PIC16C63A Microchip Technology, PIC16C63A Datasheet - Page 79

• Manufacturer Part Number: PIC16C63A
• Description: 28/40-Pin 8-Bit CMOS Microcontrollers
• Manufacturer: Microchip Technology

10.2
The A/D conversion time per bit is defined as T
A/D conversion requires 9.5T
The source of the A/D conversion clock is software
selectable. The four possible options for T
For correct A/D conversions, the A/D conversion clock
(T
of 1.6 s.
Table 10-1 shows the resultant T
the device operating frequencies and the A/D clock
source selected.
TABLE 10-1:
Operation
2T
8T
32T
RC
Legend: Shaded cells are outside of recommended range.
Note 1: The RC source has a typical T
AD
1998 Microchip Technology Inc.
OSC
OSC
(5)
• 2T
• 8T
• 32T
• Internal RC oscillator
) must be selected to ensure a minimum T
OSC
2: These values violate the minimum required T
3: For faster conversion times, the selection of another clock source is recommended.
4: When device frequency is greater than 1 MHz, the RC A/D conversion clock source is recommended for
5: For extended voltage devices (LC), please refer to Electrical Specifications section.
AD Clock Source (T
Selecting the A/D Conversion Clock
OSC
OSC
sleep operation only.
OSC
T
AD
ADCS1:ADCS0
vs. DEVICE OPERATING FREQUENCIES
00
01
10
11
AD
AD
)
AD
per 8-bit conversion.
times derived from
AD
AD
2 - 6 s
time of 4 s.
are:
100 ns
400 ns
20 MHz
1.6 s
AD
AD
. The
time
(1,4)
(2)
(2)
PIC16C63A/65B/73B/74B
AD
time.
2 - 6 s
10.3
The ADCON1, TRISA, and TRISE registers control the
operation of the A/D port pins. The port pins that are
desired as analog inputs must have their correspond-
ing TRIS bits set (input). If the TRIS bit is cleared (out-
put), the digital output level (V
converted.
The A/D operation is independent of the state of the
CHS2:CHS0 bits and the TRIS bits.
400 ns
5 MHz
1.6 s
6.4 s
Note 1: When reading the port register, all pins
Note 2: Analog levels on any pin that is defined as
Device Frequency
(1,4)
(2)
Configuring Analog Port Pins
configured as analog input channels will
read as cleared (a low level). Pins config-
ured as digital inputs, will convert an ana-
log input. Analog levels on a digitally
configured input will not affect the conver-
sion accuracy.
a digital input (including the AN4:AN0
pins) may cause the input buffer to con-
sume current that is out of the devices
specification.
2 - 6 s
1.25 MHz
25.6 s
1.6 s
6.4 s
(1,4)
(3)
OH
DS30605A-page 79
or V
333.33 kHz
2 - 6 s
24 s
96 s
6 s
OL
) will be
(3)
(3)
(1)