Cirrus Logic CDB5484U - Manual (Page 11)

CDB5484U
DS919DB5 11
1.5 Power Supply Section
Table 4 illustrates the power supply connections on the evaluation board. The positive analog (VDDA) for
the CS5484 can be supplied using the +3.3V binding post (J36 and J37) or the onboard +3.3V regulator.
Jumper J38 allows the VDDA supply to be sourced from the +3.3V binding post (J37) or the regulated
+3.3V supply. The DC-DC converter (U8) powers the onboard +3.3V regulator. Jumper J26 allows the
+5V supply to be sourced from either the +5V EXT screw connector (J27) or the +5V USB supply. The
+5V supplies the power for the microcontroller (8051_REGIN) and the DC-DC converter (U8). Jumper J21
is used to measure the CS5484 analog supply current and must be installed.
When connecting the CDB5484U board to the AC line through non-isolated sensors, it is strongly recom-
mended that the CS5484 GND reference is connected to the neutral, the non-isolated current sensor is
connected to the neutral, and the CS5484 is supplied by +3.3V isolated from AC line. The DC-DC con-
verter (U8) provides 1kVDC isolation, while no isolation is provided for the 3.3V binding post connections.
If +3.3V is used from the binding post, then the external 3.3VDC power supply must be isolated from the
AC line. To prevent electric shock and damages, always use an isolated power source.
Table 4. Power Supply Selection
Supp
Sour
USB
External
&
USB
Externa
ply
rce
CS
So
B
On
3
Re
l +3.3V
B
B
al +5V
On
3
reg
S5484
ource
Bi
p
J3
n-board
3. 3 V
egulator
inding
Post
+
n-board
3.3V
gulator
nding
post
6&J37
U
Su
J
NC +
+3.3 V +
NC N
USB
upply
J24
5
Term
J
+5V N
+5V N
NC +
5V
minals
J27
J
NC
Ƒ V
ż V
(de
NC
Ƒ V
ż V
+5V
Ƒ V
ż V
VDDA
J21
VDDA
VDDA
efault)
Ƒ +
ż V
ż +
(d
VDDA
VDDA Ƒ +
ż V
ż +
VDDA
VDDA Ƒ +
ż V
ż +
J38
+
+3.3V
VDDA
+3.3V_2
efault)
Ƒ
ż
ż
(
+3.3V
VDDA
+3.3V_2
Ƒ
ż
ż
+3.3V
VDDA
+3.3V_2 Ƒ
ż
ż
+3.3V_1
J26
+5V EXT
+5V
+5V USB
(default)
+5V EXT
+5V
+5V USB
+5V EXT
+5V
+5V USB