Intel MCS48 User Manual page 192

8022
A/D CONVERTER
CHARACTERISTICS
T A
=0°C
to
70°C,
V
C c=5.5V
±
1V,
V
S
s=0V,
AVcc=5.5V
±
1V,
AV
S
s=0V,
MqqI2
<
V
A REF
^
AV
Cc
Parameter
Min. Typ. Max.
Unit
Comments
Resolution 8
Bits
Switch
Point
Accuracy
±Vs
LSB
(Note
1)
Absolute Accuracy
±1
LSB
Sample
Setup Before
Falling
Edge
of
ALE
(tss)
0.20
tCY
(Note
2)
Sample
Hold
After Falling
Edge
of
ALE
Osh)
0.10
*CY
(Note
2)
Input
Capacitance
(ANO,
AN1)
1
PF
Conversion Time 4
4
*CY
Z
j
'
IDEAL TRANSITION
.
SWITCH
POINT
ACCURACY
I
itt
I
2
3
253 254
!56
256 256 256
ANALOG
INPUT (OF FUU- SCALE)
ANALOG
INPUT TIMING
/
X
\
X
r
NOTES:
1.
The Switch
Point
Accuracy measures
the
variation of
the actual switch points from the transitions of
an
ideal
A/D
converter over the
full
conversion range.
2.
The
analog input
must be maintained
at
a constant voltage during the
sample time
(t ss
+
t SH
).
6-40