
Electrical Specifications
5V ADC Electrical Characteristics
MC68HC908LJ24/LK24 — Rev. 2.1
Data Sheet
Freescale Semiconductor
Electrical Specifications
443
24.12 5V ADC Electrical Characteristics
Table 24-10. 5V ADC Electrical Characteristics
Characteristic
Symbol
Min
Max
Unit
Notes
Supply voltage
VDDA
4.5
5.5
V
VDDA is an dedicated pin and
should be tied to VDD on the
PCB with proper decoupling.
Input range
VADIN
0
VDDA
V
VADIN ≤ VDDA
Resolution
BAD
10
bits
Absolute accuracy
AAD
—
± 1.5
LSB
Includes quantization.
±0.5 LSB = ±1 ADC count.
ADC internal clock
fADIC
32 k
2 M
Hz
tADIC = 1/fADIC
Conversion range
RAD
VREFL
VREFH
V
ADC voltage
reference high
VREFH
—
VDDA + 0.1
V
ADC voltage
reference low
VREFL
VSSA – 0.1
—V
VSSA is tied to VSS internally.
Conversion time
tADC
16
17
tADIC
cycles
Sample time
tADS
5—
tADIC
cycles
Monotonically
MAD
Guaranteed
Zero input reading
ZADI
000
001
HEX
VADIN = VREFL
Full-scale reading
FADI
3FC
3FF
HEX
VADIN = VREFH
Input capacitance
CADI
—
20
pF
Not tested.
Input impedance
RADI
20M
—
VREFH/VREFL
IVREF
—
1.6
mA
Not tested.