Datasheet

Analog-to-Digital Converter (ADC) Characteristics
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
Freescale Semiconductor 191
17.10 Analog-to-Digital Converter (ADC) Characteristics
Characteristic Symbol Min Max Unit Notes
Supply voltage
V
DD
2.7 5.5 V
Input voltages
V
ADIN
0
V
DD
V
Resolution
B
AD
88 Bits
Absolute accuracy
(1), (2)
1. One count is 1/256 of V
DD
.
2. V
REFH
is shared with V
DD
. V
REFL
is shared with V
SS
.
A
AD
–2.5 +2.5 Counts 8 bits = 256 counts
ADC clock rate
f
ADIC
500 k 1.048 M Hz
t
AIC
= 1/f
ADIC,
Tested only at 1 MHz
Conversion range
R
AD
V
SS
V
DD
V
Power-up time
t
ADPU
16 —
t
AIC
cycles
Conversion time
t
ADC
16 17
t
AIC
cycles
Sample time
t
ADS
5—
t
AIC
cycles
Monotocity
M
AD
Guaranteed
Zero input reading
Z
ADI
00 — Hex V
In
= V
SS
Full-scale reading
F
ADI
—FF Hex
V
In
= V
DD
Input capacitance
C
ADI
— 20 pF Not tested