PIC16F1503T-I View Datasheet(PDF) - Microchip Technology
Part Name
Description
Manufacturer
PIC16F1503T-I Datasheet PDF : 352 Pages
| |||
PIC16(L)F1503
15.1 ADC Configuration
When configuring and using the ADC the following
functions must be considered:
• Port configuration
• Channel selection
• ADC voltage reference selection
• ADC conversion clock source
• Interrupt control
• Result formatting
15.1.1 PORT CONFIGURATION
The ADC can be used to convert both analog and
digital signals. When converting analog signals, the I/O
pin should be configured for analog by setting the
associated TRIS and ANSEL bits. Refer to Section
11.0 “I/O Ports” for more information.
Note:
Analog voltages on any pin that is defined
as a digital input may cause the input
buffer to conduct excess current.
15.1.2 CHANNEL SELECTION
There are 11 channel selections available:
• AN<7:0> pins
• Temperature Indicator
• FVR_buffer1
The CHS bits of the ADCON0 register determine which
channel is connected to the sample and hold circuit.
When changing channels, a delay (TACQ) is required
before starting the next conversion. Refer to Section
15.2.6 “ADC Conversion Procedure” for more infor-
mation.
15.1.3 ADC VOLTAGE REFERENCE
The ADC module uses a positive and a negative
voltage reference. The positive reference is labeled
ref+ and the negative reference is labeled ref-.
The positive voltage reference (ref+) is selected by the
ADPREF bits in the ADCON1 register. The positive
voltage reference source can be:
• VREF+ pin
• VDD
The negative voltage reference (ref-) source is:
• VSS
15.1.4 CONVERSION CLOCK
The source of the conversion clock is software select-
able via the ADCS bits of the ADCON1 register. There
are seven possible clock options:
• FOSC/2
• FOSC/4
• FOSC/8
• FOSC/16
• FOSC/32
• FOSC/64
• FRC (internal RC oscillator)
The time to complete one bit conversion is defined as
TAD. One full 10-bit conversion requires 11.5 TAD
periods as shown in Figure 15-2.
For correct conversion, the appropriate TAD specifica-
tion must be met. Refer to the ADC conversion require-
ments in Section 28.0 “Electrical Specifications” for
more information. Table 15-1 gives examples of
appropriate ADC clock selections.
Note:
Unless using the FRC, any changes in the
system clock frequency will change the
ADC clock frequency, which may
adversely affect the ADC result.
DS40001607D-page 114
2011-2015 Microchip Technology Inc.
Share Link: 