Datasheet

MC68HC908JL3E Family Data Sheet, Rev. 4
162 Freescale Semiconductor
A.5.5 ADC Characteristics
Table A-5. ADC Characteristics
Characteristic Symbol Min Max Unit Comments
Supply voltage
V
DDAD
2.2
(V
DD
min)
5.5
(V
DD
max)
V
Input voltages
V
ADIN
V
SS
V
DD
V
Resolution
B
AD
88Bits
Absolute accuracy
A
AD
± 0.5 ± 2 LSB Includes quantization
ADC internal clock
f
ADIC
0.5 1.048 MHz
t
AIC
= 1/f
ADIC
, tested
only at 1 MHz
Conversion range
R
AD
V
SS
V
DD
V
Power-up time
t
ADPU
14 —
t
AIC
cycles
Conversion time
t
ADC
14 15
t
AIC
cycles
Sample time
(1)
1. Source impedances greater than 10 kΩ adversely affect internal RC charging time during input sampling.
t
ADS
5—
t
AIC
cycles
Zero input reading
(2)
2. Zero-input/full-scale reading requires sufficient decoupling measures for accurate conversions.
Z
ADI
00 01 Hex
V
IN
= V
SS
Full-scale reading
(3)
F
ADI
FE FF Hex
V
IN
= V
DD
Input capacitance
C
ADI
— (20) 8 pF Not tested
Input leakage
(3)
Port B/port D
3. The external system error caused by input leakage current is approximately equal to the product of R source and input
current.
—— ± 1 μA