Data Sheet

NAU7802 24-bit ADC
Nuvoton Confidential - 34 - Revision 1.7
11.9 REG0x12-REG0x14: ADC Conversion Result
REG0x12 (Read Only)
ADCO_B2
ADC Conversion Result bit 23 to bit 16
REG0x13 (Read Only)
ADCO_B1
ADC Conversion Result bit 15 to bit 8
REG0x14 (Read Only)
ADCO_B0
ADC Conversion Result bit 7 to bit 0
Before reading an ADC Conversion Result, check if REG0x00 bit 5 CR=1 or DRDY pin
showing Data Ready first. If not showing Data Ready, but a read of REG0x12 is performed, it
will latch and shift out the previous conversion result.
There are two options are necessary read a complete 24 bit ADC conversion result:
Option 1: Use "I2C Burst Read 3 bytes"
Issue I2C burst read 3 bytes sequence with starting address 0x12. In read data section of this
burst read sequence, continuously read 3 bytes of data, the first byte will be the bit 23 to bit 16,
the second byte will be bit 15 to bit 8, the third byte will be bit 7 to bit 0 of the ADC
conversion result.
Option 2: Use 3 "I2C Single Read"
Step 1: Read REG0x12: bit 23 to bit 16 ADC conversion result will be shift out
Step 2: Read REG0x13: bit 15 to bit 8 ADC conversion result will be shift out
Step 3. Read REG0x14: bit 7 to bit 0 ADC conversion result will be shift out
Note: The full 24-bit ADC conversion result is latched when the read REG0x12 command is
decoded by the NAU7802. The following read of R0x13 and R0x14 will shift out the
remainder of the latched ADC conversion result. This guarantees the 3 bytes of the data are
from the same ADC sample conversion.