MC68HCP11 Datasheet, PDF (41/45 Pages) Motorola, Inc – 8-Bit Microcontroller

10 Analog-to-Digital Converter
The A/D converter system uses an all capacitive charge redistribution technique to convert analog sig-
nals to digital values. The MC68HC11A8 A/D system is an 8-channel, 8-bit, multiplexed-input, succes-
sive-approximation converter and is accurate to ±1 least significant bit (LSB). It does not require
external sample and hold circuits because of the type of charge redistribution technique used.
Dedicated lines V_RH and V_RL provide the reference supply voltage inputs. Refer to the A/D converter
block diagram.
A multiplexer allows the single A/D converter to select one of 16 analog signals, as shown in the ADCTL
register description.
PE0
AN0
PE1
AN1
PE2
AN2
PE3
AN3
ANALOG
MUX
PE4
AN4
PE5
AN5
PE6
AN6
PE7
AN7
8-BIT CAPACITIVE DAC
WITH SAMPLE AND HOLD
SUCCESSIVE APPROXIMATION
REGISTER AND CONTROL
RESULT
ADCTL A/D CONTROL
V_RH
V_RL
INTERNAL
DATA BUS
RESULT REGISTER INTERFACE
ADR1 A/D RESULT 1
ADR2 A/D RESULT 2
ADR3 A/D RESULT 3
ADR4 A/D RESULT 4
Figure 13 A/D Converter Block Diagram
EA9 A/D BLOCK
MC68HC11A8
MC68HC11A8TS/D
MOTOROLA
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