PIC12CE67 Microchip Technology, PIC12CE67 Datasheet - Page 41

• Manufacturer Part Number: PIC12CE67
• Description: 8-Pin/ 8-Bit CMOS Microcontroller with A/D Converter and EEPROM Data Memory
• Manufacturer: Microchip Technology

8.2
The A/D conversion time per bit is defined as T
A/D conversion requires 9.5 T
The source of the A/D conversion clock is software
selected. The four possible options for T
For correct A/D conversions, the A/D conversion clock
(T
of 1.6 s.
Table 8-1 shows the resultant T
the device operating frequencies and the A/D clock
source selected.
TABLE 8-1:
Operation
2T
8T
32T
Internal ADC RC Oscillator
Note 1: The RC source has a typical T
AD
1998 Microchip Technology Inc.
OSC
OSC
• 2T
• 8T
• 32T
• Internal ADC 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: While in RC mode, with device frequency above 1 MHz, conversion accuracy is out of specification.
5: For extended voltage devices (LC), please refer to Electrical Specifications section.
Selecting the A/D Conversion Clock
OSC
OSC
OSC
AD Clock Source (T
T
AD
vs. DEVICE OPERATING FREQUENCIES
(5)
AD
AD
per 8-bit conversion.
times derived from
ADCS1:ADCS0
AD
)
AD
AD
00
01
10
11
are:
time of 4 s.
AD
AD
. The
time
Preliminary
AD
time.
2 - 6 s
500 ns
4 MHz
2.0 s
8.0 s
8.3
The ADCON1 and TRIS registers control the operation
of the A/D port pins. The port pins that are desired as
analog inputs must have their corresponding TRIS bits
set (input). If the TRIS bit is cleared (output), the digital
output level (V
The A/D operation is independent of the state of the
CHS2:CHS0 bits and the TRIS bits.
Note 1: When reading the port register, all pins
Note 2: Analog levels on any pin that is defined as
(1,4)
(2)
Configuring Analog Port Pins
configured as analog input channel 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 AN3:AN0
pins), may cause the input buffer to con-
sume current that is out of the devices
specification.
Device Frequency
OH
2 - 6 s
or V
1.25 MHz
25.6 s
1.6 s
6.4 s
PIC12CE67X
OL
) will be converted.
(1,4)
(3)
DS40181B-page 41
333.33 kHz
2 - 6 s
24 s
96 s
6 s
(3)
(3)
(1)