Datasheet

Electrical Specifications
Technical Data MC68HC908LJ12 — Rev. 2.1
400 Electrical Specifications Freescale Semiconductor
23.13 3.3V ADC Electrical Characteristics
Table 23-11. ADC 3.3V Electrical Characteristics
Characteristic Symbol Min Max Unit Notes
Supply voltage
V
DDA
3.0 3.6 V
V
DDA
is an dedicated pin and
should be tied to V
DD
on the
PCB with proper decoupling.
Input range
V
ADIN
0
V
DDA
V
V
ADIN
≤ V
DDA
Resolution
B
AD
10 10 bits
Absolute accuracy
A
AD
— ± 1.5 LSB
Includes quantization.
±0.5 LSB = ±1 ADC count.
ADC internal clock
f
ADIC
32 k 2 M Hz
t
ADIC
= 1/f
ADIC
Conversion range
R
AD
V
REFL
V
REFH
V
ADC voltage
reference high
V
REFH
—
V
DDA
+ 0.1
V
ADC voltage
reference low
V
REFL
V
SSA
– 0.1
—V
V
SSA
is tied to V
SS
internally.
Conversion time
t
ADC
16 17
t
ADIC
cycles
Sample time
t
ADS
5—
t
ADIC
cycles
Monotonically
M
AD
Guaranteed
Zero input reading
Z
ADI
000 001 HEX
V
ADIN
= V
REFL
Full-scale reading
F
ADI
3FC 3FF HEX
V
ADIN
= V
REFH
Input capacitance
C
ADI
— 20 pF Not tested.
Input impedance
R
ADI
20M — Ω Measured at 5V
V
REFH
/V
REFL
I
VREF
— 1.6 mA Not tested.