MC9S12G FREESCALE [Freescale Semiconductor, Inc], MC9S12G Datasheet - Page 1091

• Manufacturer Part Number: MC9S12G
• Description: Ignores external trigger. Performs one conversion sequence and stops.
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

A.3.2.3
When sampling an additional internal capacitor is switched to the input. This can cause a voltage drop due
to charge sharing with the external and the pin capacitance. For a maximum sampling error of the input
voltage ≤ 1LSB (10-bit resilution), then the external filter capacitor, C
A.3.2.4
There are two cases to consider.
1
A.3.3
Table A-16
current injection, input capacitance and source resistance.
Freescale Semiconductor
Supply voltage 3.13 V < V
Num C
1 Refer to
1
2
3
4
5
6
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
This document is valid for the S12G96 and the S12G128 device. All information related to other devices is preliminary.
C Max input source resistance
D Total input capacitance Non sampling
D Input internal Resistance
C Disruptive analog input current
C Coupling ratio positive current injection
C Coupling ratio negative current injection
values of $3FF (in 10-bit mode) for analog inputs greater than V
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
RL
Total input capacitance Sampling
A.3.2.2
ATD Accuracy
and
unless the current is higher than specified as disruptive condition.
INJ
Source Capacitance
Current Injection
V
Table A-18
being the sum of the currents injected into the two pins adjacent to the converted channel.
ERR
for further information concerning source resistance
= K * R
DDA
< 5.5 V, -40
specifies the ATD conversion performance excluding any errors due to
S
Rating
* I
Table A-15. ATD Electrical Characteristics
MC9S12G Family Reference Manual, Rev.1.01
1
INJ
o
C < T
J
< 150
o
C
Symbol
C
C
R
I
R
K
K
NA
INN
INS
INA
S
p
n
f
Min
-2.5
≥ 1024 * (C
—
—
—
—
—
RH
-
and $000 for values less than
Typ
—
—
—
—
—
—
5
INS
Electrical Characteristics
–C
INN
1E-4
5E-3
Max
2.5
10
16
15
1
).
Unit
A/A
A/A
mA
KΩ
kΩ
pF
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