
2002 Microchip Technology Inc.
Preliminary
DS30485A-page 285
PIC18FXX39
TABLE 23-21: A/D CONVERTER CHARACTERISTICS: PIC18FXX39 (INDUSTRIAL, EXTENDED)
PIC18LFXX39 (INDUSTRIAL)
FIGURE 23-22:
A/D CONVERSION TIMING
Param
No.
Symbol
Characteristic
Min
Typ
Max
Units
Conditions
A01
NR
Resolution
—
10
bit
A03
EIL
Integral linearity error
—
<±1
LSb VREF = VDD = 5.0V
A04
EDL
Differential linearity error
—
<±1
LSb VREF = VDD = 5.0V
A05
EG
Gain error
—
<±1
LSb VREF = VDD = 5.0V
A06
EOFF
Offset error
—
<±1.5
LSb VREF = VDD = 5.0V
A10
—
Monotonicity
guaranteed(2)
—VSS
≤ VAIN ≤ VREF
A20
A20A
VREF
Reference Voltage
(VREFH – VREFL)
1.8V
3V
—
V
VDD < 3.0V
VDD
≥ 3.0V
A21
VREFH
Reference voltage High
AVSS
—AVDD + 0.3V
V
A22
VREFL
Reference voltage Low
AVSS – 0.3V
—
VREFH
V
A25
VAIN
Analog input voltage
AVSS – 0.3V
—
AVDD + 0.3V
V
VDD
≥ 2.5V (Note 3)
A30
ZAIN
Recommended impedance of
analog voltage source
——
2.5
k
(Note 4)
A50
IREF
VREF input current (Note 1)
—
5
150
A
During VAIN acquisition
During A/D conversion cycle
Note 1: Vss
≤ VAIN ≤ VREF
2: The A/D conversion result never decreases with an increase in the Input Voltage, and has no missing codes.
3: For VDD < 2.5V, VAIN should be limited to < .5 VDD.
4: Maximum allowed impedance for analog voltage source is 10 k
. This requires higher acquisition times.
131
130
132
BSF ADCON0, GO
Q4
A/D CLK
A/D DATA
ADRES
ADIF
GO
SAMPLE
OLD_DATA
SAMPLING STOPPED
DONE
NEW_DATA
(Note 2)
98
7
2
1
0
Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts.
This allows the SLEEP instruction to be executed.
2: This is a minimal RC delay (typically 100 ns), which also disconnects the holding capacitor from the analog input.
. . .
TCY