF (15/26 Pages) Rohm – Synchronous Buck Converter with Integrated FET

BD9132MUV
(5) Setting the Output Voltage
The output voltage VOUT is determined by equation (6):
V_OUT  R₂ / R₁ 1V_ADJ ・・・(6)
Where:
VADJ is the Voltage at ADJ terminal (0.8V Typ).
The required output voltage may be determined by adjusting R1 and R2.
Adjustable output voltage range: 0.8V to 3.3V
6
SW
1
ADJ
L
Co
Output
R2
R1
Figure 34. Setting the Output Voltage
Use 1 kΩ to 100 kΩ resistor for R1. If a resistor with resistance higher than 100 kΩ is used, check the circuit and
calculate carefully for ripple voltage etc.
3.7
The minimum input voltage depends on the output voltage.
Basically, it is recommended to use the condition below:
3.5
3.3
Vo=2.5V
V_CCMin V_OUT  1.2V
3.1
Vo=2.0V
Figure 35. Shows the necessary output current value for
minimum input voltage. (DCR of inductor : 20mΩ)
2.9
This data is just a characteristic value, so it’ doesn’t guarantee
the operation range.
2.7
0
Vo=1.8V
1
2
3
Output Current : IOUT[A]
7. BD9132MUV Cautions on PCB Layout
Figure 35. Minimum Input Voltage in each Output Voltage
Figure 36. Layout Diagram
(1) Layout the input ceramic capacitor CIN closer to the pins PVCC and PGND, and the output capacitor CO closer to
the pin PGND.
(2) Layout CITH and RITH between the pins ITH and GND as near as possible with least necessary wiring.
Note: VQFN020V4040 (BD9132MUV) has thermal PAD on the reverse of the package.
The package thermal performance may be enhanced by bonding the PAD to GND plane which occupies a large
area of PCB.
www.rohm.com
© 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
15/22
TSZ02201-0J3J0AJ00140-1-2
03.Oct.2014 Rev.002