MC68HC05B6_13 Datasheet, PDF (277/302 Pages) Freescale Semiconductor, Inc – Microcontrollers

Table H-10 A/D characteristics for 3.3V operation
Preliminary ^{(VDD = 3.3 Vdc ± 10%, VSS = 0 Vdc, TA = –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
—
errors
Conversion range
Analog input voltage range
V_RL
V_RH
Maximum analog reference voltage
V_RL
Max
—
±1
±1
±2
V_RH
V_DD + 0.1
Unit
Bit
LSB
LSB
LSB
V
V
V_RL
Minimum analog reference voltage
V_SS – 0.1
V_RH
V
∆V_R
Minimum difference between V_RH and V_RL
3
—
V
Conversion time
Total time to perform a single analog to digital conversion
Preliminary ^{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
Internal RC oscillator⁽¹⁾
Sample/hold capacitance Input capacitance on PD0/AN0–PD7/AN7
Input leakage⁽²⁾
Input leakage on A/D pins PD0/AN0–PD7/AN7, VRL, VRH
—
32
µs
GUARANTEED
00
—
Hex
—
FF
Hex
—
12
µs
—
12
pF
—
1
µA
(1) Source impedances greater than 10kΩ will adversely affect internal charging time during input sampling.
(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).
Preliminary
14
MC68HC05B6
Rev. 4.1
MC68HC705B32
Freescale
H-27