AS1341
Datasheet - Application Information
9 Application Information
Adjusting Output Voltage
The AS1341 feedback input features dual-mode operation. Connect FB to GND for the 5.0V preset output voltage (see
Figure 21 on page 8). Adjust the output voltage by connecting a voltage-divider from the output to GND (see Figure
22).
Figure 22. Adjustable Output Voltage Circuit
VIN
4.5V to 20V
L1
1.25V to VIN
COUT
5
4
IN
7
LX
D1
+
CIN
RPULL
SHDNN
6
3
AS1341
R1
R2
POK
1
ILIMIT
FB
2
8
GND
OUT
Indicates High-Power Trace
Select a value for R2 between 10k and 1MΩ.
Calculate R1 as:
VOUT
VFB
⎛
⎞
--------------
R1 = R2 ⋅
– 1
(EQ 2)
⎝
⎠
Where:
VFB = 1.25V.
VOUT may range from 1.25V to VIN.
Negative Output Voltage
VIN may range from 4.5V to (20V-VOUT). Therefore the maximum negative output voltage is -15V.
Figure 23. Adjustable Negative Output Voltage Circuit
VIN
L1
4.5V to (20V-VOUT)
5
4
IN
7
LX
3
D1
R1
R2
POK
SHDNN
6
AS1341
1
+
COUT
CIN
FB
ILIMIT
8
2
OUT
GND
VOUT = -1.25V to -15V
Indicates High-Power Trace
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