NAU8224
NAU8224 User Manual
April, 2016
Rev 1.0
When using a power supply, it is recommended to use a 330
µF capacitor across the power pins to
suppress any supply glitches, as a safety measure. When a battery is used, the capacitor is
not required. In normal applications too, the capacitor is not required.
2 wire interface header
The EVB has a 10 pin header which includes a 2 wire interface to control the volume for finer gain
settings. The section of the schematic is shown above. In order to be able to control volume using this
interface, J20 jumper must be installed. This connects the header to the NAU8224 volume control pins.
Pin 3 is a GPIO pin which connects to the enable (EN) pin of the chip. Pins 5 and 7 are the serial Data
and Serial clock lines. An external 2-wire master can be used to send the commands. The bundled
USB dongle could be used to control the volume using the NAU8224 GUI. Pin 10 is the ground pin.
J20
HEADER 2
1
2
VDDA
J24
HEADER5X2X100
1
2
3
4
5
6
7
8
9
10
R21
2.2
R14
47k
TP17
USB Connector
Male
R17
100
USBVDD Jumper
SCLK
TP16
R18
100
VDDA
SDIO
GPIO
C29
1nF
R15
47k
