Power Supply Selection - Cirrus Logic CDB5480U General Description Manual

1.5

Power Supply Selection

Table 4 illustrates the power supply connections on the evaluation board. The positive analog (VDDA) for
the CS5480 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 CS5480 analog supply current and must be installed.
When connecting the CDB5480U board to the AC line through non-isolated sensors, it is strongly
recommended that the CS5480 GND reference is connected to the neutral, the non-isolated current
sensor is connected to the neutral, and the CS5480 is supplied by +3.3V isolated from the AC line. The
DC-DC converter (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.
On n-board
3. 3
Re egulator
B
On n-board
reg gulator
10
Table 4. Power Supply Selection
J3 6&J37
3 V NC
inding
+3.3 V +
Post
3.3V 3
NC
J24 J J27 J
+5V + N NC
+5V + N NC
NC N + +5V
CDB5480U
J21 J J38
+ +3.3V
V VDDA
V VDDA
VDDA V
+ +3.3V_2
(de efault)
(d efault)
+ +3.3V
VDDA V
VDDA V
V VDDA
+3.3V_2 +
+3.3V +
VDDA V
VDDA V
V VDDA
+3.3V_2 +
J26
+5V EXT
+5V
+5V USB
(default) (
+5V EXT
+5V
+5V USB
+5V EXT
+5V
+5V USB
DS893DB5