MAC7100 Microcontroller Family Hardware Specifications, Rev. 1.2
Preliminary
Electrical Characteristics
Freescale Semiconductor
24
3.10 Analog-to-Digital Converter
Table 26 and
Table 27 show 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 because the
sample buffer amplifier cannot drive beyond the ATD power supply levels. If the input level goes outside of
this range it will effectively be clipped.
Table 26. ATD Operating Characteristics in 5.0 V Range
Conditions shown in
Table 7 unless otherwise noted
Num C
Rating
Symbol
Min
Typ
Max
Unit
N1
D Reference Potential
Low
High
VRL
VRH
VSSA
VDDA ÷ 2
—
VDDA ÷ 2
VDDA
V
N2
C Differential Reference Voltage 1
NOTES:
1. Full accuracy is not guaranteed when differential voltage is less than 4.50 V
VRH – VRL
4.50
5.00
5.50
V
N3
D ATD Clock Frequency
fATDCLK
0.5
—
2.0
MHz
N4
D ATD 10-bit Conversion PeriodfATDCLK Cycles
2
@ 2.0MHz fATDCLK
2. Minimum time assumes a sample period of 2 ATD clocks; maximum time assumes a sample period of 16 ATD clocks.
NCONV10
TCONV10
14
7
—
28
14
Cycles
μs
N5
D ATD 8-bit Conversion PeriodfATDCLK Cycles
@ 2.0MHz fATDCLK
NCONV8
TCONV8
12
6
—
26
13
Cycles
μs
N6
D Stop Recovery Time (VDDA = 5.0 V)
TREC
——
20
μs
N7
P Reference Supply current 1 ATD module on
IREF
—
0.200
0.255
mA
N8
P Reference Supply current 2 ATD modules on
IREF
—
0.400
0.510
mA
Table 27. ATD Operating Characteristics in 3.3 V Range
Conditions shown in Table 7, with VDDX = 3.3 V –5/+10% and a temperature maximum of +140°C unless otherwise noted.
Num C
Rating
Symbol
Min
Typ
Max
Unit
P1
D Reference Potential
Low
High
VRL
VRH
VSSA
VDDA ÷ 2
—
VDDA ÷ 2
VDDA
V
P2
C Differential Reference Voltage 1
NOTES:
1. Full accuracy is not guaranteed when differential voltage is less than 3.15 V
VRH – VRL
3.15
3.3
3.6
V
P3
D ATD Clock Frequency
fATDCLK
0.5
—
2.0
MHz
P4
D ATD 10-bit Conversion PeriodfATDCLK Cycles
2
@ 2.0MHz fATDCLK
2. Minimum time assumes a sample period of 2 ATD clocks; maximum time assumes a sample period of 16 ATD clocks.
NCONV10
TCONV10
14
7
—
28
14
Cycles
μs
P5
D ATD 8-bit Conversion PeriodfATDCLK Cycles
@ 2.0MHz fATDCLK
NCONV8
TCONV8
12
6
—
26
13
Cycles
μs
P6
D Stop Recovery Time (VDDA = 3.3 V)
TREC
——
20
μs
P7
P Reference Supply current 1 ATD module on
IREF
—
0.130
0.170
mA
P8
P Reference Supply current 2 ATD modules on
IREF
—
0.260
0.340
mA