Rev. 1.00
72
August 29, 2018
Rev. 1.00
73
August 29, 2018
HT45F6530
AC Voltage Regulator Flash MCU
HT45F6530
AC Voltage Regulator Flash MCU
Analog to Digital Converter
The need to interface to real world analog signals is a common requirement for many electronic
systems. However, to properly process these signals by a microcontroller, they must first be
converted into digital signals by A/D converters. By integrating the A/D conversion electronic
circuitry into the microcontroller, the need for external components is reduced significantly with the
corresponding follow-on benefits of lower costs and reduced component space requirements.
A/D Converter Overview
This device contains a multi-channel analog to digital converter which can directly interface to
external analog signals, such as that from sensors or other control signals and convert these signals
directly into a 12-bit digital value. It also can convert the internal signals, such as the PGA output
divided voltage, the A/D power divided voltage and the OPA output voltage, into a 12-bit digital
value. The external or internal analog signal to be converted is determined by the SAINS3~SAINS0
bits together with the SACS3~SACS0 bits. When the external analog signal is to be converted,
the corresponding pin-shared control bits should first be properly configured and then desired
external channel input should be selected using the SAINS3~SAINS0 and SACS3~SACS0 bits.
Note that when the internal analog signal is to be converted, the external channel input signal will
automatically be disconnected regardless of the SACS bit field value. More detailed information about
the A/D input signal is described in the “A/D Converter Control Registers” and “A/D Converter
Input Signals” sections respectively.
External Input Channels
Internal Signals
A/D Channel Select Bits
6: AN0~AN5
8: V
DD
, V
DD
/2, V
DD
/4,
V
R
, V
R
/2, V
R
/4,
V
OPA0O
, V
OPA1O
SAINS3~SAINS0,
SACS3~SACS0
The accompanying block diagram shows the overall internal structure of the A/D converter, together
with its associated registers.
Pin-shared
Selection
SACS3~SACS0
SAINS3~SAINS0
A/D Converter
START
ADBZ ADCEN
V
SS
A/D Clock
÷ 2
N
(N=0~7)
f
SYS
SACKS2~
SACKS0
V
DD
ADCEN
SADOL
SADOH
AN0
AN1
AN5
A/D Reference Voltage
A/D Data
Registers
V
DD
V
DD
/2
V
DD
/4
V
R
V
R
/2
V
R
/4
ADRFS
V
DD
VREF
Pin-shared
Selection
PGA
V
RI
V
BG
PGAGS1~PGAGS0
(Gain=1/2/3/4)
ADPGAEN
V
R
VREFI
PGAIS
Pin-shared
Selection
V
OPA0O
V
OPA1O
SAVRS1~SAVRS0
A/D Converter Structure