HT66F0042 Datasheet, PDF (101/178 Pages) Holtek Semiconductor Inc – A/D Flash MCU with EEPROM

HT66F0042/HT66F0082
A/D Flash MCU with EEPROM
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 Overview
The devices contain an 8-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. The external or internal analog signal to be converted is determined by the
SAINS and SACS bit fields. Additionally note that when the internal analog signal is to be converted,
the pin-shared control bits should also be properly configured first. More detailed information
about the A/D input signal is described in the “A/D Converter Control Registers” and “A/D
Converter Input Signal” sections respectively.
Input Channels
8
A/D Channel Select Bits
SAINS2~SAINS0, SACS2~SACS0
Input Pins
AN0~AN7
The accompanying block diagram shows the overall internal structure of the A/D converter, together
with its associated registers.
Pin-sha�ed sele�tion
AN0
AN�
AN�
AN7
AVDD
VR
SACS[�:0]
ENADC
MUX
SAPIN
1�-�it
SAR ADC
VREFO
ADBZ
SADOH[7:0]
SADOL[7:0]
SAINT
VREFO
VREF
VBG
(1.04V)
SAINS[�:0]
PBS0
VRI
AVDD
V_R
ENOPA
OPA
Divide�
fSYS
SACKS[�:0]
SAVRS[3:0]
A/D Converter Structure
Rev. 1.30
101
December 05, 2016