MOTOROLA
12-4
MC68HC05X16
Rev. 1
ELECTRICAL SPECIFICATIONS
12
12.3
A/D converter characteristics
(1)Performance verified down to 2.5V
VR, but accuracy is tested and guaranteed at
VR = 5V
±
10%.
(2) Source impedances greater than 10k
will adversely affect internal charging time during input sampling.
(3) The external systemerror caused by input leakage current is approximately equal to the product of R source and input
current. Input current to A/D channel will be dependent on external source impedance (see
Figure 9-2
).
Table 12-3
A/D characteristics
(V
DD
= 5.0 Vdc
±
10%, V
SS
= 0 Vdc, T
A
= –40
°
C to +125
°
C)
Characteristic
Resolution
Number of bits resolved by the A/D
Non-linearity
Max deviation fromthe best straight line through the A/D
transfer characteristics
(V
RH
= V
DD
and V
RL
= 0V)
Quantization error
Uncertainty due to converter resolution
Absolute accuracy
Difference between the actual input voltage and the
full-scale equivalent of the binary code output code for all
errors
Conversion range
Analog input voltage range
V
RH
Maximumanalog reference voltage
V
RL
Mnimumanalog reference voltage
V
R(1)
Mnimumdifference between V
RH
and V
RL
Conversion time
Total time to performa single analog to digital conversion
a. External clock (OSC1, OSC2)
b. Internal RC oscillator
Monotonicity
Conversion result never decreases with an increase in
input voltage and has no mssing codes
Zero input reading
Conversion result when V
IN
= V
RL
Full scale reading
Conversion result when V
IN
= V
RH
Sample acquisition time Analog input acquisition sampling
a. External clock (OSC1, OSC2)
b. Internal RC oscillator
(2)
Sample/hold capacitance Input capacitance on PD0/AN0–PD7/AN7
Input leakage
(3)
Input leakage on A/D pins PD0/AN0–PD7/AN7, VRL, VRH
Parameter
Mn
8
Max
—
Unit
Bit
—
±
0.5
LSB
—
±
0.5
LSB
—
±
1
LSB
V
RL
V
RL
V
RH
V
V
V
V
V
DD
+ 0.1
V
RH
—
V
SS
– 0.1
3
—
—
32
32
t
CYC
s
GUARANTEED
00
—
—
FF
Hex
Hex
—
—
—
—
12
12
12
1
t
CYC
s
pF
μ
A