SM8172A Datasheet, PDF (6/17 Pages) Nippon Precision Circuits Inc – 2-output Power Supply IC

SM8172A
*2. The DC/DC converter output voltage (DCOUT) is determined by the external resistors as given by the following equation. The SM8172A DC/DC con-
verter controls the output to maintain the FB pin voltage of 0.6V.
Example settings
0.6 × (R1 + R2)
DCOUT =
R2
DCOUT [V]
0.8
R1 [kΩ]
200
R2 [kΩ]
600
C3 [pF]
8
1.000
200
300
8
1.200
200
200
8
1.502
200
133
8
DCOUT
LX
SM8172
C3
R1
FB
R2
1.800
200
100
The E-12 series usage example
DCOUT [V]
1.0
R1 [kΩ]
220
R2 [kΩ]
330
8
C3 [pF]
8
1.2
220
220
8
1.5
150
100
10
*3. The output voltage difference at I_DCO = 100mA and I_DCO = 900mA is within ± 3%.
I Accuracy of output voltage
The accuracy of DCOUT output voltage is affected by the FB pin voltage accuracy (0.6V ± 2%) and the exter-
nal resistor accuracy (R1, R2). If the external resistor of ± 1% accuracy is used, the accuracy of DCOUT output
voltage shows ± 3% accuracy including the FB pin voltage accuracy ± 2%.
SEIKO NPC CORPORATION —6