MOTOROLA
F-22
MC68HC05B6
Rev. 4
MC68HC705B16N
14
F.8
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 8-2).
Table F-9
A/D characteristics for 5V operation
(V
DD
= 5.0 Vdc
±
10%, V
SS
= 0 Vdc, T
A
= T
L
to T
H
)
Characteristic
Resolution
Non-linearity
Parameter
Mn
8
Max
—
Unit
Bit
Number of bits resolved by the A/D
Max deviation fromthe best straight line through the A/D
transfer characteristics
(V
RH
= V
DD
and V
RL
= 0V)
Uncertainty due to converter resolution
Difference between the actual input voltage and the
full-scale equivalent of the binary code output code for all
errors
Analog input voltage range
Maximumanalog reference voltage
Mnimumanalog reference voltage
Mnimumdifference between V
RH
and V
RL
Total time to performa single analog to digital conversion
a. External clock (OSC1, OSC2)
b. Internal RC oscillator
Conversion result never decreases with an increase in
input voltage and has no mssing codes
Conversion result when V
IN
= V
RL
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
—
±
0.5
LSB
Quantization error
Absolute accuracy
—
±
0.5
LSB
—
±
1
LSB
Conversion range
V
RH
V
RL
V
R(1)
Conversion time
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
Monotonicity
GUARANTEED
Zero input reading
Full scale reading
00
—
—
FF
Hex
Hex
—
—
—
—
12
12
t
CYC
s
pF
μ
A
12
1
TPG