PIC16LF77-I/L - 8-bit 20MHz PIC MCU 14KB Flash 44-PLCC | Microchip
MPN: PIC16LF77-I/L ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.2 | $8.20 |
| 10 | $7.45 | $74.50 |
| 100 | $6.55 | $655.00 |
| 500 | $5.95 | $2,975.00 |
| 1,000 | $5.4 | $5,400.00 |
PIC16LF77-I/L Overview
An 8-bit PIC microcontroller is a Harvard-architecture RISC processor family from Microchip that executes one instruction per clock cycle (except branches), with separate program and data buses that allow simultaneous instruction fetch and data access. Within the broader taxonomy, this device sits in the hierarchy PIC16 -> mid-range PIC -> 8-bit PIC microcontroller -> microcontroller -> embedded processor -> semiconductor. The 'LF' suffix denotes the low-voltage Flash variant that supports operation down to 2.0 V, distinguishing it from the standard PIC16F77 which has a 4.5 V to 5.5 V operating range. The 'I' temperature grade designates the -40 C to +85 C industrial range.
Key differentiating features include the 14 KB Flash program memory (in-system programmable via ICSP), 368-byte data RAM, 256-byte EEPROM data memory, brown-out reset, power-on reset, watchdog timer with its own on-chip RC oscillator, and an 8-bit ADC with 8 input channels. The integrated USART, SSP (SPI/I2C), and two CCP modules significantly reduce external component count. The 33 I/O pins can source/sink up to 25 mA per pin, enabling direct LED drive and interface to power devices without buffering.
The PIC16LF77 uses Microchip's standard mid-range instruction set with 35 single-word/cycle instructions and a 14-bit instruction word. Its deterministic interrupt latency (3 or 4 cycles) and hardware stack (8 levels deep) make it well suited to real-time control loops. The Harvard bus, separate instruction and data paths, and the wide voltage tolerance let the device operate reliably in noisy industrial environments.
Typical applications include industrial control panels, motor control sub-systems, HVAC sensor nodes, automotive body electronics subsystems, smart metering, and embedded operator interfaces with LCDs. The wide voltage tolerance and 33 I/O lines are particularly attractive for legacy industrial designs where the PIC16F877/F777 footprint is already established.
Designers should note that the PLCC-44 socket footprint allows easy prototyping and field replacement, but new designs should consider migrating to PIC16F1xxx or PIC18 families for lower power and more peripherals. A 100 nF decoupling capacitor must be placed within 25 mm of the VDD pins, and an external 4 MHz to 20 MHz crystal or resonator is required for the primary oscillator.
This page synthesizes verified distributor pricing, drop-in PLCC-44 alternatives drawn from Microchip's PIC16 mid-range family, and PCB layout notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16LF77-I/L — 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 PIC16LF77-I/L (same form factor and footprint) — differing in Package, ADC, Operating Temperature, Timers, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F77-I/L
✅ Drop-In✓ In Stock
$7.55 / Unit
View Datasheet →PIC16LF74-I/L
✅ Drop-In✓ In Stock
$4.32 / Unit
View Datasheet →PIC16LF77-I/L Maximum Ratings & Electrical Characteristics
| Core | PIC16 (8-bit Harvard RISC) |
| Program Memory | 14 KB Flash (8K x 14 words) |
| Data RAM | 368 bytes |
| Data EEPROM | 256 bytes |
| Maximum Clock Frequency | 20 MHz |
| Operating Voltage | 2.0 V to 5.5 V |
| Number of I/O Pins | 33 |
| ADC | 8-bit, 8 channels |
| Timers | Timer0, Timer1 (16-bit), Timer2 |
| CCP Modules | 2 (Capture / Compare / PWM) |
| Serial Interfaces | USART / SPI / I2C (SSP) |
| Package | 44-pin PLCC (16.59 x 16.59 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (industrial) |
| Instruction Word Length | 14 bits |
| Instruction Count | 35 single-cycle instructions |
| Hardware Stack | 8 levels |
| I/O Pin Drive | 25 mA source / sink per pin |
| Brown-out Reset | Yes (BOR) |
| Watchdog Timer | Yes (with dedicated RC oscillator) |
| In-System Programming | ICSP (2-wire) |
| RoHS Status | Compliant |
PIC16LF77-I/L Pin Configuration
| Pin 1 | MCLR/VPP — Master clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — Digital I/O / ADC analog input 0 |
| Pin 3 | RA1/AN1 — Digital I/O / ADC analog input 1 |
| Pin 4 | RA2/AN2/VREF- — Digital I/O / ADC input 2 / ADC negative reference |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O / ADC input 3 / ADC positive reference |
| Pin 6 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — Digital I/O / ADC input 4 / SPI slave select |
| Pin 8 | OSC1/CLKI — Oscillator crystal input / external clock input |
| Pin 9 | OSC2/CLKO — Oscillator crystal output / clock output |
| Pin 10 | RC0/T1OSO/T1CKI — Digital I/O / Timer1 oscillator output / Timer1 clock |
| Pin 11 | RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator input / CCP2 PWM output |
| Pin 12 | RC2/CCP1 — Digital I/O / CCP1 PWM output |
| Pin 13 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 15 | RC5/SDO — Digital I/O / SPI data out |
| Pin 16 | RC6/TX/CK — Digital I/O / USART TX / USART clock |
| Pin 17 | RC7/RX/DT — Digital I/O / USART RX / USART data |
| Pin 18 | GND — Ground reference |
| Pin 19 | GND — Ground reference |
| Pin 20 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| Pin 21 | RB0/INT — Digital I/O / external interrupt |
| Pin 22 | RB1 — Digital I/O |
| Pin 23 | RB2 — Digital I/O |
| Pin 24 | RB3/PGM — Digital I/O / ICSP programming clock |
| Pin 25 | RB4 — Digital I/O |
| Pin 26 | RB5/PGM — Digital I/O / ICSP data |
| Pin 27 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 28 | RB7/PGD — Digital I/O / ICSP data |
| Pin 29 | VSS — Ground (logic ground) |
| Pin 30 | RD0/PSP0 — Digital I/O / Parallel Slave Port bit 0 |
| Pin 31 | RD1/PSP1 — Digital I/O / Parallel Slave Port bit 1 |
| Pin 32 | RD2/PSP2 — Digital I/O / Parallel Slave Port bit 2 |
| Pin 33 | RD3/PSP3 — Digital I/O / Parallel Slave Port bit 3 |
| Pin 34 | RD4/PSP4 — Digital I/O / Parallel Slave Port bit 4 |
| Pin 35 | RD5/PSP5 — Digital I/O / Parallel Slave Port bit 5 |
| Pin 36 | RD6/PSP6 — Digital I/O / Parallel Slave Port bit 6 |
| Pin 37 | RD7/PSP7 — Digital I/O / Parallel Slave Port bit 7 |
| Pin 38 | VSS — Ground |
| Pin 39 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| Pin 40 | RE0/RD — Digital I/O / parallel port read control |
| Pin 41 | RE1/WR — Digital I/O / parallel port write control |
| Pin 42 | RE2/CS — Digital I/O / parallel port chip select |
| Pin 43 | AVDD — Analog supply voltage (tied to VDD) |
| Pin 44 | AVSS — Analog ground (tied to VSS) |
Typical Applications
PIC16LF77-I/L is suitable for 6 applications: Industrial Control Panels, HVAC Sensor Nodes, Automotive Body Electronics Subsystems, Smart Metering Edge Nodes, Embedded Operator Interfaces with LCD, Motor Control Sub-Systems.
Industrial Control Panels
The PIC16LF77-I/L fits industrial control panels because its 33 digital I/O pins (each capable of 25 mA source/sink) directly drive indicator LEDs, relay coils, and opto-isolated inputs without external buffers. The wide 2.0 V to 5.5 V supply tolerance simplifies designs that accept both 24 V industrial rails (post-regulation) and battery backup. The 14 KB Flash and 368-byte RAM are adequate for keypad scan, multiplexed 7-segment displays, and Modbus RTU over the integrated USART. The -40 C to +85 C industrial temperature grade is the primary reason this part persists in factory-automation designs.
Recommended
HVAC Sensor Nodes
For HVAC sensor nodes (temperature, humidity, pressure) the PIC16LF77-I/L brings the 8-channel 8-bit ADC and integrated I2C/SPI to a low-cost PLCC package. The 2.0 V to 5.5 V range allows direct operation from a 3.3 V lithium backup during power-line outages, while brown-out reset and watchdog timer keep the node recovering safely from transients on long sensor cables. The 14 KB Flash is sufficient for sensor linearization, hysteresis filtering, and BACnet MS-TP or Modbus framing without external memory.
Recommended
Automotive Body Electronics Subsystems
Although not AEC-Q100 qualified, the PIC16LF77-I/L appears widely in non-safety automotive body subsystems (interior lighting, mirror controllers, seat position memory) where its -40 C to +85 C industrial range, 33 I/O, and integrated CAN-like software UART over its USART simplify node counts. Two CCP modules generate PWM for LED dimming and small DC motor control. PLCC packaging, while legacy, is valued in automotive service environments for socketed replacement. For safety-critical ADAS nodes, designers should select AEC-Q100-qualified dsPIC33 or PIC18 variants.
Recommended
Smart Metering Edge Nodes
The PIC16LF77-I/L's 2.0 V to 5.5 V operating range and 256-byte on-chip EEPROM make it a fit for smart-metering edge nodes that record pulses from electricity, gas, or water meters. The 8-bit ADC with 8 channels can read battery voltage, temperature, tamper switches, and current-sense amplifiers simultaneously. The integrated I2C master reads RTC and EEPROM companion chips while the USART drives the optical or PLC modem. PLCC sockets reduce field-service time in deployments where battery replacement is operator-handled.
Recommended
Embedded Operator Interfaces with LCD
For embedded operator interfaces that integrate a character LCD (16x2 or 20x4) and a 4x4 keypad, the PIC16LF77-I/L offers 33 I/O - enough to drive the LCD in 4-bit mode plus the keypad matrix plus a beeper and status LEDs without multiplexing. The 14 KB Flash holds custom bitmap font tables and message strings in addition to the menu logic. The 8-bit ADC reads a potentiometer for contrast adjustment. Watchdog timer protects against keypad-scan lockups.
Recommended
Motor Control Sub-Systems
Small DC and stepper motor sub-systems (fans, pumps, valves, conveyor segments) are well served by the PIC16LF77-I/L because its two CCP modules can output independent PWM channels - one for motor speed, one for current limiting or braking. The 8-channel ADC monitors back-EMF, current sense, and supply voltage while the USART exposes a Modbus service interface. Industrial temperature range and 25 mA I/O drive eliminate the need for gate-driver buffers in low-current (<1 A) motor circuits.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LF77-I/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F77-I/L | PIC16LF74-I/L | PIC16LF777-I/PT |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin PLCC (16.59 x 16.59 mm) | 44-pin PLCC - same | 44-pin PLCC - same | 44-pin TQFP - NOT pin-compatible with PLCC |
| Operating Voltage | 2.0 V to 5.5 V | 4.5 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| Program Memory | 14 KB Flash | 14 KB Flash | 7 KB Flash | 14 KB Flash |
| Data RAM | 368 bytes | 368 bytes | 192 bytes | 368 bytes |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Number of I/O Pins | 33 | 33 | 33 | 36 |
| ADC | 8-bit, 8 channels | 8-bit, 8 channels | 8-bit, 8 channels | 10-bit, 14 channels |
| EEPROM | 256 bytes | 256 bytes | 128 bytes | 256 bytes |
Key Differentiators
- Wider operating voltage than the PIC16F77-I/L (vs PIC16F77-I/L)
- More memory than PIC16LF74-I/L in the same PLCC-44 footprint (vs PIC16LF74-I/L)
- PLCC-44 package for socketed serviceability (vs PIC16LF777-I/PT)
Design Notes
Place a 100 nF decoupling capacitor within 25 mm of each VDD/AVDD pin (pins 20, 39, and 43) and a 10 uF bulk capacitor on the same supply rail. Connect AVSS (pin 44) directly to the analog ground plane; do not share its trace with switching digital returns. Brown-out reset (BOR) is enabled by config bits; for 3.3 V operation set BOREN=ON with BORV=2.0 V to maximize low-voltage coverage. Estimated: total in-rush current at 20 MHz is approximately 15 mA plus I/O loading.
The PIC16LF77 requires an external 4 MHz to 20 MHz crystal or ceramic resonator on OSC1/OSC2 (pins 8/9) with the correct capacitor load per the crystal datasheet. For low-EMI designs, use a 4-pin SMD crystal with grounded case; for cost-sensitive prototypes a two-pin resonator with internal capacitors is acceptable. If the system clock is supplied externally, drive OSC1 and leave OSC2 unconnected per the Microchip mid-range oscillator note.
The 44-pin PLCC footprint is JEDEC-standard PLCC-44 with 1.27 mm pitch and 16.59 x 16.59 mm body. Keep digital traces more than 5 mm away from the analog ADC inputs (RA0-RA5, RE0-RE2) to minimize crosstalk; route VREF+/VREF- as a Kelvin pair. Place the ICSP test points (RB6/PGC and RB7/PGD) at the board edge so a Microchip PICkit can program the part in-circuit without removing the PLCC socket.
Do not connect any I/O pin directly to voltages above VDD or below VSS - the absolute maximum is VDD + 0.3 V. MCLR (pin 1) requires a 10 kohm pull-up to VDD; failure to do so produces intermittent resets in noisy environments. Watchdog timer must be either enabled in software or explicitly disabled in the config bits - a forgotten WDT can starve the main loop. Estimated: writing to Flash while executing from Flash stalls the CPU for 2-4 ms per row.
Compliance Information
RoHS compliant per Microchip product page. 'I' grade is -40 C to +85 C industrial; not AEC-Q100 qualified - choose AEC-Q100 dsPIC33 or PIC18 for automotive safety. Halogen-free status not published by Microchip for this legacy part.
