PIC16F874AT-E/PT - 20MHz 8-Bit MCU 7KB FLASH 44-TQFP | Microchip
MPN: PIC16F874AT-E/PT β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.65 | $8.65 |
| 10 | $7.95 | $79.50 |
| 100 | $7.2 | $720.00 |
| 500 | $6.45 | $3,225.00 |
| 1,000 | $5.7 | $5,700.00 |
PIC16F874AT-E/PT Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, RAM, peripherals, and I/O into one package. PIC microcontrollers use a Harvard RISC architecture with 35 single-word instructions, which gives them deterministic instruction timing and very low power consumption per MIPS. The PIC16F874A family sits between the smaller PIC16F87x (28-pin) and the larger PIC16F877A (40/44-pin with more I/O) - it offers the same peripheral set as the '877A but with reduced pin count, making it the right choice when 33 I/O are sufficient and 40-pin parts are over-budget.
Key features include 33 digital I/O lines, 5 channels of 10-bit ADC (up to 8 channels on the '877A), 2 analog comparators, a USART, an MSSP (SPI / I2C master-slave), 2 capture/compare/PWM modules, 2 8-bit timers plus 1 16-bit timer, an ICD (In-Circuit Debug) port, and self-programming. The enhanced PIC16F874A core adds a hardware multiplier and 14-bit instruction word, doubling arithmetic density over the original PIC16C7X. A 200 ns instruction execution time at 20 MHz provides real-time interrupt latency suitable for motor, power-conversion, and sensor feedback loops.
Typical applications include industrial control boards, automotive body and chassis ECUs, consumer white goods (washing machines, dishwashers, microwave ovens), HVAC thermostats, sensor-conditioning front ends, and any legacy embedded design that must remain sourceable for the next 5-10 years thanks to Microchip's Enhanced Flash program memory. The wide 2.0 V to 5.5 V operating range allows direct battery or 5 V regulator supplies.
For design in, populate the ICSP/ICD pins (RB6/RB7, MCLR) on every board even if you do not plan to debug in-circuit - you can recover bricked parts in production. The 44-TQFP uses Microchip's standard pinout shared with PIC16F877A-I/PT and PIC18F452-I/PT, enabling a single PCB layout to accept multiple MCU families.
This page synthesizes distributor stock, NRND lifecycle status, drop-in alternatives, and practical design notes not found on the manufacturer datasheet, distilled for the working engineer.
Drop-in alternatives for PIC16F874AT-E/PT β 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-E/PT (same form factor and footprint) β differing in Package, Timers, Core Architecture, Operating Temperature, Serial Interfaces.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16F874A-E/PT
β Drop-Inβ In Stock
$7.45 / Unit
View Datasheet βPIC16F874A-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16F877A-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16F874-10E/PT
β Drop-Inβ In Stock
$6.55 / Unit
View Datasheet βPIC18F452-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC18F4520-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16F874AT-E/PT Maximum Ratings & Electrical Characteristics
| Product Family | PIC16F874A |
| Core Architecture | 8-bit PIC RISC (14-bit instruction word) |
| Instruction Set | 35 single-word instructions |
| Instruction Execution Time | 200 ns at 20 MHz |
| Maximum Clock Frequency | 20 MHz |
| Program Memory (Flash) | 7 KB (4K x 14) |
| RAM | 192 bytes |
| EEPROM Data Memory | 128 bytes |
| I/O Pins | 33 |
| ADC | 10-bit, up to 8 channels |
| Comparators | 2 |
| Timers | 2 x 8-bit, 1 x 16-bit |
| Capture/Compare/PWM (CCP) | 2 modules |
| Serial Interfaces | USART + MSSP (SPI / I2C) |
| In-Circuit Debug (ICD) | Yes (2-wire on RB6/RB7) |
| Self-Programming | Yes |
| Supply Voltage | 2.0 V to 5.5 V |
| Operating Temperature | -40 C to +125 C (E - Extended grade) |
| Package | 44-TQFP (PT), 10x10 mm |
| Packaging | Tape & Reel (T suffix) |
| RoHS Status | Compliant |
PIC16F874AT-E/PT Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 β PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 β PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2/VREF- β PORTA bit 2 / analog input 2 / ADC Vref- |
| Pin 5 | RA3/AN3/VREF+ β PORTA bit 3 / analog input 3 / ADC Vref+ |
| Pin 6 | RA4/T0CKI β PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS β PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 β PORTE bit 0 / read control for parallel slave port / analog input 5 |
| Pin 9 | RE1/WR/AN6 β PORTE bit 1 / write control / analog input 6 |
| Pin 10 | RE2/CS/AN7 β PORTE bit 2 / chip select / analog input 7 |
| Pin 11 | VDD β Positive supply voltage (+2.0 to +5.5 V) |
| Pin 12 | VSS β Ground reference |
| Pin 13 | OSC1/CLKI β Crystal oscillator input / external clock in |
| Pin 14 | OSC2/CLKO β Crystal oscillator output / clock out |
| Pin 15 | RC0/T1OSO/T1CKI β PORTC bit 0 / Timer1 oscillator out / Timer1 clock in |
| Pin 16 | RC1/T1OSI/CCP2 β PORTC bit 1 / Timer1 oscillator in / CCP2 I/O |
| Pin 17 | RC2/CCP1 β PORTC bit 2 / CCP1 I/O |
| Pin 18 | RC3/SCK/SCL β PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 β PORTD bit 0 / parallel slave port bit 0 |
| Pin 20 | RD1/PSP1 β PORTD bit 1 / parallel slave port bit 1 |
| Pin 21 | RD2/PSP2 β PORTD bit 2 / parallel slave port bit 2 |
| Pin 22 | RD3/PSP3 β PORTD bit 3 / parallel slave port bit 3 |
| Pin 23 | RC4/SDI/SDA β PORTC bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO β PORTC bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK β PORTC bit 6 / USART TX / USART clock |
| Pin 26 | RC7/RX/DT β PORTC bit 7 / USART RX / USART data |
| Pin 27 | RD4/PSP4 β PORTD bit 4 / parallel slave port bit 4 |
| Pin 28 | RD5/PSP5 β PORTD bit 5 / parallel slave port bit 5 |
| Pin 29 | RD6/PSP6 β PORTD bit 6 / parallel slave port bit 6 |
| Pin 30 | RD7/PSP7 β PORTD bit 7 / parallel slave port bit 7 |
| Pin 31 | VSS β Ground reference |
| Pin 32 | VDD β Positive supply voltage (+2.0 to +5.5 V) |
| Pin 33 | RB0/INT β PORTB bit 0 / external interrupt |
| Pin 34 | RB1 β PORTB bit 1 |
| Pin 35 | RB2 β PORTB bit 2 |
| Pin 36 | RB3/PGM β PORTB bit 3 / low-voltage programming |
| Pin 37 | RB4 β PORTB bit 4 |
| Pin 38 | RB5 β PORTB bit 5 |
| Pin 39 | RB6/PGC β PORTB bit 6 / ICSP clock (debug) |
| Pin 40 | RB7/PGD β PORTB bit 7 / ICSP data (debug) |
| Pin 41 | NC β Not connected (per datasheet) |
| Pin 42 | NC β Not connected (per datasheet) |
| Pin 43 | NC β Not connected (per datasheet) |
| Pin 44 | NC β Not connected (per datasheet) |
Typical Applications
PIC16F874AT-E/PT is suitable for 7 applications: Industrial Control PLCs and Sensor Conditioning, Automotive Body and Chassis ECUs, Consumer White Goods Control Boards, HVAC Thermostats and Building Automation, Battery-Powered Sensor Nodes (with sleep mode), Educational and Hobbyist Microcontroller Projects, Legacy Embedded Systems Maintenance.
Industrial Control PLCs and Sensor Conditioning
The PIC16F874AT-E/PT's 20 MHz core, 10-bit ADC and 33 I/O make it a strong fit for industrial sensor-conditioning front ends and small PLCs. The 192-byte RAM supports modest PID control loops while the 7 KB Flash holds state-machine logic for multi-channel analog inputs. Operates directly from 24 V industrial rails stepped down to 5 V. The -40 C to +125 C industrial range tolerates cabinet temperatures. Place the ICSP header on every board for field firmware updates.
Recommended
Automotive Body and Chassis ECUs
The PIC16F874AT-E/PT's Extended -40 C to +125 C temperature grade and 33 I/O fit body-electronics modules like seat controllers, mirror adjusters, lighting drivers and HVAC blend-door actuators. The 2 CCP modules generate PWM for servo positioning while the MSSP drives I2C sensor clusters. Note this part is industrial-grade not AEC-Q100 - for safety-critical ECUs migrate to PIC16F1938-I/PT or dsPIC33. The 5 V tolerance on every I/O simplifies integration with 12 V automotive transients.
Recommended
Consumer White Goods Control Boards
Washing machines, dishwashers, microwave ovens, and refrigerators use the PIC16F874AT-E/PT for the user-interface and motor-control board. The 7 KB Flash accommodates multi-button UI state machines plus UART command parsing. The USART interfaces with the main digital board while the PWM outputs drive motor triac gates. The Harvard architecture provides deterministic interrupt latency for safety-critical door-lock and water-level interlocks.
Recommended
HVAC Thermostats and Building Automation
Wall-mounted HVAC thermostats use the PIC16F874AT-E/PT to read multiple thermistor inputs via the 10-bit ADC, drive the LCD, and switch 24 VAC relays through opto-isolated outputs. The 7 KB Flash stores the weekly scheduling algorithm, while 128 bytes of EEPROM retains user settings across power cycles. The Extended temperature grade handles attic-mounted equipment housings that swing from -10 C in winter to 70 C in summer.
Recommended
Battery-Powered Sensor Nodes (with sleep mode)
Although the PIC16F874A is not the lowest-power PIC, its SLEEP mode at <1 uA combined with the MSSP and ADC makes it viable for solar-powered wireless sensor nodes that wake every 30 seconds to read a sensor and transmit. The 7 KB Flash holds a simple protocol stack, while 128-byte EEPROM logs calibration constants. The 2.0 V minimum VDD allows operation directly from two AA cells down to 2.2 V.
Recommended
Educational and Hobbyist Microcontroller Projects
The PIC16F874AT-E/PT is widely used in university embedded-systems courses and Arduino-competitor projects because the 44-TQFP gives more I/O than the 28-pin PIC16F876A while remaining breadboard-friendly with an adapter. MPLAB X IDE, XC8 compiler, and PICkit 3/4 programmer support this part out of the box. The PIC16 instruction set is simple enough for students to learn assembly while the C compiler keeps advanced projects productive.
Recommended
Legacy Embedded Systems Maintenance
Many industrial products designed in the early 2000s used the original PIC16F874 (non-A). The PIC16F874AT-E/PT is the modern Extended-temperature Tape-and-Reel replacement that allows sustaining production of those legacy systems without PCB redesign. The 44-TQFP footprint and instruction set are forward-compatible, and MPLAB development tools continue to support this part. Contact Microchip factory for long-term supply contracts if you need 10-year support.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F874AT-E/PT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F874A-E/PT | PIC16F874A-I/PT | PIC16F877A-I/PT | PIC16F874-10E/PT | PIC18F452-I/PT | PIC18F4520-I/PT |
|---|---|---|---|---|---|---|---|
| Package | 44-TQFP (PT) 10x10 mm | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Flash | 7 KB (4K x 14) | 7 KB - same | 7 KB - same | 14 KB (+100%) | 4 KB (-43%) | 16 KB (+129%) | 32 KB (+357%) |
| RAM | 192 bytes | 192 bytes - same | 192 bytes - same | 192 bytes - same | 192 bytes - same | 1536 bytes (+700%) | 1536 bytes (+700%) |
| EEPROM | 128 bytes | 128 bytes - same | 128 bytes - same | 256 bytes (+100%) | 64 bytes (-50%) | 256 bytes (+100%) | 256 bytes (+100%) |
| I/O Pins | 33 | 33 - same | 33 - same | 40 (+21%) | 33 - same | 33 - same | 36 (+9%) |
| ADC Channels | 8 channels, 10-bit | 8 ch, 10-bit - same | 8 ch, 10-bit - same | 8 ch, 10-bit - same | 8 ch, 10-bit - same | 8 ch, 10-bit - same | 13 ch, 10-bit (+62%) |
| Max Clock Frequency | 20 MHz | 20 MHz - same | 20 MHz - same | 20 MHz - same | 10 MHz (-50%) | 40 MHz (+100%) | 40 MHz (+100%) |
| Operating Temperature | -40 C to +125 C (E grade) | -40 C to +125 C - same | 0 C to +70 C (I grade) | 0 C to +70 C (I grade) | -40 C to +125 C - same | 0 C to +70 C (I grade) | 0 C to +70 C (I grade) |
| Core Architecture | PIC16 (14-bit instruction) | PIC16 (14-bit) - same | PIC16 (14-bit) - same | PIC16 (14-bit) - same | PIC16 (14-bit) - same | PIC18 (16-bit) - firmware rewrite required | PIC18 (16-bit) - firmware rewrite required |
Key Differentiators
- Industrial Extended temperature in T&R packaging (vs PIC16F874A-I/PT)
- Enhanced 14-bit core with hardware multiplier (vs PIC16F874-10E/PT)
- Right-sized peripheral set with 33 I/O (vs PIC16F877A-I/PT)
- Harvard RISC determinism for hard real-time (vs PIC18F4520-I/PT)
Design Notes
The PIC16F874AT-E/PT requires a single 2.0 V to 5.5 V supply on pins 11 and 32, both of which must be bypassed with 100 nF ceramic capacitors placed within 5 mm of each VDD pin. Estimated: at 20 MHz and 5 V the active current is ~13 mA, while sleep mode drops below 1 uA. For battery applications add a 10 uF bulk capacitor on VDD and consider MCP1700 250 mA LDO for 6-12 V industrial supplies.
Always place a 5-pin ICSP header (MCLR, VDD, VSS, RB6/PGC, RB7/PGD) on every board, even for one-time-only production - this allows recovery of bricked parts and in-circuit firmware updates. The 44-TQFP has 0.8 mm pitch; use NSMD pads with 0.4 mm aperture solder paste for reliable reflow. Estimated: keep-out zone under the QFP body should be filled with thermal vias to a ground plane on layer 2.
The PIC16F874A is a 5 V tolerant MCU - do not connect 3.3 V peripherals directly to PORTB without a level shifter if the PIC runs at 5 V VDD (VIH min is 0.25*VDD+0.8V = 2.05 V so 3.3 V is recognized as HIGH, but VOL of 3.3 V device may exceed PIC VIL). MCLR must have a 10 kohm pull-up to VDD or the part will randomly reset. Configuration bits must be programmed to enable the watchdog, brown-out reset, and low-voltage programming for production firmware.
Keep the 20 MHz crystal traces short (<10 mm) and surround them with a ground pour on the same layer. Estimated: at 20 MHz the second harmonic falls at 40 MHz which can radiate from long OSC traces and couple into analog inputs. Place the ADC reference decoupling capacitor (100 nF) directly on the VREF+ pin (RA3) when using external voltage reference; otherwise tie VREF+ to VDD and accept the reduced ADC absolute accuracy.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - this is industrial-grade (-40 C to +125 C), not automotive-grade. For AEC-Q100 safety-critical automotive ECUs use dsPIC33 or PIC16F1938 with PPAP documentation.
