PIC16LF84A-04/SO - 4MHz 8-Bit Flash MCU, 1.75KB | Microchip
MPN: PIC16LF84A-04/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.66 | $26.60 |
| 100 | $2.36 | $236.00 |
| 500 | $2.13 | $1,065.00 |
| 1,000 | $1.95 | $1,950.00 |
PIC16LF84A-04/SO Overview
A microcontroller (MCU) is a single-chip computer containing a CPU, RAM, non-volatile program memory, and programmable I/O peripherals. The PIC16F family belongs to the 8-bit microcontroller hierarchy (8-bit MCU -> RISC MCU -> embedded controller -> semiconductor), with the 'LF' prefix denoting the low-voltage F-process technology optimized for battery-powered and energy-harvesting designs. PIC microcontrollers are widely used in education and low-cost embedded systems thanks to their deterministic architecture and free MPLAB X toolchain.
Key features of the PIC16LF84A-04/SO include a 4 MHz maximum oscillator frequency, 13 digital I/O pins with individual direction control, a 14-bit instruction word, an 8-bit timer/counter (Timer0) with 8-bit prescaler, an 8-bit Timer2 with prescaler and postscaler, a watchdog timer with its own on-chip RC oscillator, and an ICD (In-Circuit Debugger) interface on higher-pin-count variants. The 18-pin SOIC package provides a 7.5 mm (0.300 inch) body width suitable for hand-soldered prototypes and surface-mount production.
The device uses a Harvard architecture with separate program and data buses, executing one instruction per four clock cycles. Internal RC oscillator options support cost-sensitive designs without external crystals. The 64-byte EEPROM is byte-erasable and rated for typical endurance of 1 million write cycles per cell, making the part suitable for applications requiring non-volatile parameter storage without external serial EEPROMs.
Typical applications include hobbyist electronics projects, automotive interior accessories (sensor interfaces, simple lighting controllers), industrial control panels (push-button interfaces, LED indicators, low-speed relay drivers), educational development boards, battery-powered sensor nodes, low-rate UART-based data logging, and replacement of legacy PIC16F84 designs in production. The wide 2.0-5.5V range supports both 3.3V and 5V systems.
When designing with this MCU, note that the LF84A-04 variant is the 4 MHz grade; the -04I and -10 suffixes denote industrial temperature range (or 10 MHz). Ensure the in-circuit serial programming (ICSP) header is accessible for field firmware updates, and that the MCLR pin is properly pulled up through a resistor to VDD. This page consolidates distributor pricing, pin-compatible alternatives, and engineering notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16LF84A-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 PIC16LF84A-04/SO (same form factor and footprint) — differing in Package, Operating Temperature, Timers, MSL Level, Peripherals.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF84A-04I/SO
✅ Drop-In✓ In Stock
$2.21 / Unit
View Datasheet →PIC16LF84A-04E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F84A-04/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF84A-20/SO
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16F84A-04/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF84A-04/SO Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC 16F |
| Core Processor | PIC |
| Core Size | 8-Bit |
| Maximum Clock Speed | 4 MHz |
| Program Memory Size | 1.75 KB (1K x 14 words) Flash |
| RAM Size | 68 bytes |
| EEPROM Size | 64 bytes |
| Number of I/O Pins | 13 |
| Supply Voltage Range | 2.0 V to 5.5 V |
| Operating Temperature Range | 0 C to +70 C (commercial, -04 grade) |
| Package / Case | 18-SOIC (SO, 0.300 inch body) |
| Mounting Type | Surface Mount |
| Oscillator Type | External (crystal/resonator) or internal RC |
| Peripherals | Brown-out Detect, Watchdog Timer, Timer0, Timer1, Timer2 |
| Connectivity | ICSP (In-Circuit Serial Programming) |
| Instruction Set Architecture | PIC mid-range, 35 instructions, 14-bit word |
| Data Converters | None (no ADC on this part) |
| Program Memory Type | Flash (self-programmable) |
| RoHS Status | Compliant |
PIC16LF84A-04/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional digital I/O pin |
| Pin 2 | RA3 — Bidirectional digital I/O pin |
| Pin 3 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 4 | MCLR — Master Clear (reset) input, active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Digital I/O / External interrupt input |
| Pin 7 | RB1 — Bidirectional digital I/O pin |
| Pin 8 | RB2 — Bidirectional digital I/O pin |
| Pin 9 | RB3 — Bidirectional digital I/O pin |
| Pin 10 | RB4 — Bidirectional digital I/O / interrupt-on-change |
| Pin 11 | RB5 — Bidirectional digital I/O / interrupt-on-change |
| Pin 12 | RB6 — Bidirectional digital I/O / interrupt-on-change |
| Pin 13 | RB7 — Bidirectional digital I/O / interrupt-on-change |
| Pin 14 | VDD — Positive supply (2.0V to 5.5V) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock output |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 17 | RA0 — Bidirectional digital I/O pin |
| Pin 18 | RA1 — Bidirectional digital I/O pin |
Typical Applications
PIC16LF84A-04/SO is suitable for 6 applications: Educational Microcontroller Development Boards, Battery-Powered Sensor Nodes, Industrial Control Panel Interfaces, Automotive Interior Accessories, Replacement for Legacy PIC16F84 Designs, Low-Rate UART Data Logging.
Educational Microcontroller Development Boards
The PIC16LF84A-04/SO is the canonical MCU for PIC microcontroller training courses thanks to its simple 35-instruction mid-range architecture and free MPLAB X toolchain. The 2.0-5.5V supply range lets students power boards from a single USB 5V rail or 3.3V regulator without brown-out issues. The 4 MHz instruction rate is fast enough to demonstrate polling, interrupts, and timer-based multitasking in introductory embedded courses while keeping timing analysis tractable by hand. Its 18-SOIC package also supports easy breadboard adapters and through-hole prototyping.
Recommended
Battery-Powered Sensor Nodes
The PIC16LF84A-04/SO's 2.0V minimum supply voltage and sub-1 microamp sleep current make it well-suited for long-life battery-powered wireless sensor endpoints. A typical node wakes on a watchdog timer interrupt every few seconds, reads an external sensor, transmits a short packet over UART, and returns to sleep - drawing average current under 10 microamps and achieving multi-year life from two AA cells. The 64-byte EEPROM provides non-volatile storage for calibration constants and node IDs across battery replacements.
Recommended
Industrial Control Panel Interfaces
In factory control panels, the PIC16LF84A-04/SO scans up to 13 push-buttons or selector switches and drives LED indicators or low-power relays, replacing discrete logic with deterministic firmware. The 4 MHz speed handles human-input debounce and indicator multiplexing comfortably, and the brown-out reset plus watchdog timer ensure reliable recovery from supply glitches common on industrial 24V rails. The 18-SOIC package saves board space versus legacy 40-pin PLC modules and simplifies EMC compliance testing.
Recommended
Automotive Interior Accessories
For non-safety automotive interior accessories (interior lighting controllers, ambient LED drivers, simple sensor interfaces), the PIC16LF84A-04E/SO variant operates over the full automotive -40C to +125C range and tolerates 12V battery transients when paired with proper supply regulation. Its 1.75 KB Flash comfortably stores state-machine firmware for lighting sequences and switch debouncing. The mid-range PIC instruction set is well-supported by Microchip's automotive-qualified toolchain and validation flow.
Recommended
Replacement for Legacy PIC16F84 Designs
The PIC16LF84A-04/SO is the recommended upgrade path for legacy products originally built around the now-discontinued PIC16F84, offering more program memory (1.75 KB Flash vs 1.75 KB Flash with self-programmability), faster 4 MHz operation, and a 2.0-5.5V supply. Existing assembly source compiles and runs unmodified thanks to identical 35-instruction mid-range architecture, eliminating costly firmware revalidation. The 18-SOIC package pinout is byte-identical to the PIC16F84, so no PCB rework is needed.
Recommended
Low-Rate UART Data Logging
The PIC16LF84A-04/SO can serve as a low-cost UART-to-UART bridge or simple data logger, using Timer0 for periodic sampling of digital inputs and writing event records to its 64-byte EEPROM or streaming them over UART at 9600 baud. At 4 MHz the UART module supports up to 250 kbps baud, far above any data-logging requirement. The brown-out detect and watchdog timer ensure log integrity through power-cycle and brown-out events common in remote deployments without UPS backup.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF84A-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF84A-04I/SO | PIC16LF84A-04E/SO | PIC16F84A-04/SO | PIC16LF84A-20/SO | PIC16F84A-04/P |
|---|---|---|---|---|---|---|
| Package | 18-SOIC | 18-SOIC - same | 18-SOIC - same | 18-SOIC - same | 18-SOIC - same | 18-PDIP - through-hole |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 4 MHz |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 4.0 V to 5.5 V | 2.0 V to 5.5 V | 4.0 V to 5.5 V |
| Operating Temperature Range | 0 C to +70 C | -40 C to +85 C | -40 C to +125 C | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C |
| Flash Program Memory | 1.75 KB | 1.75 KB | 1.75 KB | 1.75 KB | 1.75 KB | 1.75 KB |
| RAM / EEPROM | 68 B / 64 B | 68 B / 64 B | 68 B / 64 B | 68 B / 64 B | 68 B / 64 B | 68 B / 64 B |
| Instruction Set | PIC mid-range (35 instructions) | PIC mid-range (35 instructions) | PIC mid-range (35 instructions) | PIC mid-range (35 instructions) | PIC mid-range (35 instructions) | PIC mid-range (35 instructions) |
| Mounting Type | Surface Mount (SOIC) | Surface Mount (SOIC) | Surface Mount (SOIC) | Surface Mount (SOIC) | Surface Mount (SOIC) | Through-Hole (PDIP) |
Key Differentiators
- Wider supply voltage range (2.0 V minimum) than standard F84A (vs PIC16F84A-04/SO)
- Higher throughput option available in same package (vs PIC16LF84A-04/SO)
- Commercial temperature grade optimized for cost-sensitive consumer products (vs PIC16LF84A-04I/SO)
Design Notes
The PIC16LF84A-04/SO's 2.0V minimum supply voltage enables direct operation from a single lithium coin cell (3V nominal) or two alkaline AA cells. Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of the VDD pin (14) and VSS pin (5), plus a bulk 10 uF tantalum or aluminum polymer at the regulator output. The internal brown-out reset is factory-set; verify the BOR threshold (typically 2.0V for the LF variant) matches your battery's end-of-life voltage to maximize usable capacity without spurious resets.
Route the ICSP clock and data signals (RB6 and RB7) with short traces and avoid routing noisy switching signals adjacent to them - these pins carry the in-circuit serial programming protocol at up to 5 MHz and are susceptible to EMI coupling that can cause programming failures. Place the MCLR pull-up resistor (typically 10 kohm) within 5 mm of pin 4 and ensure the ICSP connector's VPP line includes a series resistor (typically 10 kohm) to limit inrush during programming.
Do not assume the internal RC oscillator timing is accurate enough for UART communication - the factory-calibrated HFINTOS drift can exceed +/-5% across temperature, causing baud-rate errors above 9600 bps. For UART use, choose a crystal or ceramic resonator on OSC1/OSC2 and configure the FOSC configuration fuse accordingly. Also note that configuration bits are NOT erased by a bulk Flash erase; if you change oscillator settings in firmware, you must reprogram them explicitly via ICSP.
Keep the crystal or resonator traces to OSC1 (pin 16) and OSC2 (pin 15) short (under 10 mm) and surround them with a ground pour to minimize stray capacitance and noise pickup. Add small (10-22 pF) load capacitors from each oscillator pin to VSS, with values chosen per the crystal manufacturer's CL specification. For 4 MHz designs, ground the can of through-hole crystals directly to VSS to suppress radiated emissions during oscillator startup.
Compliance Information
RoHS compliant per Microchip product page. The standard PIC16LF84A-04/SO is NOT AEC-Q100 qualified; the PIC16LF84A-04E/SO extended-temperature variant is typically used for automotive interior accessories but is also not AEC-Q100 qualified.
