PIC16F84AT-20E/SO - 8-bit 20MHz 1.75KB Flash MCU | Microchip
MPN: PIC16F84AT-20E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.65 | $5.65 |
| 10 | $5.09 | $50.90 |
| 100 | $4.52 | $452.00 |
| 500 | $4.07 | $2,035.00 |
| 1,000 | $3.62 | $3,620.00 |
PIC16F84AT-20E/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory, working RAM, and programmable I/O peripherals. The PIC16F84A belongs to the mid-range PIC16 family, which sits between baseline PIC10/12/14 devices and enhanced PIC18 devices in Microchip's portfolio. Within the broader taxonomy, PIC microcontrollers are part of the 8-bit RISC microcontroller category, used widely in industrial, automotive, and consumer embedded applications where deterministic timing, low cost, and ease of programming outweigh the need for high MIPS.
Key features include 13 digital I/O pins arranged on two ports (PORTA 5-bit, PORTB 8-bit), a 10-bit successive approximation ADC channel, four interrupt sources, a 14-bit instruction word, and an internal watchdog timer with on-chip RC oscillator. The device operates from 2.0 V to 5.5 V, includes in-circuit serial programming (ICSP) capability, and supports 1,000,000 typical erase/write cycles on its Flash program memory with greater than 40 years of data retention on EEPROM.
Architecturally, the PIC16F84A uses a separate instruction and data bus (Harvard architecture) which allows instruction fetch and operand read to occur simultaneously. Its 8-bit data path, 14-bit program bus, and small footprint deliver deterministic execution suitable for real-time control, while a hardware multiplier is not present - multiplication is performed in software. Power management includes sleep mode with wake-up via interrupts, suitable for battery-powered and energy-conscious designs.
Typical applications include industrial automation controllers, sensor interface modules, automotive body electronics, low-cost consumer appliances, LED lighting controllers, and remote-control transmitter/receiver platforms. The 18-SOIC package allows easy hand-prototyping and reflow soldering on standard 0.1"-pitch adapters.
When designing with this part, observe the maximum clock-versus-supply-voltage curve: at 5.5 V the device supports the full 20 MHz; below 4.0 V, the maximum frequency must be derated. Always use decoupling capacitors of 0.1 uF and 10 uF near the VDD pin, and reserve the MCLR/VPP pin for in-circuit serial programming access.
This page synthesizes distributor stock, parametric drop-in alternatives, and engineering design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16F84AT-20E/SO — 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 PIC16F84AT-20E/SO (same form factor and footprint) — differing in Package, Core Architecture, I/O Pins, Instruction Execution Time, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F84A-20E/SO
✅ Drop-In✓ In Stock
$2.63 / Unit
View Datasheet →PIC16F84A-20I/SO
✅ Drop-In✓ In Stock
$2.2 / Unit
View Datasheet →PIC16F84A-20/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC16F84A-04E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F84A-04I/SO
✅ Drop-In✓ In Stock
$3.59 / Unit
View Datasheet →PIC16F84AT-20E/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC16 RISC |
| Core Clock Speed | 20 MHz |
| Program Memory Type | Flash |
| Program Memory Size | 1.75 KB (1K x 14) |
| RAM Size | 68 bytes (68 x 8) |
| EEPROM Size | 64 bytes |
| Number of I/O Pins | 13 |
| ADC | 10-bit SAR (4 channels on PIC16F84A) |
| Instruction Word Width | 14-bit |
| Instruction Set Size | 35 single-word instructions |
| Instruction Execution Time | 200 ns at 20 MHz |
| Supply Voltage | 2.0 V to 5.5 V |
| Operating Temperature | -40C to +125C (Extended, "E") |
| Package | 18-SOIC (0.295", 7.50 mm width) |
| Mounting Type | Surface Mount |
| Packaging Form | Tape & Reel ("T" suffix) |
| Watchdog Timer | Yes, internal RC oscillator |
| In-Circuit Programming | Yes (ICSP, MCLR/VPP) |
| Data Retention | >40 years (EEPROM) |
| Erase/Write Cycles | 1,000,000 typical (Flash) |
| RoHS Status | Compliant |
PIC16F84AT-20E/SO Pin Configuration
| Pin 1 | RA2 — PORTA bit 2 (bidirectional digital I/O) |
| Pin 2 | RA3 — PORTA bit 3 (bidirectional digital I/O) |
| Pin 3 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 4 | MCLR/VPP — Master Clear reset (active low) / programming voltage input |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — PORTB bit 0 / external interrupt input |
| Pin 7 | RB1 — PORTB bit 1 |
| Pin 8 | RB2 — PORTB bit 2 |
| Pin 9 | RB3/PGM — PORTB bit 3 / ICSP LVP enable |
| Pin 10 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 11 | RB5 — PORTB bit 5 (interrupt-on-change) |
| Pin 12 | RB6/PGC — PORTB bit 6 / ICSP clock input |
| Pin 13 | RB7/PGD — PORTB bit 7 / ICSP data I/O |
| Pin 14 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock output (FOSC/4) |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 17 | RA0 — PORTA bit 0 |
| Pin 18 | RA1 — PORTA bit 1 |
Typical Applications
PIC16F84AT-20E/SO is suitable for 7 applications: Industrial Sensor Interface Module, Automotive Body Electronics Controller, Consumer Remote Control Transmitter/Receiver, LED Lighting Dimmer Controller, Battery-Powered IoT Sensor Node, Educational Trainer and Hobby Projects, Home Appliance Control Board.
Industrial Sensor Interface Module
The PIC16F84AT-20E/SO fits industrial sensor interface modules because its 13 digital I/O pins can directly drive switches, opto-isolated inputs, and 4-20 mA loop interfaces while the 10-bit ADC channel digitizes analog transducer signals. Its 20 MHz instruction rate yields a 200 ns cycle time, which is adequate for closed-loop control of pressure, flow, and temperature sensors. The extended -40C to +125C temperature rating handles factory-floor thermal stress, and the 18-SOIC package reflows cleanly onto industrial PCBs. Engineers typically pair it with an MCP2551 CAN transceiver or MAX485 RS-485 transceiver for networked sensor hubs.
Recommended
Automotive Body Electronics Controller
The PIC16F84AT-20E/SO serves automotive body electronics such as interior lighting controllers, mirror adjusters, and door-lock drivers. Its 13 I/O pins drive relays and LED strings directly, and the 20 MHz core supports PWM generation for dimming and motor speed control. The -40C to +125C extended temperature grade meets automotive under-hood and cabin thermal environments. The 1.75 KB Flash comfortably holds calibration tables and fault-handling routines. Designers commonly use it with TIP120 Darlington drivers and BTS432 automotive high-side switches for actuator control.
Recommended
Consumer Remote Control Transmitter/Receiver
The PIC16F84AT-20E/SO fits low-cost RF remote control transmitters because its 35-instruction RISC core is small enough to fit in 1.75 KB Flash while still leaving room for encrypted rolling-code algorithms. Its sleep-mode current under 1 uA typical extends coin-cell battery life to years. The ICSP programming pinout allows firmware updates during manufacturing. Pair it with an ASK/OOK transmitter such as the MICRF112 for sub-1 GHz remote-control applications, or with an IR LED for line-of-sight universal remotes.
Recommended
LED Lighting Dimmer Controller
The PIC16F84AT-20E/SO controls LED dimmers by generating high-resolution PWM at 20 MHz with its hardware CCP module, producing smooth 8-bit or 10-bit duty-cycle modulation for color mixing and brightness control. The 13 I/O pins drive multiple LED channels and accept tactile-switch input for user controls. Its 2.0 V to 5.5 V supply range allows operation directly from a single Li-ion cell or USB rail. Typical designs combine it with constant-current LED drivers like the TLC5940 or WS2811 addressable LED chains.
Recommended
Battery-Powered IoT Sensor Node
The PIC16F84AT-20E/SO suits battery-powered IoT sensor nodes because its sleep mode draws < 1 uA typical, allowing months of operation on AA cells when duty-cycled. Its 10-bit ADC reads temperature, light, or gas-sensor analog outputs, while 13 I/O pins interface SPI or I2C peripherals. The 2.0 V minimum supply allows operation down to near-end-of-life battery voltage. Pair it with an ESP8266 or nRF24L01+ radio for sub-GHz wireless uplink, and with an MCP1700 low-dropout regulator for clean sensor power.
Recommended
Educational Trainer and Hobby Projects
The PIC16F84AT-20E/SO is widely used in educational microcontroller trainers and hobby projects because the 18-SOIC package fits on 0.1"-pitch adapters and breadboards (when used with an SOIC-to-DIP carrier). The 35-instruction RISC instruction set is approachable for first-time learners, and the ICSP programming interface works with inexpensive PICkit 3 or PICkit 4 programmers. Typical classroom projects include stopwatch timers, traffic-light controllers, and basic frequency counters. Reference material and example code are abundant in Microchip application notes and university course curricula.
Recommended
Home Appliance Control Board
The PIC16F84AT-20E/SO integrates home-appliance control boards such as washing-machine timers, microwave oven user interfaces, and air-conditioner remote receivers. Its 13 I/O pins scan keypads and drive 7-segment or LCD character displays, while the 64-byte EEPROM stores user-set preferences across power cycles. The extended -40C to +125C temperature rating handles the thermal envelope of kitchen and laundry environments. Designs typically include triac drivers such as the MOC3021 for AC load switching.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F84AT-20E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F84A-20E/SO | PIC16F84A-20I/SO | PIC16F84A-20/SO | PIC16F84A-04E/SO | PIC16F84A-04I/SO |
|---|---|---|---|---|---|---|
| Package | 18-SOIC (7.50 mm) | 18-SOIC (7.50 mm) - same | 18-SOIC (7.50 mm) - same | 18-SOIC (7.50 mm) - same | 18-SOIC (7.50 mm) - same | 18-SOIC (7.50 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 4 MHz | 4 MHz |
| Program Memory | 1.75 KB (1K x 14) Flash | 1.75 KB Flash | 1.75 KB Flash | 1.75 KB Flash | 1.75 KB Flash | 1.75 KB Flash |
| RAM | 68 bytes | 68 bytes | 68 bytes | 68 bytes | 68 bytes | 68 bytes |
| Number of I/O | 13 | 13 | 13 | 13 | 13 | 13 |
| Operating Temperature | -40C to +125C (E) | -40C to +125C (E) | -40C to +85C (I) | -40C to +85C | -40C to +125C (E) | -40C to +85C (I) |
| Packaging Form | Tape & Reel (T) | Tube | Tube | Tube | Tube | Tube |
Key Differentiators
- Extended temperature grade with tape-and-reel packaging (vs PIC16F84A-20I/SO)
- 20 MHz full-speed performance versus 4 MHz economy grade (vs PIC16F84A-04E/SO)
- Identical firmware compatibility across the PIC16F84A 18-SOIC family (vs PIC16F83-04/SO (related family))
Design Notes
Decouple the VDD pin (pin 14) with both a 100 nF (0.1 uF) ceramic and a 10uF electrolytic/ceramic capacitor placed within 5 mm of the pin. The 0.1 uF cap absorbs high-frequency switching noise from digital I/O transitions while the bulk cap holds up VDD during peak current surges from PORTB drive. Estimate: a single PORTB pin can sink up to 25 mA; simultaneous switching of multiple pins can demand > 100 mA peak transients.
Route the MCLR/VPP pin (pin 4) directly to a programming header with a 10 kohm pull-up to VDD and no series capacitor (unless in-circuit programming is disabled). The ICSP clock (PGC, pin 12) and data (PGD, pin 13) traces should be kept short (< 50 mm) and shielded from adjacent switching signals to prevent programming failures. Place the crystal/oscillator traces on the same side as the IC, with a ground guard ring for EMI-sensitive designs.
Common pitfalls when designing with PIC16F84AT-20E/SO include: (1) exceeding the maximum clock-versus-voltage curve - at VDD below 4.0 V the 20 MHz rating does not apply, you must use the 4 MHz version; (2) driving the MCLR pin without proper pull-up - floating MCLR can cause spurious resets; (3) forgetting to disable the watchdog timer in software if not used, which causes unintended resets every ~18 ms; (4) sourcing too much current from PORTB - the entire PORTB can only source 100 mA total, exceeding this triggers latch-up.
Estimated: the 18-SOIC package has a theta_JA of approximately 70 C/W on a standard 4-layer JEDEC test board (per Microchip thermal data for similar SOIC packages). At maximum supply (5.5 V) and maximum clock (20 MHz), the active current draw is approximately 10 mA, dissipating 55 mW - well within safe thermal limits. Sleep mode current is < 1 uA typical, yielding < 5.5 uW dissipation - negligible thermal stress.
Compliance Information
RoHS and REACH compliance per Microchip product page. Not AEC-Q100 qualified - this part is industrial/consumer grade, not automotive grade despite the extended temperature range. For AEC-Q100 qualified automotive PICs, consider PIC16F84A-E/SO automotive variants or PIC16F193x series.