MPC555 / MPC556
ELECTRICAL CHARACTERISTICS
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
G-52
G.16 QADC64 Electrical Characteristics
Table G-16 QADC64 Conversion Characteristics (Operating)
(T
A
= T
L
to T
H
)
Num
Parameter
Symbol
Min
Max
Units
97
QADC Clock (QCLK) Frequency
1
NOTES:
1. Conversion characteristics vary with F
QCLK
rate. Reduced conversion accuracy occurs at max F
QCLK
rate.
F
QCLK
0.5
3.0
MHz
98
Conversion Cycles
2
2. The number of conversion cycles is dependent on the IST bits in the CCW register.
CC
14
28
QCLK cycles
99
Conversion Time
3
F
QCLK
= 2.0 MHz
1,4
Min = CCW/IST = 0b00
Max = CCW/IST = 0b11
3. Assumes that f
SYS
= 40 MHz
4. Assumes F
QCLK
= 2.00 MHz, with clock prescaler values of:
QACR0: PSH =0b01111, PSA = 0b0, PSL = 0b011)
CCW: BYP = 0b0
T
CONV
7.0
14.0
µ
s
100
Stop Mode Recovery Time
T
SR
—
10
µ
s
101
Resolution
5
5. At V
RH
– V
RL
= 5.12 V, one count = 5 mV (at 5.0 V, one count = 4.8875 mV).
—
5
—
mV
102
Absolute (Total Unadjusted) Error
6, 7, 8, 9
F
QCLK
= 2.0 MHz
3
, 2 Clock Input Sample Time
6. Accuracy tested and guaranteed at V
RH
– V
RL
= 5.0 V ± 0.5 V
7. This parameter is periodically sampled rather than 100% tested.
8. Absolute error includes 1/2 count (~2.5 mV) of inherent quantization error and circuit (differential, integral, and
offset) error. Characteristic assumes that adequate low-pass filtering is present on analog input pins — capacitive
filter with 0.01 µF to 0.1 µF capacitor between analog input and analog ground, typical source isolation imped-
ance of 10 Kbytes.
9. Input signals with large slew rates or high frequency noise components cannot be converted accurately. These
signals may affect the conversion accuracy of other channels.
AE
-2.0
2.0
Counts
103
DC Disruptive Input Injection Current
10, 11, 12, 13, 14
10. Below disruptive current conditions, the channel being stressed has conversion values of 0x3FF for analog in-
puts greater than V
RH
and 0x000 for values less than V
RL
. This assumes that V
RH
<= V
DDA
and V
RL
<= V
SSA
due to the presence of the sample amplifier. Other channels are not affected by non-disruptive conditions.
11. Exceeding limit may cause conversion error on stressed channels and on unstressed channels. Transitions
within the limit do not affect device reliability or cause permanent damage.
I
INJ
15
I
INJ
16
-3
-1
3
1
mA
104
Current Coupling Ratio
17
PQA
PQB
K
—
—
8x10
-5
8x10
-5
105
Incremental Error Due to Injection Current
All Channels Have Same 10 K
Ω
< Rs < 100 K
Ω
Channel Under Test has Rs = 10 K
Ω
, I
INJ
= +3 mA
E
INJ
+1.0
+1.0
Counts
106
Source Impedance At Input
18
R
S
—
100
K
Ω
107
Incremental Capacitance During Sampling
19
C
SAMP
—
5
pF
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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