page 6
Power supply
Figure 3-2: Power supply unit schematic
VCC-5V
POWER
R28
2K2
LD1
ON/OFF
8
7
6
5
1
2
3
4
U5
SWC
SWE
CT
GND
DRVC
IPK
VIN
CMPR
MC34063A
R29
0.22
R30
3K
VCC-SW
C22
220pF
D5
MBRS140T3
L1
220uH
E8
220uF/35V
/LESR
VCC-EXT
R31
1K
VCC-5V
J1
2
1
3
SWITCH1
VCC-USB
VCC-SW
+
-
D2
1N4007
D1
1N4007
D4
1N4007
D3
1N4007
CN36
CN35
E7
220uF/35V/LESR
5V SWITCHING POWER SUPPLY
1
3
REG1
C21
100nF
VCC-5V
2
GND
Vout
Vin
MC33269DT3.3
E5
10uF
3.3V VOLTAGE REGULATOR
VCC-3.3V
E6
220uF/35V/LESR
C20
100nF
VCC-USB
FP1
C5
100nF
1
4
VCC
GND
CN5
USB
Figure 3-1: Power supply unit of mikromedia
™
workStation v7
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
(CN5)
, using external adapters via adapter connector
(CN36)
or additional screw terminals
(CN35)
. External adapter voltage levels
must be in range of
9-32V DC and 7-23V AC
. Use jumper
J1
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.
po
w
er supply
