Easy
PIC
for dsPIC30
®
v7
page 6
Dual 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 two power
regulators: MC34063A, which generates VCC-
5V, and MC33269DT3.3 which creates VCC-3.3V
power supply. Board can be powered in three different
ways: with USB power supply (CN1), using external adapters
via adapter connector (CN25) or additional screw terminals
(CN24). External adapter voltage levels must be in range of 9-32V DC
and 7-23V AC. Use jumper J8 to specify which power source you are using,
and jumper J16 to specify whether you are using 5V or 3.3V power supply. Upon
providing the power using either external adapter, or USB power source, you can turn
on power supply by using SWITCH 1 (Figure 3-1). Power LED (Green ON) will indicate the
presence of power supply.
Figure 3-2: Dual power supply unit schematics
Figure 3-1: Power supply unit of EasyPIC
™
v7 for dsPIC30
®
VCC-5V
R42
2K2
LD48
2
C44
100nF
VCC-5V
1
3
GND
Vout
Vin
REG1
MC33269DT3.3
E6
10uF
VCC-3.3V
E8
220uF/35V
C43
100nF
3.3V VOLTAGE REGULATOR
8
7
6
5
1
2
3
4
SWC
SWE
CT
GND
DRVC
IPK
VIN
CMPR
U6
MC34063A
R36
0.22
R43
3K
VCC-SW
C45
220pF
D5
MBRS140T3
L1
220uH
E9
220uF/35V
VCC-EXT
R44
1K
VCC-5V
J8
2
1
3
SWITCH1
VCC-USB
VCC-SW
D2
1N4007
D1
1N4007
D4
1N4007
D3
1N4007
CN25
CN24
E7
220uF/35V
5V SWITCHING POWER SUPPLY
VCC-USB
FP1
C3
100nF
1
2
3
4
VCC
GND
D-
D+
CN1
USB
J16
VCC-5V
VCC-BRD
VCC-3.3V
POWER
po
w
er supply
