mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 1255

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

A.2.2.3
There are two cases to consider.
1
Freescale Semiconductor
Conditions are shown in
Num C
See also Table A-7. item 14
1
2
3
4
5
1. A current is injected into the channel being converted. The channel being stressed has conversion
2. Current is injected into pins in the neighborhood of the channel being converted. A portion of this
C Max input source resistance
C Disruptive analog input current
C Coupling ratio positive current injection
C Coupling ratio negative current injection
T Total input capacitance
values of $3FF ($FF in 8-bit mode) for analog inputs greater than V
than V
current is picked up by the channel (coupling ratio K), This additional current impacts the accuracy
of the conversion depending on the source resistance.
The additional input voltage error on the converted channel can be calculated as:
with I
Non sampling
Sampling
INJ
Current Injection
RL
V
being the sum of the currents injected into the two pins adjacent to the converted channel.
ERR
unless the current is higher than specified as disruptive condition.
Table A-4
= K * R
S
unless otherwise noted
Rating
* I
Table A-14. ATD Electrical Characteristics
INJ
1
MC9S12XDP512 Data Sheet, Rev. 2.17
Symbol
C
C
I
R
K
K
NA
INN
INS
S
p
n
–2.5
Min
—
—
—
—
—
Appendix A Electrical Characteristics
RH
and $000 for values less
Typ
—
—
—
—
—
—
Max
10
10
2.5
10
22
1
-4
-2
Unit
A/A
A/A
mA
K
pF
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