Hardware
UM0193
1.9 Power
supplies
The L5973AD DC/DC converter (U6) supplies the ARMIC30 Evaluation Board with a +5V
DC voltage supply using feedback resistors (R37 and R38) as shown in
. A green
LED (D13) lights up when this supply is present.
An addi3.3V DC linear voltage regulator (U7) connected in cascade to the DC/DC
converter output can be used to supply the JTAG connector and level converting resistors
with a +3.3V DC supply voltage. Use jumper J33 to select either a DC/DC reference voltage
or a linear regulator as described in
Section 1.6.1: JTAG supply voltages
and
.
Connectors J30 or J31 provide the ARMIC30 Evaluation Board power supplies. Connector
J30 includes a polarity protection diode and is suitable for use with a standard mains
adapter having an output voltage range b7 and +30V DC. Connector J31 is
connected directly to the DC/DC converter input which is over-voltage protected by a transil
diode (D8) for a recommended supply voltage range b6 and +30V DC. The
ARMIC30 Evaluation Board clearly indicates the power supply polarity.
Figure 15.
Power supply schematic diagram
5V_TP
5V
3V3
5V
5V
5V
5V
1
2
J34
J34
STPS340U
D7
STPS340U
D7
+
CO
M
P
4
IN
H
3
Vin
8
SYNC
2
FB
5
OUT
1
VREF
6
GN
D
7
GN
D
9
U6
U6
1
2
J32
J32
+
R38
3k9
R38
3k9
C38
100n
C38
100n
+
+
R39
6k2
R39
6k2
C36
22nF
C36
22nF
C37
100n
C37
100n
+
1
2
3
J33
J33
R37
12k
R37
12k
L1
L1
1
2
1
2
3
C35
100pF
C35
100pF
+
GN
D
4
VOUT
3
VIN
1
Ai12503
C43
10M/16V
C42
10M/16V
C41
10M/16V
C40
10M/16V
LF33/DPAK
U7
C34
100 µF
16V
5V_TP
33 µH
C33
10 µF
35V
D8
SM6T33A
D6
STPS340U
J30
PS CON
J31
24V Terminal Block
L5973AD
C39
2M2/16V
