PIC16LF84AT-04/SO - 4MHz 8-bit Flash MCU, 18-SOIC | Microchip
MPN: PIC16LF84AT-04/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.55 | $2,550.00 |
PIC16LF84AT-04/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory (Flash/ROM), data memory (RAM), non-volatile storage (EEPROM), and peripherals such as timers, interrupts, and I/O ports into one IC. PIC microcontrollers use a RISC (Reduced Instruction Set Computer) architecture with a small, fixed-length instruction set (typically 35 instructions), which simplifies decoding and enables deterministic timing — important for embedded control. The PIC16F84A specifically belongs to the PIC16 mid-range family and was one of the most widely adopted Flash microcontrollers of its generation, favored for its simplicity, low cost, and built-in EEPROM.
Key features of the PIC16LF84AT-04/SO include 13 digital I/O pins, an instruction cycle time of 200ns at 4MHz (4 MHz oscillator / 4), 64 bytes of on-chip data EEPROM, 1.75KB Flash program memory, a 14-bit instruction word, and Microchip's nanoWatt technology for low-power operation. The 18-SOIC wide-body package supports standard surface-mount assembly and is compatible with hand-soldering as well as reflow processes.
From a technical depth perspective, the device includes a watchdog timer (WDT) for runaway code recovery, Power-On Reset (POR) for deterministic cold-start behavior, brown-out detection, an 8-bit timer/counter (Timer0), and a high-endurance Flash/EEPROM program memory rated for thousands of write cycles. The 'LF' suffix indicates a low-voltage variant operating from 2.0V to 5.5V, while the 'T' suffix denotes tape-and-reel packaging, and '04' indicates the 4MHz speed grade.
Typical applications include hobbyist electronics and education platforms, simple sensor interfaces, low-cost consumer appliances, replacement of legacy discrete logic, and embedded control nodes. Its combination of Flash, RAM, and EEPROM on a single chip makes it a classic solution for designs that need a small amount of non-volatile data storage alongside program execution.
When designing with the PIC16LF84AT-04/SO, ensure your programmer/debugger is compatible (such as the PICkit 3 or MPLAB ICD), reserve the MCLR pin for reset, and place decoupling capacitors close to VDD/VSS. This part is now considered legacy — verify long-term availability before using in new designs.
This page synthesizes distributor pricing, drop-in alternative cross-references, and practical design notes not typically found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16LF84AT-04/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 PIC16LF84AT-04/SO (same form factor and footprint) — differing in Operating Temperature, Package, Timers, Watchdog Timer, Instruction Set.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF84A-04/SO
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC16LF84A-04I/SO
✅ Drop-In✓ In Stock
$2.21 / Unit
View Datasheet →PIC16LF84A-04/P
✅ Drop-In✓ In Stock
$3.65 / Unit
View Datasheet →PIC16LF83-04/P
✅ Drop-In✓ In Stock
$2.2 / Unit
View Datasheet →PIC16LF83T-04/SO
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC16LF84AT-04/SO Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC 16F |
| Core Processor | PIC |
| Core Size | 8-bit |
| Max Clock Speed | 4 MHz |
| Program Memory Type | Flash |
| Program Memory Size | 1.75 KB (1K x 14) |
| RAM Size | 68 x 8 bytes |
| EEPROM Size | 64 x 8 bytes |
| Number of I/O | 13 |
| Supply Voltage (VDD) | 2.0 V to 5.5 V |
| Oscillator Type | External |
| Package | 18-SOIC (0.295", 7.50mm width) |
| Mounting Type | Surface Mount |
| Operating Temperature | 0 °C to +70 °C |
| Peripherals | POR, WDT |
| Instruction Cycle Time | 200 ns @ 4 MHz |
| Instruction Set | 35 instructions, 14-bit |
| Packaging | Tape & Reel (T suffix) |
| RoHS | Compliant |
PIC16LF84AT-04/SO Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (digital I/O) |
| Pin 2 | RA3 — Port A bit 3 (digital I/O) |
| Pin 3 | RA4/T0CKI — Port A bit 4 / Timer0 clock input (open-drain) |
| Pin 4 | MCLR — Master Clear (reset) input, active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Port B bit 0 / External interrupt input |
| Pin 7 | RB1 — Port B bit 1 (digital I/O) |
| Pin 8 | RB2 — Port B bit 2 (digital I/O) |
| Pin 9 | RB3 — Port B bit 3 (digital I/O) |
| Pin 10 | RB4 — Port B bit 4 (digital I/O) |
| Pin 11 | RB5 — Port B bit 5 (digital I/O) |
| Pin 12 | RB6 — Port B bit 6 (digital I/O / ICSP clock) |
| Pin 13 | RB7 — Port B bit 7 (digital I/O / ICSP data) |
| Pin 14 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock in |
| Pin 17 | RA0 — Port A bit 0 (digital I/O) |
| Pin 18 | RA1 — Port A bit 1 (digital I/O) |
Typical Applications
PIC16LF84AT-04/SO is suitable for 6 applications: Hobbyist Electronics & Education Platforms, Simple Sensor Interface Module, Low-Cost Consumer Appliance Controller, Replacement of Discrete Logic, Embedded Control Nodes (Legacy Maintenance), Educational Development Board Core MCU.
Hobbyist Electronics & Education Platforms
The PIC16LF84AT-04/SO has been a foundational teaching platform for embedded systems education and DIY electronics for over two decades. Its simple architecture (35 instructions), built-in EEPROM for storing student projects, and broad hobbyist ecosystem (PICkit programmers, MPLAB X IDE tutorials, countless online examples) make it the de-facto introductory 8-bit MCU. The 18-SOIC package fits standard 0.1" breakout boards used in electronics education. With 1.75 KB Flash and 13 I/O, students can implement complete projects such as digital thermometers, reaction timers, or traffic-light controllers on a single chip. The 2.0 V to 5.5 V supply range lets the same board run from 3.3 V or 5 V logic. While production designs should migrate to PIC16F1xxx, the PIC16LF84A remains the canonical educational MCU for learning RISC, assembly, and embedded C fundamentals.
Recommended
Simple Sensor Interface Module
For low-cost sensor interface applications such as temperature, humidity, or contact-closure sensing, the PIC16LF84AT-04/SO provides a complete microcontroller solution with on-chip non-volatile storage. Its 64 bytes of EEPROM can hold calibration constants, sensor IDs, or configuration parameters that survive power cycles — eliminating the need for external EEPROM chips. The 13 digital I/O pins interface directly to sensors, LEDs, and UART lines for serial reporting. The 4 MHz clock rate is more than adequate for polled sensor reading at 1 Hz to 1 kHz rates typical in environmental monitoring. The 2.0 V minimum supply supports 2xAA battery operation, and the nanoWatt sleep modes extend battery life for unattended sensor nodes. Commercial temperature range (0 °C to +70 °C) suits indoor climate sensors and HVAC peripherals.
Recommended
Low-Cost Consumer Appliance Controller
The PIC16LF84AT-04/SO suits cost-sensitive consumer appliance control applications such as small kitchen appliances, fan speed controllers, LED decorative lighting sequencers, or simple remote-control receivers. Its Flash memory enables last-minute firmware customization during production without mask ROM charges, and the integrated EEPROM stores user settings (timer values, mode preferences) that persist across power cycles. The 18-SOIC wide-body package has generous pin spacing for hand-soldering and rework — important for low-volume appliance manufacturing. With 4 MHz operation and the standard 35-instruction RISC core, the device executes control loops in under 1 µs, sufficient for slow mechanical actuators and relay sequencing. The low-voltage 2.0 V capability also enables direct 3.3 V operation from USB or wall adapters.
Recommended
Replacement of Discrete Logic
Designers can replace dozens of discrete 74-series logic chips with a single PIC16LF84AT-04/SO for custom sequencing, glue logic, or state-machine applications. A 13-I/O PIC16LF84A can replace entire boards of combinational and sequential logic while adding programmability. The Flash memory enables late-stage design changes without PCB rework, and the 64-byte EEPROM stores state across power cycles. At 4 MHz the PIC16LF84A executes instructions every 200 ns, easily outpacing mechanical relays, displays, and most human-interface devices. This application is common in legacy industrial equipment retrofits, custom test fixtures, and one-off control boxes where a programmable part reduces PCB area and component count compared to hard-wired logic.
Recommended
Embedded Control Nodes (Legacy Maintenance)
The PIC16LF84AT-04/SO is frequently used as a service replacement part for legacy industrial equipment, HVAC controllers, vending machines, and building automation panels designed in the late 1990s and 2000s. Its active lifecycle status as of 2026-09-25 means authorized distributors (DigiKey, Mouser, Microchip Direct) still stock production reels, supporting maintenance of installed equipment without redesign. The 18-SOIC footprint, 13-I/O configuration, and pin-compatible silicon across the PIC16F84A family make it a true drop-in for field replacement. For long-term support programs and obsolescence management, Microchip's product longevity commitments generally extend PIC16 legacy parts well beyond typical industrial equipment service life (15-20 years).
Recommended
Educational Development Board Core MCU
Universities, technical schools, and hobbyist kit vendors frequently use the PIC16LF84AT-04/SO as the central MCU on low-cost development boards (such as the classic K8048 or equivalent). Its combination of Flash, RAM, EEPROM, watchdog, and 13 I/O provides a complete teaching platform for assembly language programming, interrupt handling, and peripheral interfacing without external components. The 18-SOIC package fits standard 0.1" pitch breakout boards, and PICkit programmers connect through the ICSP interface for in-circuit debugging. Educational boards typically expose LEDs, pushbuttons, UART, and I/O headers — fully supported by the PIC16LF84A's capabilities. While Microchip has introduced newer educational targets (PIC16F180xx, Curiosity boards), the PIC16F84A remains in active use in textbooks and curricula worldwide.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF84AT-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF84A-04/SO | PIC16LF84A-04I/SO | PIC16LF83T-04/SO |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC | 18-SOIC — same | 18-SOIC — same | 18-SOIC — same |
| Program Memory (Flash) | 1.75 KB | 1.75 KB | 1.75 KB | 0.875 KB (-50%) |
| RAM | 68 bytes | 68 bytes | 68 bytes | 36 bytes (-47%) |
| EEPROM | 64 bytes | 64 bytes | 64 bytes | None (0 bytes) |
| Max Clock Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Operating Voltage | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| Operating Temperature | 0 °C to +70 °C | 0 °C to +70 °C | -40 °C to +85 °C (industrial) | 0 °C to +70 °C |
Key Differentiators
- Low-voltage 2.0 V minimum supply (LF family) (vs PIC16F84A-04/SO (standard F variant))
- Commercial-grade temperature variant (vs PIC16LF84A-04I/SO (industrial variant))
- Full 1.75 KB Flash + 64 B EEPROM (vs PIC16LF83T-04/SO (predecessor))
Design Notes
Place a 100 nF decoupling capacitor as close as possible between VDD (pin 14) and VSS (pin 5) on the PIC16LF84AT-04/SO. For battery-powered designs, add a 10 µF bulk capacitor at the supply rail to handle inrush from the internal brown-out reset circuit. The nanoWatt sleep mode drops current to microampere levels but requires careful peripheral disable sequencing to avoid spurious wake-ups. Estimated: at 4 MHz active, typical supply current is 2-4 mA; in sleep mode it drops below 1 µA per the datasheet electrical characteristics.
Route the MCLR pin (pin 4) with a short trace and place the pull-up resistor (typically 10 kΩ) within 5 mm of the pin to prevent spurious resets from EMI. For ICSP programming, expose RB6/RB7 (pins 12/13), VDD, VSS, and MCLR on a 0.1" header for PICkit connection. Keep the crystal or resonator (if used) within 10 mm of OSC1/OSC2 (pins 16/15) and guard with a ground plane to minimize radiated noise on adjacent analog or RF circuits.
Do not assume the PIC16LF84AT-04/SO and PIC16F84A-04/SO are interchangeable across the full voltage range: the LF variant operates down to 2.0 V, while the standard F84A requires 4.0 V minimum. Also note that RA4 (pin 3) is open-drain and requires a pull-up resistor for high-side driving. Configuration bits (fuses) such as WDT enable, code protect, and oscillator mode must be set explicitly in source code — leaving them at default values can cause watchdog resets or execution failures.
Compliance Information
RoHS compliant per Microchip product page and DigiKey listing. Not AEC-Q100 qualified — automotive applications should use AEC-Q100-qualified PIC16 variants. Lead-free termination per JEDEC J-STD-020 MSL classification.
