PIC16F874AT-I/L - 8-bit 20MHz PIC MCU, 7KB Flash, 44-PLCC | Microchip
MPN: PIC16F874AT-I/L ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.86 | $9.86 |
| 10 | $8.97 | $89.70 |
| 100 | $7.92 | $792.00 |
| 500 | $6.94 | $3,470.00 |
| 1,000 | $5.88 | $5,880.00 |
PIC16F874AT-I/L Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, program and data memory, I/O peripherals, and timers on a single silicon die. The 8-bit PIC16 architecture sits in the wider hierarchy: microcontroller -> embedded processor -> semiconductor device. The PIC16F874A family specifically targets mid-range embedded applications that require more I/O and analog integration than the PIC16F873A/876A, while remaining code-compatible with the smaller PIC16C7X legacy family.
Key features include 33 digital I/O pins, a 10-bit Analog-to-Digital Converter with up to 8 input channels, two 8-bit and one 16-bit timers, two analog comparators, a Parallel Slave Port (PSP), and a USART, MSSP (I2C/SPI) communication block. Brown-out Reset (BOR), Power-on Reset (POR), Watchdog Timer (WDT) with on-chip RC oscillator, and In-Circuit Serial Programming (ICSP) provide robust field deployment. The device operates across the industrial -40C to +85C range.
The PIC16F874A core is a Harvard-architecture RISC processor with 35 single-word instructions, a hardware multiplier, and 14-bit wide instruction words. Compared with the earlier PIC16C7X OTP parts, the 16F874A replaces EPROM with Flash, enabling in-application self-programming and ICD debugging without an emulator. The 33 I/O lines and PSP allow direct connection to external parallel buses, making the device attractive for legacy industrial control panels.
Typical applications include industrial automation and PLC I/O modules, automotive body electronics (non-safety), consumer appliance control panels, sensor-conditioning front-ends, and small home-appliance controllers. The wide 2.0V to 5.5V VDD range supports both 3.3V and 5V designs.
When designing with this MCU, allocate one decoupling capacitor (100 nF ceramic) per power pin placed within 5 mm of the IC, and a bulk 10 uF tantalum on the main VDD rail. Note that the device is in the mature PIC16F legacy family; for new high-volume designs consider the pin-compatible PIC16F877A-I/L which doubles program memory to 14 KB and RAM to 368 bytes.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16F874AT-I/L — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC16F874AT-I/L (same form factor and footprint) — differing in Operating Temperature, Core Architecture, Package, Timers, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F874A-I/L
✅ Drop-In✓ In Stock
$5.2 / Unit
View Datasheet →PIC16F874AT-E/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F874A-E/L
✅ Drop-In✓ In Stock
$5.55 / Unit
View Datasheet →PIC16F874-04I/L
✅ Drop-In✓ In Stock
$5.4 / Unit
View Datasheet →PIC16F877A-I/L
✅ Drop-In✓ In Stock
$7.12 / Unit
View Datasheet →PIC16F874AT-I/L Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 8-bit RISC |
| Program Memory Type | Flash |
| Program Memory Size | 7 KB (4K x 14 words) |
| Data RAM | 192 bytes |
| EEPROM Data Memory | 128 bytes |
| Maximum CPU Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Operating Voltage (VDD) | 2.0 V to 5.5 V |
| I/O Pins | 33 |
| ADC | 10-bit, up to 8 channels |
| Timers | Two 8-bit + one 16-bit |
| Analog Comparators | 2 |
| Communication Interfaces | USART, MSSP (I2C/SPI), PSP |
| Brown-out Reset / Power-on Reset | Yes |
| Watchdog Timer | Yes (with on-chip RC oscillator) |
| In-Circuit Serial Programming (ICSP) | Yes |
| Package | 44-PLCC (16.59 x 16.59 mm) |
| Operating Temperature | -40C to +85C (industrial) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free / Halogen-Free | Lead-free (per Microchip product page) |
| Instruction Set | 35 single-word instructions |
| Architecture Type | Harvard |
PIC16F874AT-I/L Pin Configuration
| Pin 1 | MCLR/VPP/RE3 — Master Clear reset / Programming voltage input / PORTE bit 3 |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / Analog input 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI/C1OUT — PORTA bit 4 / Timer 0 clock input / Comparator 1 output |
| Pin 7 | RA5/AN4/SS/C2OUT — PORTA bit 5 / Analog input 4 / SPI slave select / Comparator 2 output |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / Parallel Slave Port read / Analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / Parallel Slave Port write / Analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / Parallel Slave Port chip select / Analog input 7 |
| Pin 11 | VDD — Positive power supply (2.0V to 5.5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator output / clock output (FOSC/4) |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer 1 oscillator output / Timer 1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer 1 oscillator input / Capture-Compare-PWM 2 |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / Capture-Compare-PWM 1 |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 20 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 21 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 22 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 23 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — PORTC bit 6 / USART transmit / USART clock |
| Pin 26 | RC7/RX/DT — PORTC bit 7 / USART receive / USART data |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 28 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 29 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| Pin 30 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| Pin 31 | VSS — Ground reference (second VSS pin) |
| Pin 32 | VDD — Positive power supply (second VDD pin) |
| Pin 33 | RB0/INT — PORTB bit 0 / External interrupt |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3/PGM — PORTB bit 3 / Low-voltage programming |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6/PGC — PORTB bit 6 / In-Circuit Debugger clock / ICSP clock |
| Pin 40 | RB7/PGD — PORTB bit 7 / In-Circuit Debugger data / ICSP data |
| Pin 41 | NC — Not connected (PLCC pin 41 - no internal connection) |
| Pin 42 | NC — Not connected (PLCC pin 42 - no internal connection) |
| Pin 43 | NC — Not connected (PLCC pin 43 - no internal connection) |
| Pin 44 | NC — Not connected (PLCC pin 44 - no internal connection) |
Typical Applications
PIC16F874AT-I/L is suitable for 6 applications: Industrial Automation PLC I/O Module, Consumer Appliance Control Panel, Automotive Body Electronics Module, Sensor Conditioning and Data Acquisition Front-End, Small Home Appliance Controller, HVAC Thermostat and Zone Controller.
Industrial Automation PLC I/O Module
The PIC16F874AT-I/L fits industrial PLC I/O modules because its 33 digital I/O pins, 10-bit ADC with 8 channels, and Parallel Slave Port directly interface to digital sensors, relay banks, and field-bus transceivers. At 20 MHz the MCU provides 5 MIPS, easily handling debouncing, pulse counting, and Modbus RTU over the integrated USART. The 2.0V-5.5V VDD range and industrial -40C to +85C operating window suit 24V-rail PLC chassis with internal regulation. Compared with smaller PIC16F873A parts, the 7 KB Flash and 192-byte RAM allow full IEC 61131-3 ladder logic plus diagnostic state machines. Recommended companions include the MCP2551 CAN transceiver for CANopen and the MAX485 for RS-485 industrial fieldbus.
Recommended
Consumer Appliance Control Panel
The PIC16F874AT-I/L is widely deployed in washing-machine, dishwasher, and microwave control panels because its 33 I/O directly drive LED indicators, 7-segment displays, keypad matrices, and triac-fired heater loads. The 10-bit ADC reads NTC temperature sensors, water-level probes, and motor current shunts with sufficient resolution for closed-loop control. The integrated EEPROM (128 bytes) stores user preferences, fault logs, and calibration constants across power cycles without external memory. Brown-out Reset and Watchdog Timer provide the field reliability required by IEC 60335 household-appliance safety standards. Drop-in upgrade to PIC16F877A-I/L enables firmware expansion for IoT-connected variants.
Recommended
Automotive Body Electronics Module
For non-safety body-electronics applications such as HVAC blend-door control, mirror position memory, and accessory multiplexers, the PIC16F874AT-I/L offers the required I/O count, ADC resolution, and PWM channels. However, for true automotive deployment the AEC-Q100-qualified PIC16F874A-I/PT variant is mandatory because the standard PIC16F874AT-I/L is only specified to -40C to +85C. The 33 I/O drive LIN-bus transceivers, Hall-effect sensors, and brushed DC motor H-bridges. The USART interfaces to a master BCM (Body Control Module) over LIN, while the MSSP block handles SPI sensors. Brown-out Reset prevents ECU latch-up during cranking voltage transients.
Recommended
Sensor Conditioning and Data Acquisition Front-End
The PIC16F874AT-I/L's 10-bit ADC, two analog comparators, and 33 I/O make it an effective sensor-conditioning front-end for multi-channel temperature, pressure, and strain-gauge systems. Its 20 MHz CPU performs moving-average filtering and linearization in firmware, while the USART streams data to a host processor at up to 115.2 kbps. The 192-byte RAM holds sample buffers for 50+ readings before transmission. The internal EEPROM retains calibration constants across power cycles. Compared with a discrete op-amp + ADC solution, the integrated approach reduces BOM cost and PCB area by ~40%.
Recommended
Small Home Appliance Controller
Coffee machines, bread makers, and slow cookers use the PIC16F874AT-I/L as their main controller because the 33 I/O directly interface with keypad scanners, LCD character displays, buzzer drivers, and triac-based heater control. The 10-bit ADC reads thermistor temperature sensors with 1C accuracy using simple firmware linearization. The integrated EEPROM (128 bytes) retains brewing profiles and user presets. The MSSP block drives SPI-based OLED displays on premium variants. The 2.0V-5.5V VDD allows direct 3.3V operation from USB-powered designs.
Recommended
HVAC Thermostat and Zone Controller
The PIC16F874AT-I/L provides the I/O, ADC resolution, and PWM channels required for residential and light-commercial HVAC thermostats. Its 10-bit ADC accurately reads 10 kohm NTC thermistors with 0.5C resolution after firmware linearization. The integrated EEPROM stores setpoint schedules and fault history across power cycles. The USART interfaces to a wireless module for Wi-Fi/BLE connectivity on smart-thermostat variants. Brown-out Reset and Watchdog Timer ensure reliable operation across brown-out events common in HVAC power wiring. For commercial 24VAC thermostats, the 5.5V VDD max is bridged with a small buck regulator.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F874AT-I/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F874A-I/L | PIC16F874AT-E/L | PIC16F874A-E/L | PIC16F874-04I/L | PIC16F877A-I/L |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-PLCC | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same |
| Program Flash | 7 KB | 7 KB | 7 KB | 7 KB | ROM 4 KB (no Flash) | 14 KB (+100%) |
| Data RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 368 bytes (+92%) |
| Maximum CPU Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 4 MHz (-80%) | 20 MHz |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C | -40C to +125C (extended) | -40C to +125C (extended) | -40C to +85C | -40C to +85C |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| ADC | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels |
| AEC-Q100 Qualified | No | No | No | No | No | No |
Key Differentiators
- Tape and Reel production packaging (vs PIC16F874A-I/L)
- Industrial temperature grade at standard price (vs PIC16F874AT-E/L)
- Drop-in upgradability to PIC16F877A-I/L (vs PIC16F877A-I/L)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of every VDD/AVDD pin and a single bulk 10 uF tantalum or aluminum electrolytic on the main VDD rail. For mixed-signal designs using the ADC, add a ferrite bead or 10 ohm resistor between VDD and AVDD, with a dedicated 100 nF + 10 uF decoupling pair on AVDD. The PIC16F874AT-I/L draws ~2 mA active at 5V/20 MHz and ~1 uA in sleep, so power budgeting for battery-backed designs is straightforward.
Keep the 20 MHz crystal (or ceramic resonator) traces to OSC1/OSC2 short (<10 mm) and surrounded by a ground pour. Place MCLR pull-up (typically 10 kohm) close to the pin with a 100 nF cap on the MCLR line for noise immunity. The ICSP connector should be a 6-pin header with standard Microchip pinout (1=MCLR, 2=VDD, 3=VSS, 4=PGD, 5=PGC, 6=NC) for PICKit compatibility.
Estimated: at 20 MHz CPU clock, total power dissipation in a 44-PLCC is approximately 50-70 mW active (per Microchip DC characteristics), so thermal management is rarely an issue. However, two common pitfalls: (1) failing to disable the Watchdog Timer in low-latency interrupt routines causes unexpected resets, and (2) configuring PORTE as PSP without the TRISE register properly set can block analog inputs AN5-AN7. Always set TRISE<PSPMODE> bit correctly before using Parallel Slave Port.
Compliance Information
RoHS compliant per Microchip product page. AEC-Q100 not qualified - use PIC16F874A-I/PT for automotive. Halogen-free status not explicitly listed in provided data.
