PIC16F874AT-I/ML - 8-Bit 20MHz 7KB Flash MCU 44-QFN | Microchip
MPN: PIC16F874AT-I/ML ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.45 | $7.45 |
| 10 | $6.71 | $67.10 |
| 100 | $5.96 | $596.00 |
| 500 | $5.36 | $2,680.00 |
| 1,000 | $4.77 | $4,770.00 |
PIC16F874AT-I/ML Overview
What is a PIC16F microcontroller? The PIC16F family is Microchip's mid-range 8-bit RISC microcontroller line based on the Harvard architecture with separate program and data buses, a small instruction set (approximately 35 instructions), and integrated Flash program memory. In the system hierarchy, it sits between the smaller PIC10/PIC12 baseline series and the higher-pin-count PIC18 series. PIC16F874A parts include a 10-bit ADC, USART, MSSP (SPI/I2C), and parallel port peripherals - features that established the family as a workhorse for industrial control in the early 2000s.
Key features include 14 interrupt sources, a 10-bit 8-channel Analog-to-Digital Converter, two 8-bit timers plus one 16-bit timer, and a USART with RS-485 support. The 44-QFN package provides compact footprint with exposed thermal pad, suitable for space-constrained designs. The /ML suffix designates the QFN package and -I suffix designates industrial temperature grade.
The PIC16F874AT-I/ML uses a 14-bit instruction word and modified Harvard architecture with separate code and data paths, enabling single-cycle instruction execution except for program branches. The integrated 10-bit ADC uses successive approximation and supports 8 input channels multiplexed from the 33 I/O pins. The MSSP peripheral implements both SPI and I2C master/slave modes, while the enhanced USART supports RS-232, RS-485, and LIN protocols.
Typical applications include industrial control systems, HVAC controls, motor control interfaces, sensor signal conditioning, smart sensor nodes, and embedded instrumentation. The wide peripheral mix and 33 GPIO make it well-suited to bridge between analog sensors and human-machine interfaces in industrial equipment.
When designing with the PIC16F874AT-I/ML, ensure the supply voltage is decoupled with at minimum 0.1uF ceramic capacitors adjacent to each VDD pin and a bulk 10uF electrolytic on the board. The QFN package requires careful PCB thermal pad soldering - a star-ground pattern from the exposed pad improves thermal dissipation and reduces ground bounce on the analog inputs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, providing information gain beyond what is available on typical distributor listing pages.
Drop-in alternatives for PIC16F874AT-I/ML — 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/ML (same form factor and footprint) — differing in Package, ADC, I/O Pins, Program Memory (Flash), Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F874A-I/ML
✅ Drop-In✓ In Stock
$3.21 / Unit
View Datasheet →PIC16F874AT-E/PT
✅ Drop-In✓ In Stock
$5.7 / Unit
View Datasheet →PIC16F874A-E/PT
✅ Drop-In✓ In Stock
$7.45 / Unit
View Datasheet →PIC16F777-I/ML
✅ Drop-In✓ In Stock
$5.48 / Unit
View Datasheet →PIC16F767-I/ML
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC16F874-04I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F874AT-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit RISC (PIC16 mid-range, 14-bit instruction word) |
| Family | PIC16F874A |
| Program Memory (Flash) | 7 KB |
| RAM | 192 bytes |
| EEPROM | 256 bytes |
| Maximum CPU Frequency | 20 MHz |
| Throughput | 5 MIPS |
| Supply Voltage (VDD) | 4.0 V to 5.5 V |
| I/O Pins | 33 |
| ADC | 10-bit, 8 channels |
| Timers | 2x 8-bit + 1x 16-bit |
| Communication Peripherals | 1x USART (RS-485), 1x MSSP (SPI/I2C) |
| Package | 44-pin QFN (ML), 8x8 mm, with exposed thermal pad |
| Operating Temperature | -40C to +85C (industrial) |
| Temperature Grade | Industrial |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| Lead-Free / RoHS | Yes (compliant per Microchip product page) |
PIC16F874AT-I/ML Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (Reset) input / Programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input channel 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input channel 4 / SPI Slave Select |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / Parallel-port read / Analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / Parallel-port write / Analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / Parallel-port chip select / Analog input 7 |
| Pin 11 | VDD — Positive supply voltage (4.0V-5.5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKI — Oscillator input / External clock input |
| Pin 14 | OSC2/CLKO — Oscillator output / Clock output |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM output |
| 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 |
| Pin 32 | VDD — Positive supply voltage (4.0V-5.5V) |
| Pin 33 | RB0/INT — PORTB bit 0 / External interrupt input |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3/PGM — PORTB bit 3 / Low-voltage ICSP programming input |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock input |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data input/output |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16F874AT-I/ML is suitable for 6 applications: Industrial Control Systems, HVAC Climate Controllers, Sensor Signal Conditioning Hubs, Motor Control Interfaces, Embedded Instrumentation Front-Ends, Smart Sensor Nodes (RS-485 Networks).
Industrial Control Systems
The PIC16F874AT-I/ML fits industrial control boards with its 33 GPIO, 8-channel 10-bit ADC, and RS-485 capable USART. Industrial PLCs, machine controllers, and process instrument boards commonly use this part for its mix of analog inputs, digital I/O, and serial comms in a compact 44-QFN. At 20MHz the 5 MIPS throughput handles PID loops and sensor scanning at typical 1kHz rates. Industrial grade -40C to +85C rating covers factory floor environments without derating. The 7KB Flash supports modest control firmware including Modbus RTU protocol stacks.
Recommended
HVAC Climate Controllers
HVAC wall thermostats and rooftop unit controllers benefit from the PIC16F874AT-I/ML's 8-channel ADC for multiple temperature sensors (NTC thermistor bridges), GPIO for relay/triac control, and USART for BACnet/Modbus comms to building automation systems. The PIC16F874A family has been a long-running HVAC industry workhorse, with reference designs and code libraries widely available from Microchip. The 44-QFN package supports slim-line thermostat form factors. Industrial temperature grade handles unconditioned equipment room environments.
Recommended
Sensor Signal Conditioning Hubs
Multi-sensor data acquisition boards use the PIC16F874AT-I/ML as a conditioning hub: 10-bit ADC digitizes up to 8 analog sensors (temperature, pressure, flow, gas), MSSP I2C bus reads additional digital sensors (accelerometers, humidity), and USART streams processed data upstream. The PIC16F874A's small 192-byte RAM is sufficient for buffering and averaging before transmission. Low-power sleep modes between conversions support battery-powered remote sensor nodes.
Recommended
Motor Control Interfaces
Low-end BLDC and stepper motor control boards use the PIC16F874AT-I/ML for the user interface and supervisory functions: ADC reads motor current shunt amplifier, GPIO drives direction/relay signals, USART receives commands from main controller. While PIC16F874A lacks dedicated motor-control PWM peripherals (which is why PIC18F4439-I/ML is recommended for new designs), it can drive steppers at moderate speeds via timer-interrupt bit-banging. Industrial -40C to +85C rating suits motor drive enclosures.
Recommended
Embedded Instrumentation Front-Ends
Bench-top instruments and panel meters use the PIC16F874AT-I/ML for front-panel control: ADC digitizes measurement inputs (via external op-amp signal conditioning), GPIO drives LCD segments or LED bargraphs, MSSP SPI bus drives TFT displays, USART outputs data to PC. The 44-QFN compact footprint leaves PCB area for analog signal chains. Industrial temperature rating covers laboratory and field-deployed instruments. 5 MIPS throughput is sufficient for filtering and RMS calculations.
Recommended
Smart Sensor Nodes (RS-485 Networks)
Distributed sensor nodes on factory RS-485 networks use the PIC16F874AT-I/ML to digitize local analog channels, run Modbus RTU slave protocol, and communicate over a half-duplex RS-485 bus. The integrated USART with RS-485 support eliminates an external transceiver in many cases (only an external RS-485 line driver like MAX485 is needed). 33 GPIO accommodate multiple discrete sensors per node. Industrial temperature rating supports outdoor or unconditioned installation.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F874AT-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F874A-I/ML | PIC16F874AT-E/PT | PIC16F874A-E/PT | PIC16F777-I/ML | PIC16F767-I/ML | PIC16F874-04I |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-QFN (ML) 8x8 mm | 44-QFN (ML) 8x8 mm - same | 44-QFN (ML) 8x8 mm - same | 44-QFN (ML) 8x8 mm - same | 44-QFN (ML) 8x8 mm - same | 44-QFN (ML) 8x8 mm - same | 44-QFN (ML) 8x8 mm - same |
| Program Memory (Flash) | 7 KB | 7 KB | 7 KB | 7 KB | 14 KB | 14 KB | 7 KB |
| Maximum CPU Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 4 MHz |
| ADC | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 14 channels | 10-bit, 14 channels | 10-bit, 8 channels |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +125C (extended) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| Shipping Media | Tape & Reel | Tube | Tape & Reel | Tube | Tube | Tube | Tube |
| Lifecycle Status | NRND | NRND | NRND | NRND | Active | Active | NRND |
Key Differentiators
- Direct same-die drop-in via PIC16F874A-I/ML (vs PIC16F874A-I/ML)
- Industrial temperature grade (-I) option (vs PIC16F874AT-E/PT)
- PIC16F777-I/ML upgrade path with 2x Flash (vs PIC16F777-I/ML)
Design Notes
The 44-QFN exposed thermal pad (EP) MUST be soldered to a PCB land pattern connected to the ground plane for both mechanical reliability and thermal dissipation. Use a 0.5 mm pitch QFN footprint with multiple thermal vias in the EP land per IPC-7351. A star-ground connection at the EP improves ADC noise performance by reducing digital return-current coupling into analog ground.
Decouple both VDD/VSS pairs (pins 11/12 and 31/32) with 100 nF ceramic capacitors placed within 3 mm of each pin. Add a bulk 10 uF tantalum or aluminum polymer capacitor on the board near the MCU for transient load support. For ADC accuracy use a separate filtered AVdd derived from the same VDD via a ferrite bead to reduce digital switching noise on analog references.
Configuration word (CONFIG) fuses must be programmed correctly: oscillator selection (HS for >4 MHz crystal), watchdog enable/disable, brown-out reset voltage, and code protection. Unprogrammed CONFIG defaults to internal RC oscillator which may cause unexpected timing. Use MPLAB X IDE with the PICkit 3 or PICkit 4 debugger for safe configuration. Avoid enabling low-voltage programming (LVP) if RB3/RB4 are used as I/O - LVP permanently ties RB3 to the ICSP function.
The 10-bit ADC achieves data-sheet accuracy only when the source impedance is below 2.5 kohm. For higher-impedance sensors (e.g., 10 kohm NTC thermistor dividers) add a unity-gain op-amp buffer or use MCP3421 external ADC. The ADC reference voltage (VREF+/VREF-) should be bypassed with 0.1 uF ceramic plus 10 uF electrolytic capacitors for stable conversions below 1 LSB.
Compliance Information
RoHS and REACH compliant per Microchip product page. AEC-Q100 not qualified - extended temperature PIC16F874AT-E/PT variant recommended for automotive. Halogen-free per Microchip environmental compliance datasheet.
