Power Supply - Mikroe EasyMx PRO v7a Manual

POWER
SUPPLY
Board contains switching power supply that creates stable voltage and current
levels necessary for powering each part of the board. Power supply section contains
specialized MC33269DT3.3 power regulator which creates VCC-3.3V power supply,
thus making the board capable of supporting 3.3V microcontrollers. Power supply
unit can be powered in three different ways: with USB power supply (CN20), using
external adapters via adapter connector (CN30) or additional screw terminals
(CN31). External adapter voltage levels must be in range of 9-32V DC and 7-23V AC.
Use jumper J9 to specify which power source you are using. Upon providing the power
using either external adapters or USB power source you can turn on power supply by
using SWITCH 1 (Figure 3-1). Power LED ON (Green) will indicate the presence of

power supply.

REG1
1
GND
2
Vout
3
VCC-5V Vin
C37
MC33269DT3.3
100nF
E17 C38
220uF/35V/LESR 100nF
3.3V VOLTAGE REGULATOR
E a s y M x P R O v 7 a U s e r M a n u a l
SWITCH1 VCC-5V
VCC-USB
VCC-3.3V
L1 220uH
VCC-SW
E16
J9C
10uF
E19 D7
220uF/35V/LESR MBRS140T3
U8
1 8 R69
SWC DRVC
0.22
2 7
SWE IPK
3 6 VCC-EXT
CT VIN
4 5
GND CMPR
C39 VCC-SW
220pF
MC34063A
E18
R74
220uF/35V/LESR
3K
R76
1K
5V SWITCHING POWER SUPPLY
VCC-5V
D6 D5
1N4007 1N4007
+ -
D4
D3
CN30
CN31
1N4007 1N4007
LD78A
POWER
R68
2K2