CODEC Motherboard Manual Version 1.3
Page 41 of 66
April 12, 2016
CODEC Motherboard
19.1
Summary of Power Options and Limits
IMPORTANT: Physical orientation of the various power selection jumpers is NOT the same.
Each jumper must be examined carefully to determine its Pin #1 designator and orientation. The
connector Pin #1 is marked with a white square in the silkscreen pattern on the PCB.
Connector
Name
Signal
Name
Supply Range
and Limits
Option
Jumper
Name
Power optioning description
Important: Note carefully the differing
pin #1 positions on each jumper
CON1
USB
USB host limited
n/a
Power is normally supplied entirely from the USB host.
Series diodes will substitute power from the greater of
either P1 or from J26 if either source is greater than
5Vdc from the USB host.
P1
5vDC Center Pin =
Positive (+V)
0.0Vdc to 5.5Vdc
n/a
Note: There is no jumper for this option. Series diodes
pass power from P1 if this voltage is greater than 5Vdc
coming from USB
J6
DGND
0V (digital ground)
n/a
n/a
J18
EXT_VDDC
1.6Vdc to 3.6Vdc
J17
Pin 1-2 shorted selects External VDDC via J18
Pin 3-4 shorted selects VDDC=VDDB
Pin 5-6 shorted selects VDDC=1.8Vdc
J19
EX_VDDA
2.5V to 3.6V
VDDA
must be ≥
VDDC
J21
Pin 1-2 shorted selects external VDDA via J19
Pin 2-3 shorted selects VDDA = 3.3Vdc
J22
EXT_VDDB
1.8V to 3.6V
VDDB
must be ≥
VDDC
J20
Pin 1-2 shorted selects External VDDB via J22
Pin 2-3 shorted selects VDDB=3.3Vdc
J26
EXT_+5V_IN
0.0Vdc to 5.5Vdc
n/a
Note: There is no jumper for this option. Series diodes
pass power from J26 if this voltage is greater than 5Vdc
coming from USB
J36
EX_VDDSPK
2.5V to 5.0V
J25
Pin 1-2 shorted selects external VDDSPK via J36
Pin 3-4 shorted selects built-in 5.0Vdc
Pin 5-6 shorted selects VDDSPK = VDDA
Default factory configuration highlighted in color
Table 1: POWER OPTIONS
19.2
Main 5Vdc Power
All power is usually supplied to the NAU8822-EVB USB interface via the USB connector. It
should be noted that the voltage supplied via USB is nominally 5Vdc. However, this voltage
supplied by the external USB host may be significantly less, especially if driving a loudspeaker at
high volume using the device on the daughter card.
With most USB host devices and USB cables, it is not possible to achieve the full rated 1-Watt of
loudspeaker power using only USB as the power source. Additionally, long or poor quality USB
cables can cause the EVB to operate unreliably. The USB cable used with the EVB should be a
high quality product and not longer than 1-meter.
If the primary purpose to use alternative power is to drive the speaker output to the full rated
power, it is preferred to simply substitute an external supply for VDDSPK via J36. EVB operation
is simpler if the main 5Vdc power other than for VDDSPK is supplied from the USB host.
