PIC16C77-20E/PQ - 8-bit OTP MCU, 14KB, 20MHz, 44-MQFP | Microchip
MPN: PIC16C77-20E/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.55 | $7.55 |
| 10 | $6.8 | $68.00 |
| 100 | $6.05 | $605.00 |
| 500 | $5.3 | $2,650.00 |
| 1,000 | $4.55 | $4,550.00 |
PIC16C77-20E/PQ Overview
An 8-bit microcontroller (MCU) is a microprocessor integrated with program memory (ROM/OTP/Flash), data memory (RAM), I/O ports, and peripherals on a single die. The PIC16C7X mid-range family sits in Microchip's product hierarchy as: 8-bit MCU -> microcontroller -> embedded processor -> semiconductor. The mid-range architecture uses a 14-bit instruction word and a RISC core delivering 200 ns instruction execution at 20 MHz, balancing code density with deterministic interrupt response. The 8-bit MCU category competes with 16-bit and 32-bit microcontrollers at the cost-sensitive edge of embedded designs where simple I/O control, ADC sampling, and serial communication are dominant workloads.
Key specifications include 33 digital I/O pins, three timer modules, a USART, an SSP supporting both SPI and I2C, and an 8-channel 10-bit (typical mid-range PIC16C7X spec; exact ADC resolution for PIC16C77 is 8-bit per family datasheet ) A/D converter. Wide operating voltage range (2.5V to 6.0V typical) and low standby current (1 uA typical at 3V/32 kHz) enable battery-backed designs. The high sink/source current of 25/25 mA on I/O pins allows direct drive of relays, solenoids, and LEDs without external buffers, reducing BOM cost.
Architecture is built on a Harvard RISC core with separate program and data buses, allowing instruction fetch and operand read in one cycle. The 14-bit instruction word provides single-cycle arithmetic, logical, and bit-manipulation operations. The OTP program memory (14KB) supports in-system programming via the ICSP interface using only two I/O pins, enabling firmware updates without external programming hardware.
Typical applications include industrial automation controllers, automotive body electronics, HVAC control boards, motor control front-ends, smart sensor hubs, and embedded data acquisition systems. Designers choose this device when migrating from legacy 8-bit PIC designs that need extended-temperature operation and on-chip ADC.
Design consideration: the PIC16C77 uses One-Time-Programmable memory, so firmware must be fully validated before programming - no field upgrades are possible. Plan configuration bits, oscillator mode, and watchdog timer early to avoid rework cost.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the Microchip datasheet alone, giving engineers a faster path to sourcing and selection for legacy designs.
Drop-in alternatives for PIC16C77-20E/PQ — 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 PIC16C77-20E/PQ (same form factor and footprint) — differing in Package, Timers, Program Memory Size, Serial Interfaces, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C77-10/PQ
✅ Drop-In✓ In Stock
$4.8 / Unit
View Datasheet →PIC16C77-20/PQ
✅ Drop-In✓ In Stock
$4.78 / Unit
View Datasheet →PIC16C76-20E/SO
✅ Drop-In✓ In Stock
$4.35 / Unit
View Datasheet →PIC16C77-10I/P
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC16C77-04/PQ
✅ Drop-In✓ In Stock
$3.95 / Unit
View Datasheet →PIC16C67-20E/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C77-20E/PQ Maximum Ratings & Electrical Characteristics
| Family | PIC16C7X mid-range |
| Core | 8-bit RISC |
| Instruction Set | 35 single-word instructions |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 14 KB |
| Data RAM | 368 bytes |
| Data EEPROM | Not present (OTP device) |
| Maximum Clock Frequency | 20 MHz |
| Instruction Execution Time | 200 ns at 20 MHz |
| Operating Voltage Range | 2.5 V to 6.0 V (typical) |
| I/O Pins | 33 |
| A/D Converter | 8-bit multi-channel (per PIC16C7X family) |
| Timers | 2 x 8-bit + 1 x 16-bit (CCP) |
| Serial Interfaces | SSP (SPI/I2C) + USART (SCI) |
| I/O Sink/Source Current | 25 mA / 25 mA |
| Standby Current | 1 uA typical @ 3V, 32 kHz |
| Operating Temperature Range | -40C to +125C (Extended, "E" suffix) |
| Package | 44-pin Metric QFP (MQFP/PQ) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC16C77-20E/PQ Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / analog input 3 / ADC reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / read control / analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / write control / analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / chip select / analog input 7 |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator 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 output |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM output |
| 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 transmit / clock |
| Pin 26 | RC7/RX/DT — PORTC bit 7 / USART receive / 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 |
| Pin 33 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3/PGM — PORTB bit 3 / low-voltage programming |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 41 | VDD — Positive supply voltage |
| Pin 42 | VSS — Ground reference |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C77-20E/PQ is suitable for 6 applications: Industrial Automation Controllers, Automotive Body Electronics, HVAC Control Boards, Smart Sensor Hubs, Embedded Data Acquisition Systems, Motor Control Front-Ends.
Industrial Automation Controllers
The PIC16C77-20E/PQ fits industrial automation controller applications because its 14KB OTP program memory holds substantial ladder-logic-equivalent control sequences, while 368 bytes of RAM supports real-time I/O scheduling. Its 33 digital I/O pins with 25 mA sink/source capability directly drive relays, solenoids, and indicator LEDs without external buffer stages, reducing BOM cost. The integrated 8-bit ADC samples analog sensor inputs such as pressure transducers and temperature probes used in process control loops. The Extended temperature grade (-40C to +125C) ensures reliable operation in factory-floor cabinets and outdoor equipment enclosures where ambient temperatures swing widely. Designers also leverage the USART and SSP peripherals to communicate with HMIs, motor drives, and upstream PLCs using Modbus or proprietary protocols.
Recommended
Automotive Body Electronics
The PIC16C77-20E/PQ is well-suited to automotive body electronics modules such as climate control heads, instrument clusters, and lighting controllers because the Extended -40C to +125C temperature range covers under-hood and cabin thermal extremes. Its 25 mA I/O drive strength directly switches incandescent lamps, LEDs, and small relays typical in body-electronics loads, eliminating driver transistors. The PIC mid-range core's deterministic 200 ns instruction cycle supports real-time multiplexing of switch inputs and PWM outputs for dashboard dimming. With 14KB OTP, firmware for seat controllers, mirror adjusters, and accessory modules fits comfortably. Designers must still qualify under AEC-Q100 if their specific automotive OEM mandates it - this MPN is not formally AEC-Q100 qualified.
Recommended
HVAC Control Boards
The PIC16C77-20E/PQ integrates well into HVAC control boards where it must read multiple temperature sensors, switch damper actuators, and drive triac-fired blower motors. The 8-channel 8-bit ADC handles thermistor and analog humidity sensor inputs simultaneously, while the 16-bit CCP timer generates the zero-crossing-triggered triac pulses needed for phase-angle or zero-crossing motor control. The 25 mA source current drives optocoupler LEDs directly for triac isolation. The 20 MHz clock enables 50/60 Hz zero-crossing detection with sub-100 us precision, which is essential for minimizing EMI from phase-controlled loads. Extended temperature operation ensures reliable start-up in unheated attic air-handler units during cold winter conditions.
Recommended
Smart Sensor Hubs
The PIC16C77-20E/PQ serves as a low-cost smart sensor hub that aggregates analog and digital sensor data and forwards it over UART or SPI to a higher-level controller. Its 8-bit ADC provides 8 channels of analog input, sufficient for multi-sensor boards combining thermistors, photocells, and strain gauges. The USART supports RS-232/RS-485 communication with industrial sensor networks, while the SSP peripheral interfaces SPI-based digital sensors such as accelerometers or EEPROM memory. The 1 uA standby current extends battery life in intermittently-sampled remote sensors, and the wide 2.5V to 6.0V operating range accepts varied battery chemistries. The Extended temperature grade supports outdoor environmental monitoring deployments.
Recommended
Embedded Data Acquisition Systems
The PIC16C77-20E/PQ is a natural fit for compact embedded data acquisition front-ends because it combines multi-channel ADC sampling with serial communication in a single 44-pin MQFP device. The 33 I/O pins support chip-select expansion to external ADCs, muxes, or sample-and-hold circuits for higher-channel-count systems. Its 20 MHz clock drives the ADC at conversion rates suitable for low-bandwidth sensor sampling such as temperature, pressure, and flow measurement. The USART streams formatted telemetry to host PCs or PLCs, while the SSP peripheral can drive an SPI LCD for local display. Extended temperature operation supports outdoor or factory-floor DAQ enclosures without active cooling.
Recommended
Motor Control Front-Ends
The PIC16C77-20E/PQ's 16-bit CCP module generates the PWM signals needed for brushed DC motor speed control, while the 8-bit ADC samples motor current via a shunt amplifier for closed-loop torque regulation. The 25 mA I/O drive directly interfaces to optoisolated gate drivers for low-voltage motor bridges, eliminating predriver buffers. The 20 MHz instruction cycle delivers 200 ns loop time, sufficient for kHz-range PWM switching without CPU overload. The Extended temperature grade supports under-hood automotive actuator modules and outdoor pump controllers. Designers can also repurpose the USART for encoder feedback or serial command input from a master controller.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C77-20E/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C77-10/PQ | PIC16C77-20/PQ | PIC16C76-20E/SO | PIC16C77-04/PQ | PIC16C67-20E/PQ |
|---|---|---|---|---|---|---|
| Package | MQFP-44 (PQ) | MQFP-44 (PQ) - same | MQFP-44 (PQ) - same | MQFP-44 (PQ) - same | MQFP-44 (PQ) - same | MQFP-44 (PQ) - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Maximum Clock Frequency | 20 MHz | 10 MHz | 20 MHz | 20 MHz | 4 MHz | 20 MHz |
| Program Memory | 14 KB OTP | 14 KB OTP | 14 KB OTP | 8 KB OTP | 14 KB OTP | 14 KB OTP |
| Data RAM | 368 bytes | 368 bytes | 368 bytes | 368 bytes | 368 bytes | 368 bytes |
| A/D Converter | 8-bit multi-channel | 8-bit multi-channel | 8-bit multi-channel | 8-bit multi-channel | 8-bit multi-channel | None (no ADC) |
| Operating Temperature | -40C to +125C (Extended) | 0C to +70C (Commercial) | 0C to +70C (Commercial) | -40C to +125C (Extended) | 0C to +70C (Commercial) | -40C to +125C (Extended) |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
Key Differentiators
- Extended -40C to +125C temperature range versus commercial-grade same-speed variants (vs PIC16C77-20/PQ)
- 20 MHz instruction rate versus 10 MHz and 4 MHz speed grades (vs PIC16C77-10/PQ and PIC16C77-04/PQ)
- Integrated 8-bit multi-channel ADC versus ADC-less PIC16C67 family (vs PIC16C67-20E/PQ)
Design Notes
The PIC16C77-20E/PQ accepts 2.5V to 6.0V supply voltage per PIC16C7X family datasheet. Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of the VDD pin (pin 11 or pin 32 or pin 41 depending on routing) and add a bulk 10 uF tantalum or aluminum electrolytic capacitor at the board power entry. The PIC mid-range core draws approximately 5 mA at 5V/20 MHz active and 1 uA typical standby at 3V/32 kHz, so power supply design must accommodate both the active transient and the deep-sleep quiescent current. For battery-backed designs, add a series diode or load-share circuit to prevent backfeed into the main supply during sleep.
Place the 20 MHz crystal or resonator within 5 mm of the OSC1 (pin 13) and OSC2 (pin 14) pins to minimize parasitic capacitance and ensure reliable oscillation. Add the recommended load capacitors (typically 15-33 pF for a fundamental-mode crystal) referenced to the analog ground plane. Route the MCLR pin (pin 1) with a 10 kohm pull-up to VDD and a 100 nF decoupling capacitor to ground to allow reliable in-circuit serial programming (ICSP) via the PGC/PGD pins (RB6/RB7). The 44-pin MQFP package has a center thermal pad on the die substrate that should be soldered to a grounded copper pour for thermal dissipation and mechanical strength.
The PIC16C77-20E/PQ uses One-Time-Programmable memory, so firmware bugs cannot be corrected after programming. Validate firmware thoroughly on a PIC16F77 (Flash equivalent in the same 44-MQFP package) before committing code to the OTP device. Configuration bits (oscillator mode, watchdog timer enable, code protection, brown-out reset) must be set correctly during programming - there is no in-system read-back to verify after the fact. Do not exceed 6.0V on VDD - the absolute maximum ratings limit permanent damage to the device. The A/D converter reference voltage on RA3 (pin 5) must be a stable, low-noise source for accurate 8-bit conversions.
Compliance Information
RoHS compliant per Microchip product page. Not formally AEC-Q100 qualified; for automotive designs requiring AEC-Q100, evaluate PIC16F877A or PIC18F family. Halogen-free status not explicitly stated in retrieved web data.
