PIC16C77T-20E/L - 8-Bit 20MHz 14KB OTP MCU | 44-PLCC | Microchip
MPN: PIC16C77T-20E/L ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.65 | $76.50 |
| 100 | $6.8 | $680.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $5.45 | $5,450.00 |
PIC16C77T-20E/L Overview
An OTP microcontroller (One-Time Programmable) is a type of MCU whose program memory can be written exactly once after manufacture using a device programmer, then behaves like mask ROM for the remainder of the part's life. OTP MCUs sit within the broader hierarchy of microcontroller -> embedded controller -> semiconductor, and historically have been used for high-volume cost-sensitive products where firmware is finalized before production. The PIC16C7X family is part of Microchip's mid-range architecture, which adds peripheral integration (ADC, USART, capture/compare/PWM) over baseline PIC16C5X parts while retaining the classic 14-bit instruction set.
Key differentiating features of this part include: an integrated 8-channel 8-bit A/D converter for mixed-signal sensing; a USART module for asynchronous serial communication; two CCP (Capture/Compare/PWM) modules for timing and motor control; an extended operating temperature range suitable for under-hood and industrial environments; and 33 digital I/O lines organized across multiple ports. The RISC-like architecture executes most instructions in a single 200ns cycle at 20MHz (4-clock instruction cycle), providing deterministic interrupt latency. The on-chip watchdog timer, power-on reset, brown-out detect, and code protection features support unattended and field-deployed installations.
Typical application domains for the PIC16C77T-20E/L include automotive body and chassis ECUs, industrial control boards, white-goods motor controllers, HVAC fan and damper actuators, sensor-signal conditioning front ends with ADC, and legacy embedded systems migrating from ceramic-windowed EPROM parts to a cheaper OTP footprint. The wide temperature grade makes it especially appropriate for under-dash instrumentation and engine-bay peripherals.
When designing with this part, place a 0.1uF decoupling capacitor within 5mm of each VDD/VSS pair, route the 20MHz crystal traces symmetrically with short stub lengths, and keep ADC reference traces away from PWM switching nodes. Code-protect the device once firmware is finalized to prevent bit-stream readback. Because OTP memory cannot be updated, provision an external debug header or a flash-equivalent PIC16F77 if in-field firmware updates are required.
This page synthesizes distributor pricing, parametric alternatives, and practical design notes not found in the manufacturer datasheet alone, providing actionable engineering guidance for sourcing, replacement, and EMC-aware PCB layout.
Drop-in alternatives for PIC16C77T-20E/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 PIC16C77T-20E/L (same form factor and footprint) — differing in ADC, Operating Temperature, Package, Program Memory Type, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C77-20E/L
✅ Drop-In✓ In Stock
$9.75 / Unit
View Datasheet →PIC16C77T-20/L
✅ Drop-In✓ In Stock
$9.45 / Unit
View Datasheet →PIC16C77T-10E/L
✓ In Stock
$11.94 / Unit
View Datasheet →PIC16F877-20E/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C77-04E/PT
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$10.45 / Unit
View Datasheet →PIC16C77T-20E/L Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC 16C |
| Core | PIC16C7X mid-range 8-bit RISC |
| Instruction Set Width | 14-bit |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 14 KB (8K x 14) |
| Data RAM | 368 bytes |
| Data EEPROM | Not present on 16C77 |
| Maximum CPU Clock | 20 MHz |
| Instruction Cycle | 200 ns (4 clock cycles per instruction) |
| Supply Voltage (VDD) | 4.0 V to 5.5 V |
| I/O Pins | 33 |
| ADC | 8 channels x 8-bit |
| USART | 1 x |
| CCP Modules | 2 x Capture/Compare/PWM |
| Timers | Timer0, Timer1, Timer2 (3 x 8/16-bit) |
| Watchdog Timer | Yes, on-chip |
| Brown-out Reset | Yes |
| Power-on Reset | Yes |
| Operating Temperature | -40 C to +125 C (Extended, 'E' suffix) |
| Package | 44-pin PLCC (16.59 x 16.59 mm) |
| Mounting Type | Surface Mount (J-Lead) |
PIC16C77T-20E/L Pin Configuration
| Pin 1 | RA2/AN2/VREF- — PORTA bit 2 / Analog input 2 / ADC negative reference |
| Pin 2 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / ADC positive reference |
| Pin 3 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 4 | RA5/AN4/SS — PORTA bit 5 / Analog input 4 / SPI slave select |
| Pin 5 | VSS — Ground reference |
| Pin 6 | OSC1/CLKIN — Crystal oscillator input / external clock in |
| Pin 7 | OSC2/CLKOUT — Crystal oscillator output / clock out (Fosc/4) |
| Pin 8 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 9 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 I/O |
| Pin 10 | RC2/CCP1 — PORTC bit 2 / CCP1 I/O |
| Pin 11 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 12 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 13 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 14 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 15 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 16 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 17 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 18 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 19 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 20 | VSS — Ground reference |
| Pin 21 | VDD — Positive supply (4.0-5.5V) |
| Pin 22 | RB0/INT — PORTB bit 0 / External interrupt input |
| Pin 23 | RB1 — PORTB bit 1 |
| Pin 24 | RB2 — PORTB bit 2 |
| Pin 25 | RB3 — PORTB bit 3 |
| Pin 26 | RB4 — PORTB bit 4 |
| Pin 27 | RB5 — PORTB bit 5 |
| Pin 28 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 29 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 30 | MCLR/VPP — Master clear reset / programming voltage |
| Pin 31 | RE0/RD/AN5 — PORTE bit 0 / Read control for PSP / Analog input 5 |
| Pin 32 | RE1/WR/AN6 — PORTE bit 1 / Write control for PSP / Analog input 6 |
| Pin 33 | RE2/CS/AN7 — PORTE bit 2 / Chip select for PSP / Analog input 7 |
| Pin 34 | VDD — Positive supply (4.0-5.5V) |
| Pin 35 | VSS — Ground reference |
| Pin 36 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 37 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 38 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| Pin 39 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| Pin 40 | VSS — Ground reference |
| Pin 41 | VDD — Positive supply (4.0-5.5V) |
| Pin 42 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 43 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 44 | NC — Not connected (per datasheet PLCC pinout) |
Typical Applications
PIC16C77T-20E/L is suitable for 6 applications: Automotive Body and Chassis ECUs, Industrial Control and PLC I/O Modules, White Goods and Home Appliance Motor Controllers, HVAC Fan and Damper Actuator Nodes, Sensor Signal Conditioning Front Ends, Legacy Embedded Replacement / Bridge Designs.
Automotive Body and Chassis ECUs
The PIC16C77T-20E/L is well suited for automotive body and chassis electronic control units such as lighting controllers, seat controllers, HVAC blend-door actuators, and instrument cluster drivers. Its Extended -40 C to +125 C operating range qualifies it for under-hood and cabin environments where commercial-grade parts would derate or fail, and its 8-channel 8-bit ADC enables direct interface to thermistor, potentiometer, and current-sense circuits without an external ADC chip. The 14KB OTP program memory holds calibrated firmware tables for sensor linearization and actuator PWM profiles, while the two CCP modules drive brushed DC motors and proportional solenoids at up to 20MHz instruction throughput (200ns per instruction). OTP one-time programmability suits high-volume production runs where firmware is locked at the factory.
Recommended
Industrial Control and PLC I/O Modules
In industrial PLC digital and analog input/output modules, the PIC16C77T-20E/L provides 33 digital I/O lines plus 8 ADC channels, allowing a single MCU to scan a 32-point digital input card or a 16-channel analog input card without external multiplexer logic. The 200ns deterministic instruction cycle ensures consistent input debounce and output-update timing, critical for IEC 61131-2 compliant PLC scan cycles. The USART module interfaces to RS-485 transceivers for Modbus RTU backplane communication, while the watchdog timer and brown-out reset guard against supply transients common on factory floors. The Extended temperature grade supports cabinet-free mounting near motors and heaters.
Recommended
White Goods and Home Appliance Motor Controllers
Washing machines, dishwashers, and refrigerator compressors use the PIC16C77T-20E/L as the main control MCU for brushless DC and universal motor speed regulation. The two CCP modules generate complementary PWM at up to 20kHz switching frequency with dead-band insertion, directly driving gate drivers such as the TC4427 or IR2104 for three-phase inverter bridges. The 8-bit ADC reads back motor current via shunt resistors for closed-loop torque control, while the USART links to the user-interface keypad and seven-segment display driver. OTP memory locks the calibrated motor-control firmware at production, eliminating field firmware-update risk.
Recommended
HVAC Fan and Damper Actuator Nodes
Commercial HVAC systems deploy distributed damper and fan actuator nodes that take a 0-10V control signal from a building automation controller and drive a triac-dimmable fan or stepper-driven damper. The PIC16C77T-20E/L reads the analog setpoint on one ADC channel, derives a speed command, and outputs a phase-angle-fired PWM through a CCP module to a MOC3041 opto-isolated triac driver. The Extended -40 C to +125 C grade tolerates rooftop equipment enclosures, while the 14KB OTP holds the linearization curves and PI-control constants for each actuator model. The on-chip USART supports BACnet MS-TP or Modbus backhaul to the central BMS.
Recommended
Sensor Signal Conditioning Front Ends
Multi-sensor data acquisition front ends for weigh scales, gas analyzers, and process instrumentation use the PIC16C77T-20E/L to digitize 4-20mA or 0-5V transducer outputs. The 8-channel 8-bit ADC provides enough resolution for indication-grade displays; the MCU then linearizes via lookup tables stored in the 14KB OTP memory and drives a character LCD or 4-digit seven-segment display through PORTB and PORTC bit-banging. The on-chip USART uploads the conditioned readings to a host PLC or SCADA node. OTP programmability locks the calibration tables per channel at manufacture, eliminating drift from accidental overwrites.
Recommended
Legacy Embedded Replacement / Bridge Designs
The PIC16C77T-20E/L is frequently used as a one-for-one replacement in legacy 1990s-era embedded designs that were originally built around PIC16C74A or PIC16C76 ceramic-windowed EPROM parts. Engineers migrating production to a cheaper OTP footprint keep the same 44-pin PLCC land pattern, same instruction set, and same development toolchain (MPLAB-X with XC8 compiler). When in-field firmware updates are eventually needed, the same PCB layout can host a flash-based PIC16F877-20E/L with no rework, providing a forward migration path. Extended temperature grade supports the original automotive/industrial deployment profile without re-qualification.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C77T-20E/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C77-20E/L | PIC16C77T-20/L | PIC16C77T-10E/L | PIC16F877-20E/L |
|---|---|---|---|---|---|
| Package | 44-PLCC (16.59x16.59 mm) | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 10 MHz (-50%) | 20 MHz |
| Program Memory Type | OTP (14 KB) | OTP (14 KB) | OTP (14 KB) | OTP (14 KB) | Flash (14 KB) |
| Operating Temperature Range | -40 C to +125 C (Extended) | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) | -40 C to +125 C (Extended) |
| ADC Channels x Bits | 8 x 8-bit | 8 x 8-bit | 8 x 8-bit | 8 x 8-bit | 8 x 10-bit |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Data RAM | 368 bytes | 368 bytes | 368 bytes | 368 bytes | 368 bytes |
| In-Field Firmware Update | No (OTP) | No (OTP) | No (OTP) | No (OTP) | Yes (Flash, 100k erase cycles) |
Key Differentiators
- Extended -40 C to +125 C automotive temperature grade (vs PIC16C77T-20/L)
- Flash-reprogrammable equivalent available on same footprint (vs PIC16C77T-20E/L (this part) vs PIC16F877-20E/L)
- 10 MHz lower-cost variant available (vs PIC16C77T-10E/L)
Design Notes
Place a 0.1uF ceramic decoupling capacitor within 5mm of each VDD/VSS pair (pins 21/20, 34/35, 41/40) and a bulk 10uF tantalum or aluminum electrolytic at the board's main 5V entry. The PIC16C77T-20E/L has three VDD/VSS pairs that must all be connected for noise-free ADC and oscillator operation. Tie unused I/O pins to defined logic levels (VDD or VSS) to reduce supply-current transients in sleep mode.
Route the 20MHz crystal traces (OSC1 pin 6, OSC2 pin 7) symmetrically with short stub lengths (<5mm) and keep them at least 3mm away from any switching traces such as PWM outputs on PORTC. Use a ground guard ring around the crystal and load capacitors. For noisy environments use a 4-layer PCB with a continuous ground plane below the PLCC footprint rather than a 2-layer split ground, which can inject oscillator jitter.
Do not attempt to reprogram the OTP memory after programming - OTP parts can be written exactly once. Always verify firmware in a windowed PIC16C77 (PIC16C77/JW) prototype before locking production units. Also note that the MCLR pin (pin 30) must be pulled high through a 10k resistor with a 100nF to VSS for proper reset; leaving MCLR floating causes intermittent brown-out resets. Watchdog timer, brown-out reset, and power-on reset must all be enabled in the configuration word for unattended automotive deployment.
Compliance Information
PIC16C77T-20E/L is an Extended temperature grade part suitable for automotive environments but is not explicitly AEC-Q100 qualified per the available data. RoHS/REACH/lead-free status is not stated in the verified web data and is flagged as unknown pending confirmation from Microchip product ordering information. The 44-pin PLCC package is J-lead surface mount, and PLCC is generally not RoHS-compatible due to tin-lead plating on legacy parts.
