PIC16C77-04I/P - 8-Bit OTP MCU 14KB 4MHz 40-PDIP | Microchip
MPN: PIC16C77-04I/P ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.2 | $11.20 |
| 10 | $9.95 | $99.50 |
| 100 | $8.4 | $840.00 |
| 500 | $7.1 | $3,550.00 |
| 1,000 | $6.05 | $6,050.00 |
PIC16C77-04I/P Overview
A PIC16C microcontroller is a member of Microchip's PIC (Peripheral Interface Controller) family of RISC-based 8-bit microcontrollers, sitting within the mid-range PIC16 hierarchy. It belongs to the broader category of microcontrollers -> embedded processors -> semiconductor ICs. The '16C' suffix indicates CMOS One-Time Programmable (OTP) EPROM program memory, distinguishing it from the flash-based PIC16F family and the ROM-based PIC16CR family. PIC16C7x parts were among the first mid-range PICs to integrate on-chip ADC, freeing designs from external analog conversion.
Key features include 35 single-word instructions (single-cycle except program branches which take two cycles), 8-level deep hardware stack, 14-bit instruction word, an operating voltage range of 4.0V to 5.5V, and an industrial temperature range of -40C to +85C (denoted by the 'I' suffix). The 40-pin PDIP package is a through-hole form factor suitable for development, prototyping, educational kits, and legacy production systems that require socketed devices for field replacement.
Technical depth: the part uses a Harvard architecture with separate program and data buses, allowing instruction fetch to overlap with data access. The RISC-style instruction set keeps most operations single-cycle, so throughput at 4MHz is approximately 4 MIPS. On-chip peripherals include a USART for serial communication, MSSP (Master Synchronous Serial Port) for SPI/I2C, and 8 channels of 8-bit ADC for sensor interfacing. The industrial-grade temperature range and OTP memory make this part well-suited to medium-volume production where Flash reprogrammability is not required.
Typical applications include industrial control systems, HVAC controllers, motor control front-ends, sensor signal conditioning, embedded instrumentation, and educational/hobbyist microcontroller boards. The on-chip ADC and PWM peripherals suit closed-loop feedback designs such as temperature controllers and small DC motor drivers.
When designing with this part, note that OTP memory cannot be erased or reprogrammed - firmware must be 100% verified before programming. Engineers should consider the newer PIC16F77 (Flash-based) for new designs, or PIC16C77-04/PQ / 04/L variants if a different package is needed while preserving pinout compatibility within the family.
This page synthesizes distributor pricing, same-family drop-in alternatives, and design considerations not found on the manufacturer datasheet front page.
Drop-in alternatives for PIC16C77-04I/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 PIC16C77-04I/P (same form factor and footprint) — differing in Core Architecture, Timers, Package, Operating Temperature, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F77-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C77-04/PT
✅ Drop-In✓ In Stock
$6.08 / Unit
View Datasheet →PIC16C765-I/P
✅ Drop-In✓ In Stock
$5.1 / Unit
View Datasheet →PIC16C74B-04I/P
✅ Drop-In✓ In Stock
$5.55 / Unit
View Datasheet →PIC16C77-04I/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC (8-bit RISC, Harvard) |
| Family | PIC16C7x (mid-range) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 14 KB (8K x 14 words) |
| RAM | 368 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns |
| Supply Voltage | 4.0 V to 5.5 V |
| Number of I/O Pins | 33 |
| ADC | 8 channels, 8-bit |
| Timers | 1 x 8-bit, 1 x 16-bit (via CCP) |
| CCP Modules | 2 |
| Serial Interfaces | USART, MSSP (SPI/I2C) |
| Operating Temperature | -40 C to +85 C (Industrial, 'I' suffix) |
| Package | 40-pin PDIP (Plastic DIP, 0.600 in / 15.24 mm) |
| Pin Count | 40 |
| Mounting Type | Through-Hole (THT) |
| Lead-Free / RoHS | Lead-free per Microchip product page; RoHS compliance varies by date code |
PIC16C77-04I/P Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — Port A bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — Port A bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 — Port A bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF — Port A bit 3 / Analog input channel 3 / VREF+ |
| Pin 6 | RA4/T0CKI — Port A bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — Port A bit 5 / Analog input channel 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — Port E bit 0 / Parallel port read / Analog input channel 5 |
| Pin 9 | RE1/WR/AN6 — Port E bit 1 / Parallel port write / Analog input channel 6 |
| Pin 10 | RE2/CS/AN7 — Port E bit 2 / Parallel port chip select / Analog input channel 7 |
| Pin 11 | VDD — Positive supply voltage (5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Crystal oscillator input / external clock input |
| Pin 14 | OSC2/CLKOUT — Crystal oscillator output / clock output (Fosc/4) |
| Pin 15 | RC0/T1OSO/T1CKI — Port C bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer1 oscillator input / CCP2 module |
| Pin 17 | RC2/CCP1 — Port C bit 2 / CCP1 module (PWM/Capture/Compare) |
| Pin 18 | RC3/SCK/SCL — Port C bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — Port D bit 0 / Parallel Slave Port bit 0 |
| Pin 20 | RD1/PSP1 — Port D bit 1 / Parallel Slave Port bit 1 |
| Pin 21 | RD2/PSP2 — Port D bit 2 / Parallel Slave Port bit 2 |
| Pin 22 | RD3/PSP3 — Port D bit 3 / Parallel Slave Port bit 3 |
| Pin 23 | RC4/SDI/SDA — Port C bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — Port C bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — Port C bit 6 / USART TX / USART clock |
| Pin 26 | RC7/RX/DT — Port C bit 7 / USART RX / USART data |
| Pin 27 | RD4/PSP4 — Port D bit 4 / Parallel Slave Port bit 4 |
| Pin 28 | RD5/PSP5 — Port D bit 5 / Parallel Slave Port bit 5 |
| Pin 29 | RD6/PSP6 — Port D bit 6 / Parallel Slave Port bit 6 |
| Pin 30 | RD7/PSP7 — Port D bit 7 / Parallel Slave Port bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage (5V) |
| Pin 33 | RB0/INT — Port B bit 0 / External interrupt |
| Pin 34 | RB1 — Port B bit 1 |
| Pin 35 | RB2 — Port B bit 2 |
| Pin 36 | RB3/PGM — Port B bit 3 / Low-voltage programming |
| Pin 37 | RB4 — Port B bit 4 |
| Pin 38 | RB5 — Port B bit 5 |
| Pin 39 | RB6/PGC — Port B bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — Port B bit 7 / ICSP data |
Typical Applications
PIC16C77-04I/P is suitable for 6 applications: Industrial Process Control, HVAC Climate Controllers, Small DC Motor and Stepper Control, Educational and Hobbyist Microcontroller Boards, Sensor Signal Conditioning Front-Ends, Legacy Embedded Instrumentation.
Industrial Process Control
The PIC16C77-04I/P fits industrial process control applications because of its 8-channel 8-bit ADC for sensor interfacing (thermistors, pressure transducers, flow meters), 33 digital I/O pins for actuator and relay driving, and USART for SCADA or HMI panel communication. The industrial -40C to +85C temperature range handles factory floor environments. Its 4 MIPS throughput at 4 MHz is adequate for PID loop calculations at 100 Hz sample rates, while the 14KB OTP program memory stores control tables, calibration constants, and state machines. Unlike the flash-based PIC16F77, the OTP memory prevents field tampering of calibration data in safety-critical loops.
Recommended
HVAC Climate Controllers
HVAC controllers benefit from the PIC16C77-04I/P's combination of 8 ADC channels (for temperature, humidity, and pressure sensors), PWM-capable CCP modules (for damper and valve actuator control), and a USART for connection to building management systems via Modbus or BACnet gateways. The 4 MHz clock is more than sufficient for thermostat loop times of 1-10 seconds. The 14KB program memory stores scheduling, setpoint profiles, and fault logging, while the industrial temperature range handles equipment-room environments. The OTP memory ensures firmware stability once deployed.
Recommended
Small DC Motor and Stepper Control
The PIC16C77-04I/P's two CCP modules generate PWM outputs for driving small DC motors, fans, or unipolar stepper motors via simple MOSFET bridges. With 4 MIPS throughput and 33 I/O pins, it can manage H-bridge direction logic, current sensing via the ADC, and quadrature encoder feedback via external interrupt pins. The 8-channel ADC allows multiple motor currents or position sensors to be sampled sequentially. The OTP memory locks in calibration data such as current trip thresholds and acceleration ramps.
Recommended
Educational and Hobbyist Microcontroller Boards
The PIC16C77-04I/P in 40-pin PDIP is ideal for educational microcontroller courses and hobbyist projects due to its through-hole package (easy to breadboard and socket), 40 pins providing ample I/O for learning, and well-documented PIC16 mid-range architecture taught in many university curricula. The 4 MHz ceramic resonator is forgiving for first-time clock bring-up. The 14KB program memory supports substantial student projects while the 35-instruction RISC instruction set is approachable for assembly learners. Students can migrate to PIC16F77 for in-circuit reprogrammability.
Recommended
Sensor Signal Conditioning Front-Ends
Sensor front-end designs use the PIC16C77-04I/P's 8-channel 8-bit ADC for digitizing multiple analog sensors, USART for sending processed data to a host controller or PC, and 33 I/O pins for MUX switching or digital sensor selection. With 4 MIPS, the part can run basic linearization, averaging, and alarm threshold algorithms in firmware. The industrial temperature range suits outdoor sensor installations, while the OTP memory prevents inadvertent firmware modifications in deployed units. PIC16F77-I/P is recommended for new designs needing firmware updates.
Recommended
Legacy Embedded Instrumentation
Maintaining legacy industrial instruments originally designed around PIC16C77-04I/P requires continued supply of this NRND part. The MCU's 33 I/O pins, USART for data output, and 8-channel ADC suit bench-top multimeters, panel meters, and process calibrators from the late 1990s. The OTP memory is acceptable for fixed-function instruments that never required firmware updates. For new instrumentation designs, PIC16F877A-I/P (40-pin PDIP, Flash, more memory) is the recommended Microchip migration path with same pinout and broader peripheral set.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C77-04I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F77-I/P | PIC16C77-04/P | PIC16C765-I/P | PIC16C74B-04I/P |
|---|---|---|---|---|---|
| Package | 40-pin PDIP | 40-pin PDIP (same) | 40-pin PDIP (same) | 40-pin PDIP (same) | 40-pin PDIP (same) |
| Brand | Microchip Technology | Microchip Technology (same) | Microchip Technology (same) | Microchip Technology (same) | Microchip Technology (same) |
| Program Memory | 14 KB OTP | 14 KB Flash | 14 KB OTP | 14 KB OTP | 4 KB OTP |
| Maximum Clock | 4 MHz | 20 MHz | 4 MHz | 4 MHz | 4 MHz |
| RAM | 368 bytes | 368 bytes | 368 bytes | 368 bytes | 192 bytes |
| Memory Type | OTP EPROM | Flash (reprogrammable) | OTP EPROM | OTP EPROM | OTP EPROM |
| Temperature Range | -40C to +85C (Industrial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| ADC Channels | 8 channels, 8-bit | 8 channels, 8-bit | 8 channels, 8-bit | 8 channels, 8-bit | 8 channels, 8-bit |
| Special Features | 33 I/O, USART, MSSP, 2 CCP | Same + Flash reprogrammability | Same peripherals | Same + USB 1.1 SIE, fewer I/O (24) | Same peripherals, less memory |
Key Differentiators
- Industrial temperature range (-40C to +85C) in standard speed grade (vs PIC16C77-04/P)
- Recommended modern replacement is pin-compatible (vs PIC16F77-I/P)
- Higher memory configuration in same package (vs PIC16C74B-04I/P)
Design Notes
OTP memory is one-time programmable - firmware must be 100% verified before programming, as mistakes cannot be erased. For development cycles, prototype with PIC16F77 (Flash) on the same PCB footprint, then move to PIC16C77-04I/P for production. A common pitfall is assuming the BOR (brown-out reset) voltage threshold matches the minimum VDD of 4.0V exactly - in practice it can vary, so design VDD to stay above 4.2V under all load conditions if BOR is enabled. The 'I' suffix denotes industrial -40C to +85C; commercial 'PIC16C77-04/P' without 'I' is 0C to +70C only.
Power supply decoupling requires a 0.1 uF ceramic capacitor placed within 5 mm of each VDD pin (pins 11 and 32 on PDIP-40), plus a bulk 10 uF electrolytic or tantalum on the main VDD rail. According to the PIC16C7X datasheet, VSS pins (12 and 31) should be tied to a low-impedance ground plane. For noise-sensitive ADC applications, an additional LC filter on AVdd (when implemented as separate analog supply) is recommended. Power-on reset (POR) requires VDD rise time below a specified threshold; if the rise is slower, use the MCLR pin with an external RC delay.
The 40-pin PDIP package at 0.600 inch row spacing (15.24 mm) suits through-hole PCB design with 2.54 mm (0.1 inch) pitch. For prototyping, use a 40-pin DIP socket (machined-pin preferred for reliability). When migrating to surface-mount, PIC16C77-04I/PT (TQFP-44) or PIC16C77-04I/L (PLCC-44) are footprint-compatible within the family but require PCB redesign. The crystal oscillator traces (OSC1/OSC2) should be kept short and surrounded by ground; for 4 MHz operation, ceramic resonators with built-in capacitors are a cost-effective alternative to crystals.
Compliance Information
Lead-free and RoHS compliant per Microchip product page. Not AEC-Q100 qualified - for automotive applications consider PIC16F77-E/P or PIC18F variants with automotive qualification. Halogen-free status not explicitly stated in provided data.
