Freescale Semiconductor, Inc.
Analog Subsystem
Analog Multiplex Register
V
DD
PB0
+
COMP2
-
INTERNAL
TEMPERATURE
DIODE
CHANNEL
SELECTION
BUS
8 K0
SAMPLE
CAP
8 K0
VOFF
OPT (MOR)
HOLD
V
SS
OFFSET
DHOLD
Figure 8-3. Comparator 2 Input Circuit
Table 8-1 Comparator 2 Input Sources
HOLD DHOLD
(AMUX) (AMUX) (MOR)
OPT
VOFF
(ASR)
Voltage
Offset
Source To Negative Input
Case
of Comparator 2
0
1
X
0
Sample capacitor connected to comparator
2 negative input; very low leakage current.
No
Hold
Sample
Voltage
0
0
Sample capacitor connected to comparator
2 negative input; bottom of capacitor
1
1
Yes
offset from V by approximately 100 mV,
SS
very low leakage current.
Signal on channel selection bus is divided
by 2 and connected to sample capacitor
and comparator 2 negative input
Divided
Input
0
1
1
1
0
1
X
X
X
X
X
X
No
No
No
Signal on channel selection bus is
connected directly to sample capacitor
and comparator 2 negative input.
Direct
Input
Internal
Temperature
Diode
Internal temperature sensing diode
connected directly to sample capacitor
and comparator 2 negative input.
X = Don’t Care
MC68HC705JJ7/MC68HC705JP7 — Rev. 3.0
General Release Specification
Analog Subsystem
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