PIC16F874A-E/PT - 8-bit MCU, 7KB Flash, 44-TQFP | Microchip
MPN： PIC16F874A-E/PT ✓ 啟用中PIC16F874A-E/PT 概覽
A PIC microcontroller is a RISC-based 8-bit (or 16/32-bit) microcontroller family built around Harvard architecture, widely adopted in embedded designs for its deterministic instruction timing, low cost, and rich peripheral integration. The PIC16F sub-family sits between the baseline PIC10/12/16 and the high-performance PIC18/PIC24 families, offering self-programmability, hardware USART, and EEPROM data memory - a common architecture choice for industrial control, consumer appliances, and legacy communications equipment.
Key features of the PIC16F874A include a 14-bit instruction word, 35 single-word instructions, ICD (In-Circuit Debug) support, and a brown-out detect circuit. The 10-bit ADC with 8 input channels makes the part suitable for sensor-conditioning applications, while two analog comparators enable feedback control loops without external op-amps. The 25 mA source/sink per I/O pin is unusually strong for an MCU, allowing direct LED or small-relay drive without buffering transistors.
The architecture separates program and data buses (Harvard), and the 20 MHz oscillator (8-bit) drives an internal 4-phase clock with 200 ns instruction execution. A 14-bit program counter reaches up to 8K words of Flash; the device boots into user mode and supports self-programming through a dedicated routine. The enhanced PIC16F874A silicon incorporates nanoWatt technology options that gate unused peripherals to lower quiescent current, an important consideration for battery-backed designs.
Typical applications include industrial sensor conditioning, HVAC control boards, security alarm panels, automotive body electronics (non-safety), small appliances, and educational embedded platforms where the PIC16F877A and PIC16F874A are interchangeable via the same datasheet family. The PIC16F874A variant without the suffix-A is functionally compatible but lacks the nanoWatt improvements.
When designing with this MCU, ensure the in-circuit serial programming (ICSP) pins are accessible on the PCB for firmware updates. The 44-pin TQFP footprint provides access to all 33 I/O pins and the full peripheral set; pair it with a regulated 5 V rail and a decoupling capacitor on each VDD/VSS pair per the datasheet layout guidelines. The PIC16F874A datasheet family documents both 40-pin DIP and 44-pin TQFP variants; the PIC16F874A-E/PT temperature grade (-40C to +125C) supports extended industrial environments.
直接替換替代品，適用於 PIC16F874A-E/PT — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： PIC16F874A-E/PT （相同外形與佔位） — 差異在於 Package, Operating Temperature, Timers, Core Architecture, Program Memory (Flash).
PIC16F877A-E/PT
✅ 直接替換聯絡詢價
查看資料表 →PIC16F874-04E/PT
✅ 直接替換聯絡詢價
查看資料表 →PIC16F874-10E/PT
✅ 直接替換聯絡詢價
查看資料表 →PIC16F874A-I/PT
✅ 直接替換📋 參考替代品（不在目錄中）
PIC18F4520-I/PT
✅ 直接替換聯絡詢價
查看資料表 →PIC18F4580-I/PT
✅ 直接替換📋 參考替代品（不在目錄中）
PIC16F874A-E/PT 最大額定值與電氣特性
| Family | PIC16F (PIC 8-bit) |
| Core Architecture | RISC, Harvard, 8-bit |
| Instruction Set | 35 single-word instructions |
| Program Memory (Flash) | 7 KB (4K x 14 words) |
| Data RAM | 192 bytes |
| EEPROM Data Memory | 128 bytes |
| Maximum CPU Frequency | 20 MHz |
| Instruction Execution Time | 200 ns |
| ADC | 10-bit, 8 channels |
| Comparators | 2 analog comparators |
| Capture/Compare/PWM Modules | 2 CCP |
| Serial Interfaces | 1x USART, 1x MSSP (SPI / I2C) |
| I/O Pins | 33 (5 ports) |
| I/O Sink/Source | 25 mA per pin |
| Operating Voltage | 4.0 V to 5.5 V |
| Operating Temperature (E suffix) | -40C to +125C (extended) |
| 封裝 | 44-pin TQFP (PT), 10x10 mm |
| 安裝類型 | Surface Mount |
| Self-Programming | Yes (Flash) |
| In-Circuit Debug | Yes (ICD) |
| Brown-out Reset | Yes (BOR) |
| Watchdog Timer | Yes (WDT) |
| MSL 等級 | 3 (per JEDEC J-STD-020) |
| RoHS 狀態 | Compliant |
| AEC-Q100 | Not qualified |
PIC16F874A-E/PT 腳位配置
| 腳位 1 | VSS — Ground reference |
| 腳位 2 | RA0/AN0 — PORTA bit 0 / ADC input channel 0 |
| 腳位 3 | RA1/AN1 — PORTA bit 1 / ADC input channel 1 |
| 腳位 4 | RA2/AN2/VREF- — PORTA bit 2 / ADC input channel 2 / VREF- |
| 腳位 5 | RA3/AN3/VREF+ — PORTA bit 3 / ADC input channel 3 / VREF+ |
| 腳位 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| 腳位 7 | RA5/AN4/SS — PORTA bit 5 / ADC input channel 4 / SPI slave select |
| 腳位 8 | RE0/RD/AN5 — PORTE bit 0 / Read control for parallel slave port / ADC ch5 |
| 腳位 9 | RE1/WR/AN6 — PORTE bit 1 / Write control for PSP / ADC ch6 |
| 腳位 10 | RE2/CS/AN7 — PORTE bit 2 / Chip select for PSP / ADC ch7 |
| 腳位 11 | VDD — Positive supply (4.0V to 5.5V) |
| 腳位 12 | VSS — Ground reference |
| 腳位 13 | OSC1/CLKIN — Oscillator input / external clock in |
| 腳位 14 | OSC2/CLKOUT — Oscillator output / clock out (Fosc/4) |
| 腳位 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator out / T1 clock in |
| 腳位 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator in / CCP2 I/O |
| 腳位 17 | RC2/CCP1 — PORTC bit 2 / CCP1 I/O |
| 腳位 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| 腳位 19 | RD0/PSP0 — PORTD bit 0 / Parallel slave port bit 0 |
| 腳位 20 | RD1/PSP1 — PORTD bit 1 / Parallel slave port bit 1 |
| 腳位 21 | RD2/PSP2 — PORTD bit 2 / Parallel slave port bit 2 |
| 腳位 22 | RD3/PSP3 — PORTD bit 3 / Parallel slave port bit 3 |
| 腳位 23 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| 腳位 24 | RC5/SDO — PORTC bit 5 / SPI data out |
| 腳位 25 | RC6/TX/CK — PORTC bit 6 / USART async transmit / sync clock |
| 腳位 26 | RC7/RX/DT — PORTC bit 7 / USART async receive / sync data |
| 腳位 27 | RD4/PSP4 — PORTD bit 4 / Parallel slave port bit 4 |
| 腳位 28 | RD5/PSP5 — PORTD bit 5 / Parallel slave port bit 5 |
| 腳位 29 | RD6/PSP6 — PORTD bit 6 / Parallel slave port bit 6 |
| 腳位 30 | RD7/PSP7 — PORTD bit 7 / Parallel slave port bit 7 |
| 腳位 31 | VSS — Ground reference |
| 腳位 32 | VDD — Positive supply (4.0V to 5.5V) |
| 腳位 33 | RB0/INT — PORTB bit 0 / External interrupt input |
| 腳位 34 | RB1 — PORTB bit 1 |
| 腳位 35 | RB2 — PORTB bit 2 |
| 腳位 36 | RB3/PGM — PORTB bit 3 / Low-voltage ICSP programming |
| 腳位 37 | RB4 — PORTB bit 4 |
| 腳位 38 | RB5 — PORTB bit 5 |
| 腳位 39 | RB6/PGC — PORTB bit 6 / ICSP clock input |
| 腳位 40 | RB7/PGD — PORTB bit 7 / ICSP data input/output |
| 腳位 41 | VSS — Ground reference |
| 腳位 42 | VDD — Positive supply (4.0V to 5.5V) |
| 腳位 43 | NC — Not connected (per datasheet) |
| 腳位 44 | NC — Not connected (per datasheet) |
典型應用
PIC16F874A-E/PT 適用於 6 應用s: Industrial Sensor Conditioning, HVAC Control Boards, Security and Alarm Panels, Automotive Body Electronics (non-safety), Small Appliance Control, Educational Embedded Platforms.
Industrial Sensor Conditioning
The PIC16F874A-E/PT is an excellent fit for multi-signal industrial sensor conditioning thanks to its integrated 10-bit 8-channel ADC, two analog comparators for threshold detection, and 25 mA I/O drive for direct sensor biasing or relay control. Operating at 20 MHz (200 ns instruction execution), it can sample and filter up to 8 analog channels while servicing the USART and SPI/I2C interfaces for HMI or PLC networking. The 128-byte EEPROM stores calibration data without external memory, and the brown-out reset plus watchdog timer protect against industrial line transients. The -40C to +125C extended temperature grade allows deployment inside unconditioned factory cabinets.
推薦
HVAC Control Boards
The PIC16F874A-E/PT powers HVAC control boards with its CCP modules generating PWM for fan/blower motor speed control, while the 10-bit ADC reads thermistor temperature inputs from supply/return air ducts. The PIC16F877A-E/PT shares the same TQFP-44 footprint and offers 2x Flash for more complex PID control loops. Two analog comparators handle line-voltage zero-crossing detection for triac firing, and the 25 mA sink/source directly drives relays and LED indicators. The extended -40C to +125C temperature range supports rooftop and outdoor HVAC unit deployment.
推薦
Security and Alarm Panels
The PIC16F874A-E/PT is a proven fit for security alarm panels, where its 8-channel 10-bit ADC reads multiple PIR motion sensors and smoke-detector outputs while the EEPROM stores user-configurable zone delays and entry/exit codes. The MSSP peripheral drives an I2C keypad scanner and an SPI slave connection to a GSM dialer module. The 192-byte RAM is sufficient for an event log of 30-40 entries; the brown-out reset preserves timekeeping during brief power glitches. The -40C to +125C extended temperature grade supports garages, basements, and outdoor alarm enclosures.
推薦
Automotive Body Electronics (non-safety)
The PIC16F874A-E/PT handles non-safety automotive body electronics such as seat controllers, mirror adjusters, ambient lighting, and rear-seat reminder modules, where the 8-bit PIC core and 20 MHz speed are sufficient for relay sequencing and LIN-style UART communication. The two CCP modules drive proportional LED dimming and the analog comparators monitor switch contact bounce. While the part itself is not AEC-Q100 qualified, the E temperature grade (-40C to +125C) covers under-dash cabin electronics. The 128-byte EEPROM stores user-preset seat/mirror positions reliably for the life of the vehicle.
推薦
Small Appliance Control
The PIC16F874A-E/PT drives small appliances like coffee machines, washing machine front panels, and microwave ovens, where the integrated 8-channel ADC reads temperature probes and water-level sensors while the two CCP modules control triac-firing for heating elements. The MSSP runs an I2C interface to character LCD displays and capacitive touch controllers; the USART enables Wi-Fi module integration on connected appliances. The 7 KB Flash holds a real-time state machine plus user interface menus; the 128-byte EEPROM stores favorite brewing recipes.
推薦
Educational Embedded Platforms
The PIC16F874A-E/PT is a popular choice in university embedded systems courses and hobbyist training kits because the PIC16F instruction set is small (35 instructions), deterministic, and well documented in textbooks from Mazidi, Bates, and Peatman. The 44-pin TQFP package exposes all peripherals on breakout boards while leaving room for header pins. The in-circuit debugger (ICD) support allows students to single-step through code without expensive tools. The 7 KB Flash comfortably fits introductory C/assembly projects using the PICkit 3 or PICkit 4 programmer.
推薦
推薦產品摘要
工程參考資料，適用於 PIC16F874A-E/PT — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | PIC16F877A-E/PT | PIC16F874-04E/PT | PIC18F4520-I/PT | PIC18F4580-I/PT |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin TQFP (PT) | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same |
| Architecture | PIC16 (8-bit) | PIC16 (8-bit) | PIC16 (8-bit) | PIC18 (8-bit enhanced) | PIC18 (8-bit enhanced) |
| Max CPU Frequency | 20 MHz | 20 MHz | 4 MHz | 40 MHz | 40 MHz |
| Flash Program Memory | 7 KB | 14 KB | 4 KB | 32 KB | 48 KB |
| Data RAM | 192 bytes | 368 bytes | 192 bytes | 1536 bytes | 3328 bytes |
| EEPROM | 128 bytes | 256 bytes | 64 bytes | 256 bytes | 1024 bytes |
| ADC | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 13 channels | 10-bit, 8 channels |
| Temperature Range (E suffix) | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +85C (I suffix) | -40C to +85C (I suffix) |
主要差異化特點
- Highest upgrade headroom in same footprint (對比PIC16F874-04E/PT)
- Same package, larger memory (對比PIC16F877A-E/PT)
- Simpler instruction set, easier C/asm (對比PIC18F4520-I/PT)
設計說明
Estimated: At 20 MHz with all peripherals active, the PIC16F874A core current is approximately 10 mA. Add a 100 nF decoupling capacitor on each VDD pin (pins 11, 32, 42) and a bulk 10 uF tantalum or ceramic on the main supply. The PIC16F874A-E/PT supports 4.0V to 5.5V operation only; for 3.3V designs, choose the PIC16LF874A variant instead.
Keep the ICSP/ICD pins (RB3/PGM, RB6/PGC, RB7/PGD) routed with short, direct traces to an in-system programming header. The 44-pin TQFP requires castellated or via-in-pad PCB layout to expose the ICSP pins under the package. Avoid placing ferrite beads between VDD and the MCU decoupling capacitors, as in-circuit debuggers inject VPP through these lines.
Do not connect the ADC input to a voltage exceeding VDD + 0.3 V or falling below VSS - 0.3 V, even when the channel is disabled - this can trigger latchup. Always configure unused I/O pins as outputs (drive low) to minimize current draw and reduce EMI susceptibility. Brown-out reset (BOR) must be enabled in the configuration word for reliable operation on industrial 24V-derived rails.
Estimated: At 20 MHz CPU clock with the MSSP running SPI at Fosc/4 = 5 MHz, keep SPI traces under 50 mm with 50 ohm characteristic impedance. Place 33 ohm series resistors at the source end of SCK and SDO if the bus length exceeds 25 mm. For I2C operation above 400 kHz, use 4.7 kohm pull-ups and ensure that the bus capacitance stays below 100 pF.
合規資訊
RoHS compliant per Microchip product page. The -E temperature grade covers -40C to +125C but the device is not AEC-Q100 qualified; for AEC-Q100 automotive applications, use PIC18F-K or PIC16F-K variants with automotive qualification.