Rev. 1.00
124
September 11, 2018
Rev. 1.00
125
September 11, 2018
HT45F4050
A/D NFC Flash MCU
HT45F4050
A/D NFC Flash MCU
A/D Conversion Rate and Timing Diagram
A complete A/D conversion contains two parts, data sampling and data conversion. The data
sampling which is defined as t
ADS
takes 4 A/D conversion clock cycles and the data conversion takes
12 A/D converter clock cycles. Therefore a total of 16 A/D conversion clock cycles for an A/D
conversion which is defined as t
ADC
are necessary.
Maximum single A/D conversion rate=A/D conversion clock period /16
The accompanying diagram shows graphically the various stages involved in an analog to digital
conversion process and its associated timing. After an A/D conversion process has been initiated
by the application program, the microcontroller internal hardware will begin to carry out the
conversion, during which time the program can continue with other functions. The time taken for the
A/D conversion is 16t
ADCK
clock cycles where t
ADCK
is equal to the A/D conversion clock period.
ADCEN
START
ADBZ
SACS[3:0]
off
on
off
on
t
ON2ST
t
ADS
A/D sampling time
t
ADS
A/D sampling time
Start of A/D conversion
Start of A/D conversion
Start of A/D conversion
End of A/D
conversion
End of A/D
conversion
t
ADC
A/D conversion time
t
ADC
A/D conversion time
t
ADC
A/D conversion time
0011B
0010B
0000B
0001B
A/D channel switch
(SAINS[3:0]=0000B)
A/D Conversion Timing – External Channel Input