Instrukcja obsługi Microchip PIC18F26K83

Microchip nieskategoryzowany PIC18F26K83

Przeczytaj poniżej 📖 instrukcję obsługi w języku polskim dla Microchip PIC18F26K83 (27 stron) w kategorii nieskategoryzowany. Ta instrukcja była pomocna dla 7 osób i została oceniona przez 2 użytkowników na średnio 4.5 gwiazdek

Pobierz PDF
Strona 1/27
TB3194
PIC16/PIC18 ADC² Technical Brief
Introduction
Author: Christopher Best, Microchip Technology Inc.
An Analog-to-Digital Converter (ADC) converts an analog input signal into a digital number representing
the magnitude of the input voltage. Microchip’s 12-bit ADC with Computation (ADC 2) outputs a 12-bit
binary representation of the original signal and adds special hardware features to provide post-processing
functions that can be performed on the conversion result.
This technical brief provides an overview of the basic ADC features and functions, and describes the
additional computation features that are not found in other ADC modules. This document will not cover
the Capacitive Voltage Divider (CVD) feature, which is covered in TB3198, but may refer to CVD in
general terms. This technical brief will cover the ADC2 module found in Microchip’s PIC16 and PIC18 8-
bit architecture.
© 2018 Microchip Technology Inc. 90003194A-page 1
Table of Contents
Introduction......................................................................................................................1
1. ADC Module Overview.............................................................................................. 3
1.1. ADC Block.................................................................................................................................... 3
1.1.1. ADC Inputs.................................................................................................................... 3
1.1.2. ADC Voltage Reference.................................................................................................5
1.1.3. ADC Charge Pump........................................................................................................ 6
1.1.4. ADC Conversion Clock.................................................................................................. 6
1.1.5. Continuous Sampling Mode...........................................................................................7
1.1.6. Double Sample Conversion Mode.................................................................................8
1.1.7. Auto-Conversion Trigger................................................................................................8
1.1.8. Conversion Result Formatting....................................................................................... 8
1.1.9. ADC Conversion Interrupt..............................................................................................9
1.1.10. Sleep Mode....................................................................................................................9
1.2. Computation............................................................................................................................... 10
1.2.1. Basic Mode.................................................................................................................. 10
1.2.2. Accumulate Mode........................................................................................................ 10
1.2.3. Average Mode..............................................................................................................11
1.2.4. Burst Average Mode.................................................................................................... 11
1.2.5. Low-Pass Filter Mode.................................................................................................. 12
1.3. Threshold Comparison............................................................................................................... 17
2. Conclusion...............................................................................................................20
3. Appendix A: Basic Analog Terminology...................................................................21
The Microchip Web Site................................................................................................ 24
Customer Change Notification Service..........................................................................24
Customer Support......................................................................................................... 24
Microchip Devices Code Protection Feature................................................................. 24
Legal Notice...................................................................................................................25
Trademarks................................................................................................................... 25
Quality Management System Certified by DNV.............................................................26
Worldwide Sales and Service........................................................................................27
TB3194
© 2018 Microchip Technology Inc. 90003194A-page 2
1. ADC Module Overview
The ADC2 module consists of two main blocks: the acquisition/conversion block (ADC) and the
computation block. The ADC block reads an analog signal and converts it into a digital number, while the
computation block takes the converted digital number and applies post-processing functions.
The ADC block provides the following features:
• 13-bit Acquisition Timer
• Automatic Repeat and Sequencing:
– Two result registers
– Auto-conversion trigger
– Automated double sample conversion for CVD
• Hardware Capacitive Voltage Divider (CVD) Support:
– 13-bit Precharge Timer
– Adjustable sampling capacitor array
– Guard ring digital output drive
The Computation block provides the following features:
• Averaging and Low-Pass Filter Functions
• Reference Comparison
• 2-level Threshold Comparison
• Selectable Interrupts
1.1 ADC Block
The ADC block contains all the circuitry needed to convert an analog input signal into a digital
representation of that signal. Analog input channels are multiplexed into the converter’s single sampling
circuit. The converter’s sampling circuit generates a 12-bit binary result via successive approximation and
stores the conversion result into the ADC result registers.
1.1.1 ADC Inputs
The ADC can be used to convert both analog and digital signals. The signals may come from external
sources via a port pin, or from internal sources. The ADC Positive Channel Selection (ADPCH) register
controls the input multiplexer and determines which analog input channel is connected to the sampling
circuit.
There may be several external input channels depending on the pin count of the selected device, but only
one channel, either internal or external, can be selected and converted at a time. To determine the
number and location of ADC channels in any PIC® device, refer to the specific device data sheet. Many
data sheets list the location of each channel in the ‘Pin Diagrams’ charts. Each external channel is
labeled ‘ANxy’, where ‘x’ refers to the I/O port, and ‘y’ refers to the pin within the port. For example, an
external input signal, ANA1, points to the analog channel of PORTA, pin one.
Older data sheets, or data sheets for low pin count devices may label each external channel simply as
‘ANx’, where ‘x’ is the input channel number and may or may not refer to the actual port pin. For example,
a 16-lead device may use the label AN1, but AN1 may point to PORTA’s pin number two.
When converting an analog input signal, the I/O pin must be configured as an input by setting the port
pin’s TRIS bit corresponding to the selected input channel. Additionally, the pin must be configured as an
TB3194
ADC Module Overview
© 2018 Microchip Technology Inc. 90003194A-page 3

Specyfikacje produktu

Marka: Microchip
Kategoria: nieskategoryzowany
Model: PIC18F26K83

Potrzebujesz pomocy?

Jeśli potrzebujesz pomocy z Microchip PIC18F26K83, zadaj pytanie poniżej, a inni użytkownicy Ci odpowiedzą


Instrukcje nieskategoryzowany Microchip

Microchip

Microchip EMC1824 Instrukcja

5 Lipca 2024
Microchip

Microchip EVB-USB3740 Instrukcja

5 Lipca 2024
Microchip

Microchip EVB-USB3503 Instrukcja

5 Lipca 2024
Microchip

Microchip EVB-LAN7430 Instrukcja

5 Lipca 2024
Microchip

Microchip ATSAMHA1G14A-B Instrukcja

5 Lipca 2024
Microchip

Microchip MCP1631 Instrukcja

5 Lipca 2024
Microchip

Microchip ATSAM4LS4B Instrukcja

5 Lipca 2024
Microchip

Microchip EVB-USB2507 Instrukcja

5 Lipca 2024
Microchip

Microchip EVB-USB2502 Instrukcja

5 Lipca 2024
Microchip

Microchip PAC1710 Instrukcja

5 Lipca 2024

Instrukcje nieskategoryzowany

Najnowsze instrukcje dla nieskategoryzowany

Meec Tools

Meec Tools 010-084 Instrukcja

6 Października 2024
Outwell

Outwell Scenic Road 250 Instrukcja

5 Października 2024
Impact

Impact Qualite QL-3560-LED Instrukcja

4 Października 2024
Impact

Impact QuikBalance Instrukcja

4 Października 2024
Impact

Impact CA-112 Instrukcja

4 Października 2024
Impact

Impact Forever Ready Cool FRC-24-LED Instrukcja

4 Października 2024
Impact

Impact LS-BHA Instrukcja

4 Października 2024
Impact

Impact LKB-5C Instrukcja

4 Października 2024
Impact

Impact Varipole Drop Ceiling Adapter Instrukcja

4 Października 2024
Impact

Impact RST-001 Instrukcja

4 Października 2024