mc68hc11e0fnr2 Freescale Semiconductor, Inc, mc68hc11e0fnr2 Datasheet - Page 58

• Manufacturer Part Number: mc68hc11e0fnr2
• Description: Hc11 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Analog-to-Digital (A/D) Converter
58
AN0
AN1
AN2
AN3
AN4
AN5
AN6
AN7
PE0
PE1
PE2
PE3
PE4
PE5
PE6
PE7
ANALOG
INPUT
PIN
* THIS ANALOG SWITCH IS CLOSED ONLY DURING THE 12-CYCLE SAMPLE TIME.
Figure 3-2. Electrical Model of an A/D Input Pin (Sample Mode)
ADR1 A/D RESULT 1
ANALOG
PROTECTION
MUX
< 2 pF
DEVICE
INPUT
Figure 3-1. A/D Converter Block Diagram
+ ~20 V
– ~0.7 V
M68HC11E Family Data Sheet, Rev. 5.1
RESULT
ADR2 A/D RESULT 2
SUCCESSIVE APPROXIMATION
+ ~12V
– ~0.7V
DUMMY N-CHANNEL
OUTPUT DEVICE
REGISTER AND CONTROL
WITH SAMPLE AND HOLD
RESULT REGISTER INTERFACE
8-BIT CAPACITIVE DAC
ADR3 A/D RESULT 3
DIFFUSION/POLY
ADCTL A/D CONTROL
JUNCTION
LEAKAGE
400 nA
COUPLER
ð 4 kΩ
ADR4 A/D RESULT 4
~ 20 pF
*
Freescale Semiconductor
CAPACITANCE
V
RL
DAC
V
V
INTERNAL
DATA BUS
RH
Rl