MC9S12T64 Datasheet, PDF (569/608 Pages) Motorola, Inc – Specification

Freescale Semiconductor, Inc.
Electrical Characteristics
ATD Characteristics
ATD Characteristics
This section describes the characteristics of the analog to digital
converter.
ATD Operating
Characteristics
The Table 110 shows conditions under which the ATD operates.
The following constraints exist to obtain full-scale, full range results:
V_SSA ≤ V_RL ≤ V_IN ≤ V_RH ≤ V_DDA. This constraint exists since the sample
buffer amplifier can not drive beyond the power supply levels that it ties
to. If the input level goes outside of this range it will effectively be clipped.
Table 110 ATD Operating Characteristics
Conditions are shown in Table 106 unless otherwise noted
Num
Rating
Symbol
Min
Typ
Max Unit
Reference Potential
1
2 Differential Reference Voltage⁽¹⁾
Low V_RL
High V_RH
V_SSA
V_DDA/2
V_DDA/2
V
V_DDA
V
V_RH–V_RL
4.75
5.0
5.25
V
3 ATD Clock Frequency
f_ATDCLK
0.5
2.0
MHz
ATD 10-Bit Conversion Period
4
Clock Cycles⁽²⁾ N_CONV10
14
Conv, Time at 2.0MHz ATD Clock f_ATDCLK T_CONV10
7
28 Cycles
14
µs
ATD 8-Bit Conversion Period
5
Clock Cycles⁽²⁾ N_CONV8
12
Conv, Time at 2.0MHz ATD Clock f_ATDCLK T_CONV8
6
26 Cycles
13
µs
5 Stop Recovery Time (V_DDA=5.0 Volts)
t_SR
20
µs
6 Reference Supply current
I_REF
0.75
mA
1. Full accuracy is not guaranteed when differential voltage is less than 4.75V
2. The minimum time assumes a final sample period of 2 ATD clocks cycles while the maximum time assumes a final sample
period of 16 ATD clocks.
Factors
Influencing
Accuracy
Two factors - source resistance and source capacitance - have an
influence on the accuracy of the ATD.
Electrical Characteristics
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MC9S12T64Revision 1.1.1