PIC16LF84A-04/SS - 8-bit 4MHz 1.75KB Flash MCU 20-SSOP | Microchip
MPN: PIC16LF84A-04/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.08 | $3.08 |
| 10 | $2.85 | $28.50 |
| 100 | $2.55 | $255.00 |
| 500 | $2.3 | $1,150.00 |
| 1,000 | $2.1 | $2,100.00 |
PIC16LF84A-04/SS Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, RAM, I/O peripherals, and timers onto one silicon die. The PIC16 family belongs to the mid-range 8-bit tier in the broader taxonomy: 8-bit MCU -> microcontroller -> embedded processor -> semiconductor. Within the PIC portfolio, mid-range parts are designed for low-power, cost-sensitive applications and serve as the workhorse for consumer, industrial, and educational designs.
Key features include a wide operating voltage range of 1.8 V to 3.6 V, low-power CMOS technology suitable for battery operation, an internal oscillator option on the LF variant, a 10-bit timer/counter, a Watchdog Timer with on-chip RC oscillator, in-circuit serial programming (ICSP), and 8-bit parallel slave port. The device supports in-system programming through two pins, allowing firmware updates after PCB assembly.
The PIC16LF84A architecture separates program and data buses (Harvard), and the LF variant extends supply down to 1.8 V for portable and battery-powered designs. Its 4 MHz maximum clock rate, 14-bit instruction word, and a deep 8-level hardware stack give it predictable interrupt performance for time-critical control loops.
Typical applications include low-power remote sensors, battery-powered consumer devices, HVAC controls, simple motor control, LED drivers, learning platforms, hobbyist projects, and replacement of legacy PIC16F84A designs in industrial controllers. The 20-SSOP footprint offers a compact alternative to the 18-pin DIP/PDIP and 18-pin SOIC variants of the same die.
When designing, note that the LF version's 1.8 V minimum supply is required for low-voltage operation; the standard 'F' (non-L) variant operates at 2.0 V to 5.5 V. Pin-compatible migration between 18-pin and 20-pin SSOP packages requires PCB adaptation due to differing pin counts.
This page synthesizes distributor stock, same-family Microchip alternatives, and practical design notes not aggregated in the manufacturer datasheet alone.
Drop-in alternatives for PIC16LF84A-04/SS — 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/SS (same form factor and footprint) — differing in Package, Timers, Watchdog Timer, Operating Temperature, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF84A-04I/SS
✅ Drop-In✓ In Stock
$1.45 / Unit
View Datasheet →PIC16LF84AT-04/SS
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC16F84A-04/SS
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →PIC16LF84A-04/SO
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC16LF84A-04/P
✅ Drop-In✓ In Stock
$3.65 / Unit
View Datasheet →PIC16LF84A-04/SS Maximum Ratings & Electrical Characteristics
| Core | PIC16 8-bit RISC |
| Instruction Set | 35 single-word instructions |
| Program Memory (Flash) | 1.75 KB (1K x 14 words) |
| RAM | 68 bytes |
| EEPROM Data Memory | 64 bytes |
| Maximum Clock Speed | 4 MHz |
| Instruction Execution Time | 200 ns at 4 MHz |
| Supply Voltage (VDD) | 1.8 V to 3.6 V |
| I/O Pins | 13 |
| Timers | 1 x 8-bit Timer0 with prescaler |
| Watchdog Timer | Yes (with dedicated on-chip RC oscillator) |
| In-Circuit Serial Programming (ICSP) | Yes (2-wire) |
| Parallel Slave Port | Yes (8-bit, PORTB) |
| Operating Temperature Range | 0C to +70C (commercial) |
| Package | 20-pin SSOP |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC16LF84A-04/SS Pin Configuration
| Pin 1 | RA2 — Port A bit 2 / analog/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/VPP — Master Clear reset / programming voltage input |
| 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 / interrupt-on-change |
| Pin 11 | RB5 — Port B bit 5 / interrupt-on-change |
| Pin 12 | RB6/PGC — Port B bit 6 / ICSP clock (ICSPCLK) |
| Pin 13 | RB7/PGD — Port B bit 7 / ICSP data (ICSPDAT) |
| Pin 14 | VDD — Positive supply voltage (1.8 V to 3.6 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 |
| Pin 19 | RA5/SS — Port A bit 5 / slave select (not present on 18-pin DIP variant) |
| Pin 20 | NC — Not connected on this die variant / reserved |
Typical Applications
PIC16LF84A-04/SS is suitable for 6 applications: Battery-Powered Remote Sensor Nodes, HVAC and Building Automation Controllers, Consumer Remote Controls and IR Toys, LED Lighting Controllers and Drivers, Legacy Industrial Control Board Replacement, Educational Microcontroller Training Kits.
Battery-Powered Remote Sensor Nodes
The PIC16LF84A-04/SS is well suited for battery-powered remote sensor nodes because of its 1.8 V to 3.6 V low-voltage supply range and CMOS process. With a 4 MHz clock and CMOS I/O, the part typically draws 1-3 mA active and a few microamps in sleep mode, supporting multi-year coin-cell life in intermittent sampling applications. The 13 digital I/O pins can directly interface temperature, humidity, or PIR sensors without level shifters, and the 64-byte EEPROM stores calibration coefficients that survive battery swaps. Designers wire the Watchdog Timer to the on-chip RC oscillator for autonomous reset behavior, avoiding external supervisory parts.
Recommended
HVAC and Building Automation Controllers
The PIC16LF84A-04/SS fits HVAC zone controllers, thermostats, and building automation I/O expanders where 3.3 V logic is the norm. Its 8-bit Parallel Slave Port on PORTB allows the part to act as an I/O extender on a Modbus or BACnet master controller, offloading keypad scanning, LED multiplexing, and relay drive. The Watchdog Timer with dedicated on-chip RC oscillator prevents lockup in unattended installations. Flash-based firmware supports field updates via ICSP through a service header, allowing HVAC technicians to upgrade sensor tables after installation without desoldering the MCU.
Recommended
Consumer Remote Controls and IR Toys
The PIC16LF84A-04/SS is commonly used in low-cost IR remote controls, educational toys, and consumer appliances because of its 35-instruction RISC simplicity and small 20-SSOP footprint. With 1.75 KB Flash, the part easily fits NEC, RC5, or Sony SIRC IR protocol code plus a user-mode state machine. The LF variant's 1.8 V supply enables direct Li-ion or two-AAA battery operation. The PORTB interrupt-on-change feature wakes the MCU from sleep on any button press, achieving sub-10 uA standby current. PICkit programmers ship with sample code that accelerates hobbyist development.
Recommended
LED Lighting Controllers and Drivers
The PIC16LF84A-04/SS serves as a sequencer for decorative LED strips, addressable pixel tape (WS2811/WS2812), and signage controllers. Its 13 I/O pins drive 8-10 LED channels directly through MOSFET gates, while the 200 ns instruction cycle sustains bit-banged PWM refresh at 30 fps on a 60-pixel strip. The 64-byte EEPROM stores user color presets and animation modes that survive power cycles. Designers use Timer0 with a prescaler to generate the 800 kHz WS2812 reset/data timing without burdening the CPU loop.
Recommended
Legacy Industrial Control Board Replacement
The PIC16LF84A-04/SS is widely specified for legacy industrial control boards where customers maintain spares for 10-15 year service life. The 20-SSOP footprint matches existing PCB land patterns designed in the early 2000s, and the same PIC16F8X instruction set allows drop-in firmware migration. Its 0C to +70C commercial operating range suits indoor control panels and OEM equipment rooms. With 1.75 KB Flash and 68 bytes RAM, the part runs the same ladder-logic-replacement state machines that have shipped in industrial controllers for two decades.
Recommended
Educational Microcontroller Training Kits
The PIC16LF84A-04/SS is a common teaching platform in university microcontroller courses because of its simple RISC architecture and abundant example code. Its 35-instruction set can be learned in a single lab session, while the 1.75 KB Flash is large enough for real assignments like I2C bit-banging, UART polling, and timer-based PWM. The 20-SSOP package fits breakout boards designed for breadboarding, and ICSP allows instructors to flash firmware in class without UV erasers. Student kits commonly ship with PICkit programmers and MPLAB X IDE integration.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF84A-04/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF84A-04I/SS | PIC16LF84AT-04/SS | PIC16F84A-04/SS | PIC16LF84A-04/SO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-SSOP | 20-SSOP | 20-SSOP | 20-SSOP | 18-SOIC |
| Supply Voltage | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 2.0 V to 5.5 V | 1.8 V to 3.6 V |
| Maximum Clock | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Program Memory (Flash) | 1.75 KB (1K x 14) | 1.75 KB | 1.75 KB | 1.75 KB | 1.75 KB |
| RAM | 68 bytes | 68 bytes | 68 bytes | 68 bytes | 68 bytes |
| I/O Pins | 13 | 13 | 13 | 13 | 13 |
| Operating Temperature | 0C to +70C | -40C to +85C | 0C to +70C | 0C to +70C | 0C to +70C |
Key Differentiators
- Low-voltage operation to 1.8 V vs 2.0 V on standard F84A (vs PIC16F84A-04/SS)
- Industrial temperature grade -40C to +85C (vs PIC16LF84A-04/SS (this part, commercial))
- Same die in 20-SSOP compact surface-mount package (vs PIC16LF84A-04/P)
Design Notes
The PIC16LF84A-04/SS draws a few microamps in sleep mode, but VDD decoupling is still mandatory. Place a 100 nF ceramic capacitor between VDD (pin 14) and VSS (pin 5) within 5 mm of the package. For battery applications adding a bulk 10 uF tantalum or ceramic improves brownout recovery. Note that the LF variant's internal EEPROM write current peaks at ~3 mA, so factor headroom into battery impedance calculations.
Keep the ICSP clock (PGC, pin 12) and ICSP data (PGD, pin 13) traces short and routed together; signal integrity directly affects programming reliability. Place MCLR/VPP (pin 4) pull-up (typically 10 kohm) close to the pin, and add a series resistor (around 470 ohm) plus diode to VDD for in-circuit programming isolation when other circuitry drives MCLR. The 20-SSOP fine-pitch pads benefit from a small ground pour under the package to assist thermal dissipation.
The 'LF' prefix is critical: the LF version has a 1.8 V minimum VDD, the non-LF PIC16F84A starts at 2.0 V. Dropping the LF part below 1.8 V causes EEPROM read errors and brownout misbehavior. Avoid confusing the 20-SSOP 'PIC16LF84A-04/SS' with the 18-pin DIP 'PIC16LF84A-04/P' - they share the same die but have different pin counts and pinouts. Programming the wrong part on a 20-pin PCB land pattern will short internal pads to the wrong traces.
Estimated: at 4 MHz clock with a 50 pF/trace capacitance budget on the OSC1/OSC2 lines, total pin capacitance is roughly 20 pF. Use a crystal or ceramic resonator with load capacitance rated between 15 and 33 pF to keep oscillator startup time under 10 ms. For low-power designs using the internal RC oscillator (not present on this die but common on F84A alternatives), trim the OSCCAL register to within 2% for UART timing accuracy.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified; for automotive applications use PIC16F84A-04/SS (industrial) with customer-side qualification.
