MC68HC05B4 Datasheet, PDF (271/298 Pages) Motorola, Inc – High-density Complementary Metal Oxide Semiconductor (HCMOS) Microcomputer Unit

H.8
A/D converter characteristics
Preliminary ^{Table H-9 A/D characteristics for 5V operation}
(V_DD = 5.0 Vdc ± 10%, V_SS = 0 Vdc, T_A = –40 to +85°C)
Characteristic
Parameter
Min
Resolution
Number of bits resolved by the A/D
8
Non-linearity
Quantization error
Max deviation from the best straight line through the A/D
transfer characteristics
—
(V_RH = V_DD and V_RL = 0V)
Uncertainty due to converter resolution
—
Absolute accuracy
Difference between the actual input voltage and the
full-scale equivalent of the binary code output code for all —
Max
—
± 0.5
± 0.5
±1
Unit
Bit
LSB
LSB
LSB
errors
Conversion range
Analog input voltage range
V _RL
V_RH
V
V_RH
Maximum analog reference voltage
V _RL
V_DD + 0.1
V
Preliminary ^VRL
∆V_R
Conversion time
Minimum analog reference voltage
Minimum difference between V _RH and V_RL
Total time to perform a single analog to digital conversion
a. External clock (OSC1, OSC2)
b. Internal RC oscillator
Monotonicity
Conversion result never decreases with an increase in
input voltage and has no missing codes
Zero input reading
Full scale reading
Sample acquisition time
Conversion result when V_IN = V_RL
Conversion result when V_IN = V_RH
Analog input acquisition sampling
a. External clock (OSC1, OSC2)
b. Internal RC oscillator⁽¹⁾
Sample/holdcapacitance Input capacitance on PD0/AN0–PD7/AN7
V _SS – 0.1
V_RH
3
—
—
32
—
32
GUARANTEED
00
—
—
FF
—
12
—
12
—
12
V
V
t_CYC
µs
Hex
Hex
t_CYC
µs
pF
Input leakage⁽²⁾
Input leakage on A/D pins PD0/AN0–PD7/AN7,VRL,VRH —
1
µA
(1) Source impedances greater than 10kΩ will adversely affect internal charging time during input sampling.
Preliminary (2) 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 8-2).
14
MC68HC05B6
Rev. 4
MC68HC705B32
TPG
MOTOROLA
H-25