ST7LITEU05 ST7LITEU09
11.3 10-BIT A/D CONVERTER (ADC)
11.3.1 Introduction
The on-chip Analog to Digital Converter (ADC) pe-
ripheral is a 10-bit, successive approximation con-
verter with internal sample and hold circuitry. This
peripheral has up to 5 multiplexed analog input
channels (refer to device pin out description) that
allow the peripheral to convert the analog voltage
levels from up to 5 different sources.
The result of the conversion is stored in a 10-bit
Data Register. The A/D converter is controlled
through a Control/Status Register.
11.3.2 Main Features
■ 10-bit conversion
■ Up to 5 channels with multiplexed input
Figure 40. ADC Block Diagram
■ Linear successive approximation
■ Data register (DR) which contains the results
■ Conversion complete status flag
■ On/off bit (to reduce consumption)
The block diagram is shown in Figure 40.
11.3.3 Functional Description
11.3.3.1 Analog Power Supply
VDD and VSS are the high and low level reference
voltage pins.
Conversion accuracy may therefore be impacted
by voltage drops and noise in the event of heavily
loaded or badly decoupled power supply lines.
fCPU
DIV 2
0
1
DIV 4
1
0
SLOW
bit
fADC
EOC SPEED ADON 0
0 CH2 CH1 CH0 ADCCSR
3
AIN0
AIN1
AINx
ANALOG
MUX
RADC
HOLD CONTROL
CADC
ANALOG TO DIGITAL
CONVERTER
ADCDRH
D9 D8 D7 D6 D5 D4 D3 D2
ADCDRL
00
0
0 SLOW 0 D1 D0
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