Microchip PIC16F688T-E/ST Microcontroller: Datasheet, Features, and Application Circuits
The Microchip PIC16F688T-E/ST is a high-performance, 8-bit microcontroller from Microchip Technology's extensive PIC® MCU family. Housed in a compact 14-pin TSSOP package, this device is engineered for applications requiring a robust set of peripherals in a minimal footprint. It is particularly suited for consumer, industrial, automotive, and low-power battery-operated applications.
Key Features and Specifications
At its core, the PIC16F688T-E/ST is built upon an enhanced mid-range PIC16 architecture with a 14-bit wide instruction set. It operates at a maximum frequency of 20 MHz, delivering 5 MIPS of performance. Its standout features include:
Memory: It boasts 4 KB of Flash program memory, 256 bytes of EEPROM data memory for storing non-volatile data, and 256 bytes of SRAM.
Analog Capabilities: A significant feature is its integrated 10-bit Analog-to-Digital Converter (ADC) with up to 11 input channels, allowing for extensive sensor interfacing. It also includes an analog comparator module.
Peripherals: The MCU is equipped with versatile peripherals such as two timers (Timer0 and Timer1), an Enhanced Capture/Compare/PWM (ECCP) module for motor control and power conversion, and a Master Synchronous Serial Port (MSSP) that can be configured for either I2C or SPI communication protocols.
Low-Power Operation: It supports nanoWatt technology, enabling extremely low-power consumption in various sleep modes, which is critical for portable and battery-powered devices.
Robust Oscillator Options: The controller features an internal 8 MHz oscillator with an internal PLL, allowing it to run at full speed without external crystal components, reducing both board space and cost.
Datasheet Overview
The official datasheet is the ultimate design resource. It provides complete electrical characteristics, timing diagrams, register maps, and packaging information. Key sections to review before design-in include:
Absolute Maximum Ratings: Understanding voltage, temperature, and current limits.
DC/AC Characteristics: Detailed specifications for ADC accuracy, oscillator parameters, and pin input/output levels.
Core and Peripheral Functionality: In-depth explanations of how to configure and use the ADC, ECCP, comparators, and communication modules.
Programming Specifications: Guidelines for in-circuit serial programming (ICSP).
Application Circuits
The versatility of the PIC16F688T-E/ST enables its use in a vast array of circuits. Here are two common examples:
1. Temperature Data Logger:
This application leverages the MCU's ADC and EEPROM. A temperature sensor (e.g., thermistor or analog output IC like TC1047A) is connected to an ADC input pin. The MCU periodically reads the analog voltage, converts it to a digital value, and stores it in its internal EEPROM. The stored data can later be transmitted to a PC via a serial interface (e.g., using the USART and an external level translator like MAX232).
2. LED Dimming Controller (PWM):
Utilizing the Enhanced CCP module, the microcontroller can generate a Pulse-Width Modulated (PWM) signal. This signal is fed to a MOSFET or a dedicated LED driver IC to control the power delivered to a high-power LED. The duty cycle of the PWM wave, and hence the LED's brightness, can be adjusted via a potentiometer connected to another ADC input, creating a closed-loop control system.
The Microchip PIC16F688T-E/ST stands out as an exceptionally capable 8-bit microcontroller, packing a powerful combination of analog integration, communication peripherals, and low-power operation into a tiny 14-pin package. Its balance of performance, features, and cost makes it an ideal choice for space-constrained and power-sensitive designs across numerous markets.
Keywords:
PIC16F688
Microcontroller
Analog-to-Digital Converter (ADC)
Low-Power
TSSOP
