PIC16LF84A-04I/SS - 4MHz 1.75KB Flash 8-bit MCU | Microchip
MPN: PIC16LF84A-04I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.54 | $2.54 |
| 10 | $2.3 | $23.00 |
| 100 | $1.95 | $195.00 |
| 500 | $1.7 | $850.00 |
| 1,000 | $1.45 | $1,450.00 |
PIC16LF84A-04I/SS Overview
An 8-bit microcontroller (MCU) is a single-chip computer built around an 8-bit data path, on-chip program memory, on-chip data RAM, and a small set of peripheral registers. It belongs to the broader hierarchy of embedded computing devices: microcontroller -> microprocessor with peripherals -> CPU; it sits below 16-bit and 32-bit MCUs in raw throughput but above purely hardware state machines in flexibility. The PIC16F8X family, including the PIC16LF84A, is widely taught in introductory embedded courses because it has only 35 instructions, an 8-level hardware stack, and a Harvard architecture that separates program and data buses.
The LF (low-power) variant operates across 2.0 V to 5.5 V supply and offers brown-out reset, a programmable watchdog timer, an on-chip 8-bit timer/counter (TMR0) with 8-bit prescaler, and 64 bytes of non-volatile EEPROM data memory. The /SS suffix denotes the 20-pin SSOP package, while the -04 speed grade marks a 4 MHz maximum oscillator input and the I suffix indicates the industrial temperature range of -40 C to +85 C. The 20-pin SSOP provides 13 I/O plus VDD, VSS, MCLR and OSC1/OSC2 pins.
Typical applications include battery-powered sensor nodes, consumer appliance controllers, hobby and education boards, low-cost user-interface controllers, and small logic-replacement designs that benefit from in-system reprogrammability. When designing with this device, place a 100 nF decoupling capacitor close to VDD and route the MCLR pin through a 10 kohm pull-up to VDD to allow clean in-circuit serial programming. Avoid leaving unused I/O pins floating - configure them as outputs to minimize current draw in sleep mode.
Drop-in alternatives for PIC16LF84A-04I/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-04I/SS (same form factor and footprint) — differing in Package, Timers, Core Architecture, Watchdog Timer, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F84A-04I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LF84A-04I/SO
✅ Drop-In✓ In Stock
$2.21 / Unit
View Datasheet →PIC16LF84A-04/SS
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →PIC16F84A-20I/SS
✅ Drop-In✓ In Stock
$1.65 / Unit
View Datasheet →PIC16LF84AT-04I/SS
✅ Drop-In✓ In Stock
$1.65 / Unit
View Datasheet →PIC16F628A-I/SS
✅ Drop-In✓ In Stock
$1.41 / Unit
View Datasheet →PIC16LF84A-04I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC RISC, 8-bit Harvard |
| Program Memory | 1.75 KB (1K x 14) Flash |
| Data SRAM | 68 bytes |
| EEPROM Data Memory | 64 bytes |
| Maximum Clock Input | 4 MHz |
| Instruction Cycle Time | 200 ns @ 4 MHz |
| Number of Instructions | 35 single-word |
| I/O Pins | 13 |
| Timers | TMR0 8-bit with prescaler |
| Watchdog Timer | Yes (software enabled) |
| Supply Voltage (LF) | 2.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (industrial) |
| Package | 20-pin SSOP (5.30 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| In-Circuit Programming | ICSP via RB6/RB7 |
| Hardware Stack | 8-level |
PIC16LF84A-04I/SS Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 3 | RA4/T0CKI — Bidirectional I/O port A bit 4 / TMR0 clock input |
| Pin 4 | MCLR/VPP — Master Clear (active low reset) / programming voltage input |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Bidirectional I/O port B bit 0 / external interrupt input |
| Pin 7 | RB1 — Bidirectional I/O port B bit 1 |
| Pin 8 | RB2 — Bidirectional I/O port B bit 2 |
| Pin 9 | RB3 — Bidirectional I/O port B bit 3 |
| Pin 10 | RB4 — Bidirectional I/O port B bit 4 |
| Pin 11 | RB5 — Bidirectional I/O port B bit 5 |
| Pin 12 | RB6 — Bidirectional I/O port B bit 6 / ICSP clock |
| Pin 13 | RB7 — Bidirectional I/O port B bit 7 / ICSP data |
| Pin 14 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| Pin 15 | OSC2/CLKOUT — Oscillator crystal output / CLKOUT |
| Pin 16 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 17 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 18 | RA1 — Bidirectional I/O port A bit 1 |
| Pin 19 | NC — Not connected (per datasheet, reserved) |
| Pin 20 | NC — Not connected (per datasheet, reserved) |
Typical Applications
PIC16LF84A-04I/SS is suitable for 6 applications: Battery-Powered Sensor Nodes, Consumer Appliance User-Interface Controllers, Educational and Hobby Development Boards, Discrete Logic Replacement and Glue Logic, Automotive Interior Lighting Controllers (non-safety), Industrial Control Module (Modbus RTU Slave).
Battery-Powered Sensor Nodes
The PIC16LF84A-04I/SS is well-suited to battery-powered sensor nodes because its 2.0 V to 5.5 V supply range enables direct operation from a single lithium coin cell or two alkaline cells across the full discharge curve, eliminating boost converters and their quiescent current. The 35-instruction RISC core consumes microamp-level sleep current, allowing months of battery life when the node wakes periodically to read a temperature or motion sensor. The 1.75 KB Flash and 64-byte EEPROM comfortably hold application firmware plus per-device calibration constants stored across power cycles. In a typical design, the MCU sleeps at <1 uA, wakes via watchdog timeout to read the sensor, transmits a packet over a UART-driven radio, and returns to sleep - all on a 3 V coin cell. Compared to discrete logic, the integrated brown-out reset and watchdog timer protect the node from brown-outs and code lockups in unattended deployments.
Recommended
Consumer Appliance User-Interface Controllers
The PIC16LF84A-04I/SS drives cost-effective user-interface panels in coffee machines, microwave ovens, washing machines and small kitchen appliances where 13 I/O pins easily accommodate a 4x3 keypad matrix plus 5-7 LED indicators. The 200 ns instruction cycle handles button-debounce loops and LED-multiplex refresh without processor loading, and the in-circuit serial programming (ICSP) interface lets the manufacturer update firmware on the assembly line or in service centers. The PIC16F8X instruction set is so compact (only 35 single-word opcodes) that firmware fits in the 1.75 KB Flash even with rotary-encoder decoding and seven-segment display driving. The 8-level hardware stack is adequate for the interrupt-driven keypad scan routines typical of these appliances, and the on-chip EEPROM stores user-set clock values and last-mode memory across power loss.
Recommended
Educational and Hobby Development Boards
The PIC16LF84A-04I/SS is the canonical microcontroller taught in introductory embedded systems courses and used in countless hobby projects because the 35-instruction RISC core can be learned in a single lab session. The 4 MHz instruction cycle and 200 ns execution time make timing loops directly observable on an oscilloscope, and the 13 I/O pins provide enough headroom for breadboard-based experiments with LEDs, pushbuttons, 7-segment displays and simple serial interfaces. The ICSP programming via RB6/RB7 allows students to debug iteratively without removing the part from the breadboard, dramatically reducing hardware damage. The SSOP-20 footprint also accepts SOIC-20 adapter boards, broadening prototyping flexibility for both surface-mount and through-hole training labs. Its 1.75 KB Flash capacity hosts full C-compiler output for libraries and bootloader code, yet small enough to teach hand-assembled instruction exercises.
Recommended
Discrete Logic Replacement and Glue Logic
Designers use the PIC16LF84A-04I/SS to replace banks of 74-series TTL or HC logic chips that implement sequencers, counters, latches and state machines in legacy designs. With 13 I/O pins, 64 bytes EEPROM for state storage and 200 ns response, a single PIC16LF84A-04I/SS can replace 3-6 SSI/MSI logic packages, simplifying PCB layout and BOM cost while adding programmable flexibility for last-minute design changes. The 2.0-5.5 V supply range makes the part compatible with both 3.3 V and 5 V logic families, simplifying interface to modern low-voltage peripherals. The watchdog timer and brown-out reset add the safety features absent in pure-logic sequencers, while ICSP lets the engineer iterate on the state machine without re-spinning the PCB. Code reuse is high because the 35-instruction set is straightforward to hand-code for simple sequencer replacements.
Recommended
Automotive Interior Lighting Controllers (non-safety)
The PIC16LF84A-04I/SS supports interior ambient lighting controllers for door panels, footwells, and dashboard accent LEDs in non-safety automotive applications where the industrial -40 to +85 C temperature range is acceptable. The 13 I/O pins can PWM-drive 4-6 LED channels via MOSFET drivers while reading rotary brightness encoders and pushbutton inputs. The 1.75 KB Flash holds a comfortable fade-pattern library plus button-debounce state machines, and the on-chip EEPROM stores user preferences such as last brightness across battery disconnects. The 2.0-5.5 V supply tolerates cranking transients on 12 V automotive rails when fed through a low-dropout regulator. For safety-critical functions such as airbag controllers or ADAS, the AEC-Q100-qualified PIC16F family members are the correct choice instead.
Recommended
Industrial Control Module (Modbus RTU Slave)
The PIC16LF84A-04I/SS implements a low-cost Modbus RTU slave node on industrial RS-485 links where the 4 MHz instruction cycle is more than adequate for 9600-38400 baud bit-banged UART communication. With 13 I/O, the part simultaneously drives an RS-485 transceiver enable line, monitors 4-6 digital inputs, and controls 2-3 relay outputs while maintaining the Modbus state machine in 1.75 KB Flash. The 64-byte EEPROM stores the device address, baud rate and last-state holding registers across power cycles, while the 68-byte RAM holds the Modbus PDU and input image. The industrial -40 to +85 C temperature rating matches most factory-floor enclosure environments. The watchdog timer automatically recovers the slave from transient EMI-induced code lockups typical of industrial settings, and ICSP enables firmware updates in the field without removing the module from the DIN rail.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF84A-04I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F84A-04I/SS | PIC16LF84A-04/SS | PIC16F84A-20I/SS | PIC16LF84AT-04I/SS | PIC16F628A-I/SS |
|---|---|---|---|---|---|---|
| Package | 20-SSOP | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Supply Voltage | 2.0 V to 5.5 V (LF) | 4.0 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 | 3.0 V to 5.5 V |
| Max Clock | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 4 MHz | 20 MHz |
| Flash Program Memory | 1.75 KB | 1.75 KB | 1.75 KB | 1.75 KB | 1.75 KB | 3.5 KB |
| Data SRAM | 68 bytes | 68 bytes | 68 bytes | 68 bytes | 68 bytes | 224 bytes |
| EEPROM | 64 bytes | 64 bytes | 64 bytes | 64 bytes | 64 bytes | 128 bytes |
| I/O Pins | 13 | 13 | 13 | 13 | 13 | 16 |
| Temperature Range | -40 C to +85 C (I) | -40 C to +85 C (I) | 0 C to +70 C | -40 C to +85 C (I) | -40 C to +85 C (I) | -40 C to +85 C (I) |
Key Differentiators
- Wider supply-voltage range enables single-cell battery operation (vs PIC16F84A-04I/SS)
- Industrial -40 to +85 C temperature range (vs PIC16LF84A-04/SS)
- Five-times faster clock headroom when stepping up (vs PIC16F84A-04I/SS)
- Enhanced peripheral path without changing PCB layout (vs PIC16F628A-I/SS)
Design Notes
Decouple VDD (pin 14) with a 100 nF ceramic capacitor placed within 5 mm of the package, plus a 10 uF bulk capacitor at the regulator output. The PIC16LF84A-04I/SS operates from 2.0 V to 5.5 V, so a low-dropout regulator such as MCP1700 is appropriate for cell-powered designs. Add a 10 kohm pull-up on MCLR/VPP (pin 4) to enable reliable ICSP programming - leaving MCLR floating is a common cause of intermittent reset on breadboard prototypes.
Route the OSC1/OSC2 traces (pins 15-16) short and symmetric, and place the crystal/ceramic resonator and its load capacitors (typically 15-33 pF) within a few millimeters of the pins to minimize parasitic capacitance. When using an external clock source, drive OSC1 with a CMOS-level signal and leave OSC2 floating. Keep clock traces away from switching power or relay lines to prevent injection of noise into the 200 ns instruction cycle timing.
Do not leave unused I/O pins floating - configure them as outputs (write 0 to the TRIS register) to draw a defined current and avoid spurious input transitions that can wake the part from sleep. Never drive MCLR with a slow-rising signal; the brown-out reset works correctly only with a fast-edged reset. When using ICSP, ensure the programmer's VPP voltage does not exceed 13.5 V or the part may enter high-voltage programming mode unintentionally. The watchdog timer must be cleared (CLRWDT) within the prescaler window or the device will reset - document this behavior in firmware comments.
RB0 doubles as the external interrupt (INT) input and is the only edge-sensitive interrupt source on the PIC16LF84A-04I/SS. Configure OPTION_REG<INTEDG> for rising or falling edge selection. When reading mechanical switches, software debounce on the order of 5-20 ms is required because the input Schmitt trigger has a hysteresis of approximately 0.4 V but no time-domain filtering. Use the on-chip TMR0 prescaler to extend the watchdog timer to its maximum 2.3 s timeout for sleep-mode wakeup.
Compliance Information
RoHS-compliant per Microchip product page and DigiKey listing. Lead-free NiPdAu finish. Halogen-free per Microchip environmental compliance. Not AEC-Q100 qualified - this part targets industrial and consumer markets. For AEC-Q100 applications use qualified PIC16F family members. Conflict-minerals declaration available on request through Microchip.
