PIC18F86J72-I/PT Microchip Technology, PIC18F86J72-I/PT Datasheet - Page 313

• Manufacturer Part Number: PIC18F86J72-I/PT
• Description: IC PIC MCU 8BIT 14KB FLSH 80TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F86J72-I/PT

• Program Memory Type: FLASH
• Program Memory Size: 64KB (32K x 16)
• Package / Case: 80-TQFP
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, LVD, POR, PWM, WDT
• Number Of I /o: 51
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 12x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, USART, SPI, I2C
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 51
• Number Of Timers: 4
• Operating Supply Voltage: 2 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 14
• Controller Family/series: PIC18F
• No. Of I/o's: 51
• Ram Memory Size: 3923Byte
• Cpu Speed: 12MIPS
• No. Of Timers: 4
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

25.5
Time can be precisely measured after the ratio (C/I) is
measured from the current and capacitance calibration
step by following these steps:
1.
2.
3.
4.
5.
FIGURE 25-3:
 2010 Microchip Technology Inc.
Initialize the A/D Converter and the CTMU.
Set EDG1STAT.
Set EDG2STAT.
Perform an A/D conversion.
Calculate the time between edges as T = (C/I) * V,
where I is calculated in the current calibration step
(Section 25.3.1 “Current Source Calibration”),
C is calculated in the capacitance calibration step
(Section 25.3.2 “Capacitance Calibration”) and
V is measured by performing the A/D conversion.
Measuring Time with the CTMU
Module
TYPICAL CONNECTIONS AND INTERNAL CONFIGURATION FOR TIME
MEASUREMENT
CTEDG1
CTEDG2
AN
R
PR
X
Preliminary
PIC18F87J72 FAMILY
EDG2
It is assumed that the time measured is small enough
that the capacitance C
the A/D Converter. For the smallest time measurement,
always set the A/D Channel Select register (AD1CHS)
to an unused A/D channel; the corresponding pin for
which is not connected to any circuit board trace. This
minimizes added stray capacitance, keeping the total
circuit capacitance close to that of the A/D Converter
itself (25 pF). To measure longer time intervals, an
external capacitor may be connected to an A/D
channel, and this channel selected when making a time
measurement.
EDG1
C
AD
A/D Converter
PIC18F87J72
Current Source
CTMU
Output Pulse
OFFSET
provides a valid voltage to
DS39979A-page 313