UPD78F0411GA-GAM-AX Datasheet, PDF (306/564 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 12 10-BIT SUCCESSIVE APPROXIMATION TYPE A/D CONVERTER (μPD78F041x only)
12.4.2 Input voltage and conversion results
The relationship between the analog input voltage input to the analog input pins (ANI0 to ANI5) and the theoretical
A/D conversion result (stored in the 10-bit A/D conversion result register (ADCR)) is shown by the following
expression.
VAIN
SAR = INT (
× 1024 + 0.5)
AVREF
ADCR = SAR × 64
or
ADCR
(
− 0.5) ×
AVREF
ADCR
≤ VAIN < (
+ 0.5) × ^AVREF
64
1024
64
1024
where, INT( ): Function which returns integer part of value in parentheses
VAIN: Analog input voltage
AVREF: AVREF pin voltage
ADCR: A/D conversion result register (ADCR) value
SAR: Successive approximation register
Figure 12-12 shows the relationship between the analog input voltage and the A/D conversion result.
Figure 12-12. Relationship Between Analog Input Voltage and A/D Conversion Result
SAR
ADCR
1023
FFC0H
1022
FF80H
A/D conversion result
1021
3
FF40H
00C0H
2
0080H
1
0040H
0
113253
2048 1024 2048 1024 2048 1024
0000H
2043 1022 2045 1023 2047 1
2048 1024 2048 1024 2048
Input voltage/AVREF
304
User’s Manual U18698EJ1V0UD