PIC16F77-I/P - 8-bit 20MHz 14KB FLASH MCU | Microchip | PDIP-40
MPN: PIC16F77-I/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.81 | $12.81 |
| 10 | $11.85 | $118.50 |
| 100 | $10.45 | $1,045.00 |
| 500 | $9.25 | $4,625.00 |
| 1,000 | $8.4 | $8,400.00 |
PIC16F77-I/P Overview
An 8-bit microcontroller is a single-chip computer that processes data 8 bits at a time and integrates a CPU core, program memory, RAM, timers, and peripherals on one die. Within the broader semiconductor taxonomy, an MCU sits under microcontrollers, then embedded processors, then digital ICs. The PIC16F family is Microchip's mid-range 8-bit line using a RISC instruction set with only 35 single-word instructions and 200ns instruction execution at 20MHz, making PIC16F77-I/P a classic general-purpose controller for industrial and embedded designs.
Key features include brown-out detect (BOD), power-on reset (POR), a watchdog timer (WDT) with its own on-chip RC oscillator for reliable operation, and an in-circuit serial programming (ICSP) interface. The 8-bit ADC has 8 input channels multiplexed onto a single sample-and-hold, suitable for sensor reading and process control. The 33 I/O pins drive up to 25mA per pin (sink/source), enabling direct LED and relay driving without buffers.
Architecturally, the PIC16F77 uses a Harvard-style RISC core with separate program and data buses, which gives deterministic single-cycle instruction execution (except branches). The 14-bit wide instruction word allows compact encoding for mid-range PIC instructions. The internal RC oscillator plus optional external crystal up to 20MHz gives designers a flexible clock tree for cost- or accuracy-sensitive designs.
Typical applications include industrial process controllers, sensor interface boards, motor control (small DC/brushless via CCP+PWM), HVAC thermostats, security alarm panels, and legacy equipment retrofits. The wide availability of PIC development tools (MPLAB X, XC8 compiler, PICkit programmers) and the 40-pin PDIP package make this part a drop-in upgrade path from older PIC16C7x OTP devices.
When designing with this part, note that the 'I' suffix denotes the industrial temperature range (-40C to +85C), and the 'P' suffix indicates PDIP packaging. Engineers migrating to modern designs should consider newer PIC16F1xxx or PIC18 families, but the PIC16F77-I/P remains a strong choice for through-hole industrial designs requiring long-life cycle support.
This page synthesizes distributor pricing, drop-in same-package alternatives (PIC16F74, PIC16F76, PIC16F777), and practical design notes not found in a single datasheet view.
Drop-in alternatives for PIC16F77-I/P — 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 PIC16F77-I/P (same form factor and footprint) — differing in Package, Core Architecture, Timers, ADC, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F74-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F777-I/P
✅ Drop-In✓ In Stock
$6.38 / Unit
View Datasheet →PIC16F76-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F727-I/P
✅ Drop-In✓ In Stock
$2.78 / Unit
View Datasheet →PIC16F721-I/P
✅ Drop-In✓ In Stock
$1.12 / Unit
View Datasheet →PIC16F77-I/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16F (8-bit RISC) |
| Program Memory | 14 KB (8K x 14) Flash |
| RAM | 368 bytes |
| Maximum CPU Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns (at 20 MHz) |
| Operating Voltage (Vdd) | 2.0 V to 5.5 V |
| I/O Pins | 33 |
| ADC | 8 channels, 8-bit resolution |
| Timers | 2 x 8-bit + 1 x 16-bit |
| CCP Modules | 2 |
| Serial Interfaces | SSP (SPI/I2C) + USART |
| Brown-out Detect (BOD) | Yes |
| Watchdog Timer (WDT) | Yes (dedicated on-chip RC oscillator) |
| ICSP Programming | Yes (In-Circuit Serial Programming) |
| Package | 40-pin PDIP (DIP-40) |
| Mounting Type | Through-Hole |
| Operating Temperature | -40 C to +85 C (industrial, 'I' suffix) |
PIC16F77-I/P Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / ADC channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / ADC channel 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / ADC channel 2 / ADC negative reference |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / ADC channel 3 / ADC positive reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 (open-drain) / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / ADC channel 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / read control for parallel slave port / ADC channel 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / write control for parallel slave port / ADC channel 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / chip select for parallel slave port / ADC channel 7 |
| Pin 11 | VDD — Positive supply voltage (+2.0V to +5.5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 I/O |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 I/O |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 20 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 21 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 22 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 23 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — PORTC bit 6 / USART async transmit / USART sync clock |
| Pin 26 | RC7/RX/DT — PORTC bit 7 / USART async receive / USART sync data |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 28 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 29 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| Pin 30 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage (+2.0V to +5.5V) |
| Pin 33 | RB0/INT — PORTB bit 0 / external interrupt input |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3/PGM — PORTB bit 3 / LVP programming enable |
| Pin 37 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 38 | RB5 — PORTB bit 5 (interrupt-on-change) |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data |
Typical Applications
PIC16F77-I/P is suitable for 7 applications: Industrial Process Controller, HVAC Thermostat Board, Security / Alarm Panel, Sensor Interface / Data Acquisition Board, Small Motor Control (CCP/PWM), Legacy Retrofit / Industrial Replacement, Educational / Development Board MCU.
Industrial Process Controller
The PIC16F77-I/P suits industrial process controllers because of its 8-channel 8-bit ADC for reading analog sensor inputs (temperature, pressure, flow) plus 33 I/O pins for driving relays, contactors, and indicator LEDs without buffers. The 14 KB Flash holds typical PID-loop firmware, and the two CCP modules generate PWM outputs for proportional valves or motor-speed commands. Its 2.0-5.5 V supply range and industrial -40 C to +85 C temperature grade tolerate harsh factory-floor environments. Brown-out detect and watchdog timer add the fault-recovery robustness required for unattended control panels.
Recommended
HVAC Thermostat Board
HVAC thermostat designs use the PIC16F77-I/P for its low cost, 20 MHz compute headroom for hysteresis-based temperature control, and integrated ADC for thermistor or analog sensor readout. The USART provides a service-port interface to handheld installers, while the SSP can drive a small SPI LCD for room-temperature display. With 368 bytes of RAM the controller easily maintains setpoint, hysteresis, and scheduling state. Industrial temperature grade plus 25 mA I/O drive enables direct triac interface through opto-isolators for heater control.
Recommended
Security / Alarm Panel
The PIC16F77-I/P is well-suited to security alarm panels where multiple zone inputs (PIR, door contacts, glass-break detectors) are monitored via digital I/O and analog inputs through the 8-channel ADC. The 33 I/O pins map cleanly to 8-16 zone inputs plus keypad scanning, siren driver, and communicator interface. Flash ICSP programming enables factory pre-programming and field firmware updates. Brown-out detect and watchdog timer guarantee the panel recovers from power-line transients - a regulatory requirement for UL-listed alarm systems.
Recommended
Sensor Interface / Data Acquisition Board
For sensor interface and data acquisition boards, the PIC16F77-I/P's 8-channel ADC samples multiple analog inputs and forwards results over the USART or SPI to a host processor. The 20 MHz CPU enables ~100 kSPS aggregate throughput from the ADC with averaging. Industrial -40 C to +85 C operation permits deployment in outdoor and factory environments, while the 14 KB Flash accommodates calibration tables and linearization routines. ICSP programming permits in-system firmware updates during board bring-up and field service.
Recommended
Small Motor Control (CCP/PWM)
The PIC16F77-I/P drives small DC motors, fans, or low-power brushless motors through its two CCP/PWM modules and 16-bit timer. With 20 MHz CPU clock the PWM frequency can be set above the audible band (>20 kHz) for silent operation. The 33 I/O pins accommodate direction-control logic, Hall-sensor feedback inputs, and tachometer capture via the CCP capture mode. Industrial temperature grade and brown-out detect suit motor-control boards in white goods and light-industrial equipment where reliability matters.
Recommended
Legacy Retrofit / Industrial Replacement
The PIC16F77-I/P is the canonical replacement for older PIC16C73/74/76/77 OTP and ROM-based PICs in legacy industrial equipment. Its 40-pin PDIP pinout matches the original footprint exactly, allowing drop-in installation into existing boards with no PCB rework. 14 KB Flash accommodates modernized firmware while preserving the legacy peripheral set (USART, SSP, ADC). Active production status and continued Microchip distributor stock mean industrial users can extend the service life of installed equipment without redesigning the controller board.
Recommended
Educational / Development Board MCU
The PIC16F77-I/P is a popular choice for embedded systems training and PIC development boards because of its 40-pin PDIP through-hole footprint (easy to prototype on breadboards), rich peripheral set (ADC, timers, USART, SPI, I2C), and broad documentation. MPLAB X IDE and the XC8 compiler are free, while PICkit programmers support ICSP for in-circuit debugging. 14 KB Flash holds complete student projects including state machines, small protocol stacks, and sensor interfaces. The DIP package makes it ideal for instructional labs where chips may be inserted and removed many times.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F77-I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F74-I/P | PIC16F777-I/P | PIC16F76-I/P | PIC16F727-I/P | PIC16F721-I/P |
|---|---|---|---|---|---|---|
| Package | PDIP-40 (DIP-40) | PDIP-40 (DIP-40) - same | PDIP-40 (DIP-40) - same | PDIP-40 (DIP-40) - same | PDIP-40 (DIP-40) - same | PDIP-40 (DIP-40) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 14 KB | 7 KB | 14 KB | 14 KB | 14 KB | 7 KB |
| RAM | 368 bytes | 192 bytes | 368 bytes | 368 bytes | 368 bytes | 256 bytes |
| ADC | 8 ch, 8-bit | 5 ch, 8-bit | 14 ch, 10-bit | 5 ch, 8-bit | 14 ch, 8-bit | 12 ch, 8-bit |
| I/O Pins | 33 | 33 | 36 | 22 | 36 | 36 |
| Max CPU Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Voltage | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| Param Match (drop-in proximity) | 100% (reference) | 90% (less Flash/RAM/ADC) | 100% (drop-in successor) | 80% (fewer I/O) | 90% (newer gen) | 80% (less Flash/RAM) |
Key Differentiators
- 40-pin PDIP with 33 I/O pins, larger than PIC16F76's 22 I/O (vs PIC16F76-I/P)
- Functional drop-in successor with 10-bit ADC and NanoWatt (vs PIC16F777-I/P)
- Larger Flash and RAM than PIC16F74 (vs PIC16F74-I/P)
Design Notes
Estimated: at 20 MHz and 5 V supply, the PIC16F77-I/P typically draws 15-25 mA active, depending on which peripherals are enabled. Place a 100 nF decoupling capacitor as close as possible to pins 11 and 32 (the two Vdd/Vss pairs) using short, wide traces. For battery-backed designs, switch to the lower-power PIC16F777 or PIC16F1xxx variants; the original PIC16F77 does not have NanoWatt technology and its idle current is much higher.
Keep the 20 MHz crystal or resonator traces (OSC1/OSC2, pins 13-14) under 10 mm and isolated from high-current switching traces. Connect MCLR (pin 1) through a 10 kohm pull-up to Vdd, and add the MCLR decoupling capacitor (typically 100 nF to 1 uF) right at the pin. For ICSP programming access, dedicate a 6-pin header on RB6 (PGC), RB7 (PGD), MCLR, Vdd, Vss, and leave RB3/PGM accessible for low-voltage programming mode.
Do not leave the OSC pins floating when using the internal RC oscillator mode; the datasheet requires a defined configuration on OSC1 even in RC mode to prevent erratic behavior during power-up. Avoid using the PIC16F77 in new designs if firmware is expected to grow beyond 14 KB - the PIC16F777 or PIC16F1xxx family offers more headroom and is pin-compatible. Never apply VPP (programming voltage, ~13V) to MCLR during normal operation; use the standard external reset circuit (10k + cap) instead.
The PIC16F77's parallel slave port (PORTD, pins 19-22 and 27-30) operates at 5V TTL levels and should be buffered when interfaced with 3.3V peripherals. Use the built-in USART (RC6/RC7) for noisy industrial environments rather than bit-banged UART - the hardware USART handles framing and noise filtering. For SPI buses running above 5 MHz, add 33 ohm series resistors at the SCK/SDO/SDI pins to dampen ringing on the bus.
Compliance Information
RoHS and REACH compliance per Microchip product page. Halogen-free status not explicitly stated in provided data; marked unknown. AEC-Q100 not applicable for general-purpose MCU; PIC16F77-I/P targets industrial applications not automotive.
