
ANALOG-TO-DIGITAL CONVERTER
MC68HC11F1
10-2
TECHNICAL DATA
Figure 10-1 A/D Converter Block Diagram
Port E pins can also be used as digital inputs. Reads of port E pins are not recom-
mended during the sample portion of an A/D conversion cycle, when the gate signal
to the N-channel input gate is on. Because no P-channel devices are directly connect-
ed to either input pins or reference voltage pins, voltages above VDD do not cause a
latchup problem, although current should be limited according to maximum ratings.
Refer to Figure 10-2, which is a functional diagram of an input pin.
PE0/
AN0
PE1/
AN1
PE2/
AN2
PE3/
AN3
PE4/
AN4
PE5/
AN5
PE6/
AN6
PE7/
AN7
ANALOG
MUX
8-BIT CAPACITIVE DAC
WITH SAMPLE AND HOLD
SUCCESSIVE APPROXIMATION
REGISTER AND CONTROL
ADCTL A/D CONTROL
CB
CC
CD
MULT
SCAN
CCF
CA
ADDR 3 A/D RESULT 3
RESULT REGISTER INTERFACE
RESULT
INTERNAL
DATA BUS
VRH
VRL
ADDR 4 A/D RESULT 4
ADDR 2 A/D RESULT 2
ADDR 1 A/D RESULT 1
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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