PIC16F877A-I/PT Microchip Technology Inc., PIC16F877A-I/PT Datasheet - Page 117

• Manufacturer Part Number: PIC16F877A-I/PT
• Description: 44 PIN, 7 KB FLASH, 368 RAM, 33 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F877A-I/PT

• A/d Inputs: 8-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 33
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 44-pin TQFP
• Programmable Memory: 14K Bytes
• Ram Size: 368 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

11.2
The A/D conversion time per bit is defined as T
A/D conversion requires a minimum 12T
conversion. The source of the A/D conversion clock is
software selected. The four possible options for T
are:
• 2T
• 8T
• 32T
• Internal A/D module RC oscillator (2-6 s)
TABLE 11-1:
11.3
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: The RC source has a typical T
2001 Microchip Technology Inc.
Note 1: When reading the port register, any pin
OSC
OSC
OSC
2: When the device frequencies are greater than 1 MHz, the RC A/D conversion clock source is only recom-
3: For extended voltage devices (LC), please refer to the Electrical Characteristics (Sections 15.1 and 15.2).
Selecting the A/D Conversion
Clock
Configuring Analog Port Pins
2: Analog levels on any pin that is defined as
mended for SLEEP operation.
configured as an 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 AN7:AN0
pins), may cause the input buffer to con-
sume current that is out of the device
specifications.
Operation
OH
RC
32T
2T
8T
(1, 2, 3)
or V
T
OSC
OSC
OSC
AD
OL
vs. MAXIMUM DEVICE OPERATING FREQUENCIES (STANDARD DEVICES (C))
) will be converted.
AD Clock Source (T
AD
AD
time of 4 s, but can vary between 2-6 s.
per 10-bit
AD
. The
AD
AD
ADCS1:ADCS0
)
00
01
10
11
For correct A/D conversions, the A/D conversion clock
(T
of 1.6 s.
Table 11-1 shows the resultant T
the device operating frequencies and the A/D clock
source selected.
AD
) must be selected to ensure a minimum T
Maximum Device Frequency
PIC16F87X
1.25 MHz
(Note 1)
20 MHz
AD
5 MHz
Max.
DS30292C-page 115
times derived from
AD
time