Data Sheet
AC4790
Datasheet
https://www.lairdconnect.com/
29
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13 APPENDIX II: SAMPLE POWER SUPPLY
This appendix describes a simple switching power supply that provides enough current to easily power any Laird OEM module.
It utilizes low cost, off-the-shelf components that fit into a small area. This supply has an input voltage range of +6 volts to +18
volts and outputs +3.4 volts at 1.5 amps.
Included is a schematic, bill of materials with manufacture's name and part numbers, and a sample PCB layout. It is important
to follow the layout suggestions and use large areas of copper to connect the devices as shown in the layout. It is also
important to hook up the ground traces as shown and use multiple vias to connect input and output capacitors to the bottom
side ground plane.
If the input voltage is fewer than 12 volts then C1 and C2 can be replaced with a single 100 uF 20 volt capacitor (same part
number as C7). This reduces board space and lowers costs further. If you are powering an AC5124 module, R1 can be
changed to a 373 ohm 1% resistor. This changes the output to +5 volts at 1.0 amps.
13.1 Bill of Materials
Table 11: Power Supply Bill of Materials
Qty
Reference
Value
Description
Mfg.
Mfg. part number
1
R1
210
Res, 0603, 210, 1/16W, 1%
KOA
RK73H1JT2100F
1
R2
127
Res, 0603, 127, 1/16W, 1%
KOA
RK73H1JT1270F
2
C1 C2
47uF
Cap, Tant, 7343, 47uF, 35V
AVX
TPSE476M035R0200
3
C3 C4 C5
0.1 uF
Cap, Cer, 0603, 0.1uF, Y5V, 25V
Murata
GRM39Y5V104Z025AD
1
C6
3300 pF
Cap, Cer, 0603, 3300pF, X7R, 50V
Murata
GRM39X7R332K050AD
1
C7
100 uF
Cap, Tant, 7343, 100uF, 20V
Kemet
T491X107K020A5
1
D1
B230/A
Diode, SMB, B230/A, 2A, Schottkey
Diodes, Inc.
B230/A
1
D2
LL4148
Diode, MELF, LL4148, Switch Diode
Diodes, Inc.
LL4148
1
L1
15 uH
Xfmr, 2P, SMT, 15uH, 2A
Coiltronics
UP2.8B150
1
U1
CS51413
IC, CS51413, 8P, SO, Switch Reg Ctrl
On-Semicond
CS51413