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MC68HC05X16 Datasheet, PDF (181/232 Pages) Freescale Semiconductor, Inc – High-density complementary metal oxide semiconductor HCMOS) microcontroller unit | |||
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Freescale Semiconductor, Inc.
A.3.3 A/D converter characteristics
Table A-4 A/D characteristics
(VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = â40°C to +125°C)
Characteristic
Parameter
Min
Max
Unit
Resolution
Number of bits resolved by the A/D
8
â
Bit
Non-linearity
Quantization error
Max deviation from the best straight line through the A/D
transfer characteristics
â
(VRH = VDD and VRL = 0V)
Uncertainty due to converter resolution
â
± 0.5
LSB
± 0.5
LSB
Absolute accuracy
Difference between the actual input voltage and the
full-scale equivalent of the binary code output code for all
â
errors
±1
LSB
Conversion range
VRH
VRL
âVR(1)
Conversion time
Analog input voltage range
VRL
VRH
V
Maximum analog reference voltage
VRL
VDD + 0.1
V
Minimum analog reference voltage
VSS â 0.1
VRH
V
Minimum difference between VRH and VRL
3
â
V
Total time to perform a single analog to digital conversion
a. External clock (OSC1, OSC2)
b. Internal RC oscillator
â
32
tCYC
â
32
µs
Monotonicity
Conversion result never decreases with an increase in
input voltage and has no missing codes
GUARANTEED
Zero input reading
Full scale reading
Sample acquisition time
Conversion result when VIN = VRL
Conversion result when VIN = VRH
Analog input acquisition sampling
a. External clock (OSC1, OSC2)
b. Internal RC oscillator(2)
00
â
Hex
â
FF
Hex
â
12
tCYC
â
12
µs
Sample/hold capacitance Input capacitance on PD0/AN0âPD7/AN7
â
Input leakage(3)
Input leakage on A/D pins PD0/AN0âPD7/AN7, VRL, VRH â
12
pF
1
µA
(1) Performance veriï¬ed down to 2.5V âVR, but accuracy is tested and guaranteed at âVR = 5V±10%.
(2) Source impedances greater than 10k⦠will adversely affect internal charging time during input sampling.
(3) The external system error caused by input leakage current is approximately equal to the product of R source and input
current. Input current to A/D channel will be dependent on external source impedance (see Figure 9-2).
MC68HC05X16
MC68HC05X32
For More Information On This Product,
Go to: www.freescale.com
15
A-9
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