PIC16LF84AT-04/SS - 8-bit PIC MCU, 1.75KB Flash, 4MHz, SSOP-20 | Microchip
MPN: PIC16LF84AT-04/SS ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.42 | $2.42 |
| 10 | $2.18 | $21.80 |
| 100 | $1.93 | $193.00 |
| 500 | $1.71 | $855.00 |
| 1,000 | $1.55 | $1,550.00 |
PIC16LF84AT-04/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, peripherals, and I/O into one package. The PIC16F84A belongs to the PIC16 family of 8-bit microcontrollers and sits in the broader taxonomy of microcontrollers -> microprocessors -> semiconductor ICs. Harvard architecture and a 14-bit wide instruction word give this family its single-cycle RISC performance.
Key features include 35 single-word instructions, a hardware 8-bit timer/counter (TMR0) with an 8-bit prescaler, a 10-bit resolution capture/compare/PWM (CCP) peripheral, a watchdog timer with on-chip RC oscillator, an internal 4MHz RC oscillator option, and an ICD (In-Circuit Debugger) interface. The 20-pin SSOP (Shrink Small Outline Package, 0.209 inch / 5.30mm body width) supports surface-mount assembly on compact boards.
The architecture combines a 14-bit instruction word with separate program and data buses (Harvard), allowing instruction fetch and data access to occur in the same cycle. With only 35 single-word instructions to learn, code density and development time are both favorable for low-cost embedded designs. The internal 4MHz oscillator and configurable oscillator modes eliminate the need for external crystals in many low-cost designs, further reducing BOM cost.
Typical applications include consumer appliance controls, sensor interface boards, low-cost industrial controllers, hobbyist/educational projects, replacement of legacy 8051 designs, and battery-powered smart devices where the LF (low-voltage, low-power) silicon is important. The 2.0V minimum supply allows direct operation from a single Li-ion cell when paired with a low-dropout boost regulator.
When designing with this device, ensure decoupling capacitors are placed within 5mm of the VDD pin, and that the MCLR reset circuit follows Microchip's recommended RC network (typically 10k pull-up plus 100nF capacitor). Programming voltages for the high-voltage ICSP mode are not required because this part supports low-voltage in-circuit serial programming (LVP).
This page synthesizes distributor pricing, verified cross-reference data, parametric alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16LF84AT-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 PIC16LF84AT-04/SS (same form factor and footprint) — differing in Package, Operating Temperature, Timers, Watchdog Timer, Supply Voltage (VDD).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LF84A-04I/SS
✅ Drop-In✓ In Stock
$1.45 / Unit
View Datasheet →PIC16LF84A-04/SS
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →PIC16LF84AT-04/SO
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC16F84A-04I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F84A-04/SS
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →PIC16LF84AT-04/SS Maximum Ratings & Electrical Characteristics
| Family | PIC16F8X |
| Core | 8-bit PIC RISC (Harvard) |
| Program Memory Type | Flash |
| Program Memory Size | 1.75 KB |
| RAM Size | 68 bytes |
| EEPROM Size | 64 bytes |
| Maximum Clock Frequency | 4 MHz (LF variant, 2-5.5V) |
| Instruction Cycle | 400 ns at 4 MHz |
| Instruction Set | 35 single-word instructions |
| I/O Pins | 13 |
| Timers | 1 x 8-bit TMR0 with 8-bit prescaler |
| CCP Modules | 1 (Capture / Compare / PWM) |
| Watchdog Timer | Yes (with on-chip RC oscillator) |
| Supply Voltage | 2.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (commercial/industrial) |
| Internal Oscillator | 4 MHz RC (selectable) |
| ICSP / ICD | Yes (LVP and ICD supported) |
| Package | 20-pin SSOP (0.209 inch / 5.30 mm width) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| MSL Level | 1 (unlimited floor life) |
PIC16LF84AT-04/SS 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/VPP — Master Clear reset input / programming voltage |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Port B bit 0 / external interrupt |
| 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 / LVP enable) |
| Pin 10 | RB4 — Port B bit 4 (digital I/O / interrupt-on-change) |
| Pin 11 | RB5 — Port B bit 5 (digital I/O / interrupt-on-change) |
| Pin 12 | RB6 — Port B bit 6 (digital I/O / ICD clock) |
| Pin 13 | RB7 — Port B bit 7 (digital I/O / ICD data) |
| Pin 14 | VSS — Ground reference |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clockout |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 17 | RA7 — Not connected on PIC16F84A (pin reserved) |
| Pin 18 | RA6 — Not connected on PIC16F84A (pin reserved) |
| Pin 19 | RA1 — Port A bit 1 (digital I/O) |
| Pin 20 | RA0 — Port A bit 0 (digital I/O) |
Typical Applications
PIC16LF84AT-04/SS is suitable for 6 applications: Battery-Powered Sensor Nodes, Consumer Appliance Control Boards, Hobbyist and Educational Projects, Replacement of Legacy 8051 Designs, Industrial Low-Cost Controllers, Smart Card and RFID Tag Controllers.
Battery-Powered Sensor Nodes
The PIC16LF84AT-04/SS is well suited for battery-powered wireless or wired sensor nodes because its LF silicon operates down to 2.0 V from a single Li-ion or 2xAA cell, with sub-1 uA sleep current enabling multi-year battery life. Its 13 GPIO easily accommodates an I2C/SPI sensor interface, an interrupt-driven wake-up path, and an LED status indicator on the same die. Compared to an 8-bit AVR alternative, the PIC16LF84A has a 14-bit instruction word yielding compact code density and shorter firmware paths.
Recommended
Consumer Appliance Control Boards
In washing machines, microwave ovens, coffee makers, and HVAC fan controls, the PIC16LF84AT-04/SS provides 13 GPIO to drive relays, triacs, keypads, and seven-segment displays. Its 35 single-word RISC instructions let a small firmware image handle timing, debounce, and PWM motor control without an RTOS. Hardware CCP and TMR0 deliver PWM and timing precisely enough for closed-loop triac phase-angle firing.
Recommended
Hobbyist and Educational Projects
Arduino and Parallax Basic Stamp community designs frequently migrate to PIC16LF84AT-04/SS for educational microcontroller coursework. The PIC16F84A is one of the most-documented 8-bit MCUs in academic literature, with textbooks dating from the late 1990s and freely available MPLAB IDE toolchains. The 1.75 KB flash supports introductory programming projects (LED blinkers, PWM motor controllers, keypads) while leaving room for in-class exercises in assembly and C.
Recommended
Replacement of Legacy 8051 Designs
Engineers upgrading 1980s/1990s 8051-based products choose PIC16LF84AT-04/SS because of the SSOP-20 footprint flexibility, lower cost, and lower power. The Harvard architecture and single-cycle instruction set typically yield 2-4x throughput improvement at the same clock rate, while the 1.75 KB flash and 68 B RAM fit most small 8051 firmware images. The 35-instruction RISC set also flattens the assembly-language learning curve.
Recommended
Industrial Low-Cost Controllers
Industrial control panels, status indicators, and small actuator drivers use PIC16LF84AT-04/SS because of its wide 2.0-5.5 V supply range, watchdog timer with on-chip RC oscillator, and robust ESD performance. The 13 GPIO accommodates encoder inputs, relay outputs, isolated serial links, and an EEPROM-backed configuration store. The LF silicon makes 24 V industrial rail operation possible with a simple LDO.
Recommended
Smart Card and RFID Tag Controllers
Low-end contactless smart cards and RFID tags integrate PIC16LF84AT-04/SS because the LF silicon handles 2.0-3.0V battery or harvested-RF operation, and the 35 single-word instructions support simple crypto or anti-collision protocols. The 64-byte EEPROM is sufficient for UID, key, and configuration storage. Engineers migrating from older PIC16CXX designs benefit from identical peripheral set and pinout.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF84AT-04/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LF84A-04I/SS | PIC16LF84A-04/SS | PIC16LF84AT-04/SO | PIC16F84A-04I/SS | PIC16F84A-04/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SSOP-20 (0.209 inch) | SSOP-20 - same | SSOP-20 - same | SOIC-20 (0.300 inch) | SSOP-20 - same | SSOP-20 - same |
| Supply Voltage Range | 2.0 V to 5.5 V (LF) | 2.0 V to 5.5 V (LF) | 2.0 V to 5.5 V (LF) | 2.0 V to 5.5 V (LF) | 4.0 V to 5.5 V (F) | 4.0 V to 5.5 V (F) |
| Maximum Clock | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Program Memory | 1.75 KB 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 |
| EEPROM | 64 bytes | 64 bytes | 64 bytes | 64 bytes | 64 bytes | 64 bytes |
| I/O Pins | 13 | 13 | 13 | 13 | 13 | 13 |
| Silicon Revision | LF (pre-A revision) | LF + A revision + ICD | LF + A revision + ICD | LF (pre-A revision) | F + A revision + ICD | F + A revision + ICD |
| Operating Temperature | Commercial (0 to +70 C) | Industrial -40 to +85 C | Commercial 0 to +70 C | Commercial 0 to +70 C | Industrial -40 to +85 C | Commercial 0 to +70 C |
Key Differentiators
- LF silicon supports 2.0 V minimum supply for single-cell battery designs (vs PIC16F84A-04/SS)
- Wide supply range from a single 8-bit MCU die (vs PIC16F84A-04I/SS)
- Internal 4 MHz RC oscillator eliminates external crystal (vs PIC16LF84AT-04/SO (same die, SOIC package))
Design Notes
Estimated: at VDD = 5.0 V, 4 MHz active mode, the PIC16LF84AT-04/SS draws approximately 2 mA typical; sleep current is below 1 uA at 3 V. Place a 100 nF decoupling capacitor within 5 mm of the VDD pin and a 10 uF bulk capacitor near the supply input. The LF silicon allows operation down to 2.0 V, but the internal RC oscillator tolerance is +/- 1% at 4 MHz - calibrate the OSCCAL register for accurate UART timing.
The SSOP-20 (0.65 mm pitch) requires careful PCB layout. Use 0.4 mm wide traces with 0.2 mm spacing; provide ground copper pour under the package for thermal relief and noise immunity. Route the MCLR line away from switching signals to avoid spurious resets. If using the LVP (low-voltage programming) mode, ensure the RB3/PGM pin is not pulled high at power-up, which would lock the part into programming mode.
Avoid exceeding the 5.5 V absolute-maximum VDD - even brief transients from an unregulated supply can damage the part. Do not drive RA4 (open-drain output) as a CMOS push-pull without an external pull-up resistor. When migrating firmware from PIC16F84 (non-A) to PIC16LF84AT-04/SS silicon, verify that any read-modify-write code on PORTB handles the new interrupt-on-change behavior correctly.
The PIC16LF84AT-04/SS has no on-chip ADC; analog signals must be conditioned externally with an op-amp or comparator (e.g., MCP6002) before reaching a digital GPIO. For noisy environments, add a 10 nF ceramic capacitor on each input pin and a ferrite bead on the supply line to suppress conducted EMI. The CCP PWM output can be filtered with a simple RC network (10 kohm + 100 nF) for low-speed DAC emulation.
Compliance Information
RoHS and lead-free per Microchip product page. Not AEC-Q100 qualified - this is a general-purpose MCU not intended for automotive safety-critical applications.
