Data Sheet

NAU7802 24-bit ADC
Nuvoton Confidential - 27 - Revision 1.7
9.4 16-pin application circuit
The built-in voltage regulator and built-in oscillator enable very low parts count applications as shown
here. The signal input filter is optional, depending on the application requirements and can be
expanded with decoupling capacitors to ground if needed. With a lithium-ion battery, an external
voltage regulator for the DVDD supply may also be optional.
47
24-bit ADC
47
0.1uF
Load
Cell
MCU
VDD
I/O
I/O
I/O
REFN
VBG
AVSS
2
1
4
3
6
5
8
7
VIN2N
VIN1P
VIN2P
VIN1N
REFP
14
15
12
13
10
11
9
16
DVSS
XIN
XOUT
DVDD
SDIO
SCLK
DRDY
AVDD
16-pin
0.1uF
0.1uF
VSS
Battery
Charge
Circuit
Battery
1uF
1uF
Cfilter
For single channel applications, Cfilter can be added for enhanced ENOB at high PGA gain settings.
The filter capacitor Cfilter provides additional filtering at the PGA output. It can be enabled by setting
PGA_CAP_EN, Register 0x1C[7]=1. The following values are recommended for Cfilter:
AVDD Supply Voltage (Volt)
3.3
4.5
Cfilter (pF)
330
680