MC9S12E128 Datasheet, PDF (589/606 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Appendix A Electrical Characteristics
A.6 ATD Characteristics
This section describes the characteristics of the analog to digital converter.
The ATD is specified and tested for both the 3.3V and 5V range. For ranges between 3.3V and 5V the ATD
accuracy is generally the same as in the 3.3V range but is not tested in this range in production test.
A.6.1 ATD Operating Characteristics — 5V Range
The Table A-19 shows conditions under which the ATD operates.
The following constraints exist to obtain full-scale, full range results:
VSSA ≤ VRL ≤ VIN ≤ VRH ≤ VDDA. 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 A-19. 5V ATD Operating Characteristics
Conditions are shown in Table A-4 unless otherwise noted. Supply Voltage 5V-10% <= VDDA <=5V+10%
Num C
Rating
Symbol
Min
Typ
Max
Unit
1 D Reference Potential
2 C Differential Reference Voltage¹
Low
V_RL
V_SSA
—
V_DDA/2
V
High
V_RH
V_DDA/2
—
V_DDA
V
V_RH–V_RL
4.75
5.0
5.25
V
3 D ATD Clock Frequency
f_ATDCLK
0.5
—
2.0
MHz
4 D ATD 10-Bit Conversion Period
Clock Cycles² N_CONV10
14
—
28
Cycles
Conv, Time at 2.0MHz ATD Clock f_ATDCLK T_CONV10
7
—
14
µs
Conv, Time at 4.0MHz³ ATD Clock f_ATDCLK T_CONV10
3.5
—
7
µs
5 D ATD 8-Bit Conversion Period
Clock Cycles¹ N_CONV8
12
—
26
Cycles
Conv, Time at 2.0MHz ATD Clock f_ATDCLK T_CONV8
6
—
13
µs
6 D Stop Recovery Time (V_DDA = 5.0 Volts)
t_SR
—
—
20
µs
7 P Reference Supply current
I_REF
—
—
0.375
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.
3 _{Reduced accuracy see Table A-22 and Table A-23.}
MC9S12E128 Data Sheet, Rev. 1.07
Freescale Semiconductor
589