PIC16C77T-04E/PT - 8-Bit 4MHz OTP MCU, 14KB, 44-TQFP | Microchip
MPN: PIC16C77T-04E/PT ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.85 | $14.85 |
| 10 | $13.62 | $136.20 |
| 100 | $12.05 | $1,205.00 |
| 500 | $10.78 | $5,390.00 |
| 1,000 | $9.42 | $9,420.00 |
PIC16C77T-04E/PT Overview
An 8-bit microcontroller (MCU) is a single-chip computer that uses an 8-bit data bus architecture, executes one instruction per cycle on a RISC-style core, and integrates CPU, memory, and peripherals on a single die. PIC16C7X parts belong to the mid-range PIC family — a hierarchy that traces from PIC microcontrollers -> mid-range 8-bit MCUs -> RISC microcontrollers -> embedded processors -> semiconductors. The 'C' suffix denotes the original CMOS OTP lineage, while the 'T-04' speed grade specifies a 4MHz oscillator maximum and 'E' marks the extended temperature variant.
Key features of the PIC16C77T-04E/PT include on-chip peripherals such as a multi-channel 8-bit Analog-to-Digital Converter, two Capture/Compare/PWM modules, a USART serial port, an SSP/SPI/I2C peripheral, Brown-out Reset, Power-on Reset, Power Saving Sleep mode, a Watchdog Timer with its own on-chip RC oscillator, and programmable code protection. The PIC16C77 adds 33 I/O pins (vs 28 on the PIC16C74) and a higher pin count to support expanded parallel-port and analog-channel applications.
Architecturally, the PIC16C77 uses a 14-bit instruction word, a 5-stage pipeline (fetch/decode/read/operate/write), and Harvard bus architecture with separate program and data memories. This RISC design delivers deterministic instruction timing — every instruction executes in one oscillator cycle except branches (two cycles) — simplifying real-time control loops in motor, power-conversion, and instrumentation designs.
Typical applications for this part include industrial process control, motor drive signal conditioning, instrumentation front-ends with on-chip ADC, embedded control with serial networking (USART/SPI), and legacy factory automation upgrades where 5V-tolerant CMOS and 33 I/O are required. Designers also deploy it in test equipment, security panels, and HVAC controllers that need 8-bit deterministic control without an operating system.
A critical design consideration is the OTP memory: code is programmed once and cannot be changed, so firmware must be fully validated before programming. Designers migrating to flash should evaluate the PIC16F877A (drop-in replacement family with flash), but for legacy 5V systems or harsh industrial environments the PIC16C77T-04E/PT remains a robust, time-tested choice.
This page synthesizes distributor pricing, drop-in same-brand alternatives, and practical design notes not consolidated in the Microchip datasheet — including migration guidance from OTP to flash within the same 44-TQFP footprint and side-by-side comparison with the PIC16F877A for engineers modernizing 5V legacy designs.
Drop-in alternatives for PIC16C77T-04E/PT — 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-04E/PT (same form factor and footprint) — differing in Timers, Package, Program Memory Size, Operating Temperature, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C77-04I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C77-04/PT
✅ Drop-In✓ In Stock
$6.08 / Unit
View Datasheet →PIC16C77-10/PT
✅ Drop-In✓ In Stock
$5.7 / Unit
View Datasheet →PIC16C77-10I/P
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC16C67T-20E/PT
✅ Drop-In✓ In Stock
$12.9 / Unit
View Datasheet →PIC16F877A-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F874A-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C77T-04E/PQ
✅ Drop-In✓ In Stock
$11.85 / Unit
View Datasheet →PIC16C77T-04E/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Instruction Word Width | 14-bit |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 14 KB (8K x 14) |
| RAM Size | 368 bytes |
| Data EEPROM | Not present (OTP family) |
| Maximum CPU Frequency | 4 MHz |
| Number of I/O Pins | 33 |
| ADC | 8-bit, multi-channel |
| PWM Modules | 2 (Capture/Compare/PWM) |
| Serial Communication | USART + SSP/SPI/I2C |
| Timers | 3 (Timer0, Timer1, Timer2) |
| Watchdog Timer | Yes (with dedicated on-chip RC oscillator) |
| Brown-out Reset | Yes |
| Power-on Reset | Yes |
| Package | 44-pin TQFP (PT) 10x10 mm |
| Operating Temperature | -40C to +125C (Extended 'E') |
| Mounting Type | Surface Mount |
PIC16C77T-04E/PT Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (Reset) input / Programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF- — PORTA bit 3 / Analog input 3 / ADC reference negative |
| 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 / Parallel port read / Analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / Parallel port write / Analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / Parallel port chip select / Analog input 7 |
| Pin 11 | VDD — Positive power supply |
| Pin 12 | VSS — Ground |
| 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 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 20 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 21 | RC6/TX/CK — PORTC bit 6 / USART async transmit / sync clock |
| Pin 22 | RC7/RX/DT — PORTC bit 7 / USART async receive / sync data |
| Pin 23 | VSS — Ground |
| Pin 24 | VDD — Positive power supply |
| Pin 25 | RB0/INT — PORTB bit 0 / External interrupt |
| Pin 26 | RB1 — PORTB bit 1 |
| Pin 27 | RB2 — PORTB bit 2 |
| Pin 28 | RB3/PGM — PORTB bit 3 / Low-voltage programming |
| Pin 29 | RB4 — PORTB bit 4 |
| Pin 30 | RB5 — PORTB bit 5 |
| Pin 31 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 32 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 33 | VSS — Ground |
| Pin 34 | VDD — Positive power supply |
| Pin 35 | RD0/PSP0 — PORTD bit 0 / Parallel slave port bit 0 |
| Pin 36 | RD1/PSP1 — PORTD bit 1 / Parallel slave port bit 1 |
| Pin 37 | RD2/PSP2 — PORTD bit 2 / Parallel slave port bit 2 |
| Pin 38 | RD3/PSP3 — PORTD bit 3 / Parallel slave port bit 3 |
| Pin 39 | RD4/PSP4 — PORTD bit 4 / Parallel slave port bit 4 |
| Pin 40 | RD5/PSP5 — PORTD bit 5 / Parallel slave port bit 5 |
| Pin 41 | RD6/PSP6 — PORTD bit 6 / Parallel slave port bit 6 |
| Pin 42 | RD7/PSP7 — PORTD bit 7 / Parallel slave port bit 7 |
| Pin 43 | VSS — Ground |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C77T-04E/PT is suitable for 7 applications: Industrial Process Control, Motor Drive Signal Conditioning, Test and Measurement Instrumentation, HVAC Control Systems, Security and Access Control Panels, Embedded Serial Networking (RS-485/RS-232), Legacy 5V Embedded Control Upgrades.
Industrial Process Control
The PIC16C77T-04E/PT fits industrial process control with its 33 digital I/O lines, integrated 8-bit multi-channel ADC, and extended -40C to +125C operating temperature. Its deterministic 1 MIPS throughput at 4MHz handles PID loops, sensor sampling, and actuator control without jitter, while the USART and SSP/SPI/I2C peripherals connect to 4-20mA loop interfaces, RS-485 sensor networks, and EEPROM parameter storage. Brown-out Reset and Watchdog Timer protect against brown-outs and firmware lockups in unattended factory equipment.
Recommended
Motor Drive Signal Conditioning
For motor drive signal conditioning, the PIC16C77T-04E/PT provides two Capture/Compare/PWM modules to generate complementary PWM signals, a multi-channel ADC to sense phase currents and back-EMF, and 33 I/O to interface gate drivers and fault inputs. The PIC RISC core delivers deterministic 1-microsecond instruction timing at 4MHz, ideal for trapezoidal and simple sinusoidal commutation algorithms in low-voltage BLDC and stepper drives up to a few hundred watts.
Recommended
Test and Measurement Instrumentation
The PIC16C77T-04E/PT serves as the controller in bench-top test equipment where deterministic timing and serial connectivity matter. The USART links to PC-side data acquisition, the SPI/I2C peripherals drive LCD displays, DACs, and digital potentiometers, and the 8-bit ADC measures analog inputs at up to [DATA_NEEDED: ADC sample rate]. The 44-TQFP package exposes all 33 I/O for front-panel switches, status LEDs, and isolated RS-485 ports typical in lab instrumentation.
Recommended
HVAC Control Systems
In HVAC controllers, the PIC16C77T-04E/PT reads temperature and humidity sensors via its 8-bit ADC, drives triac outputs through optoisolators with its PWM modules, and communicates with indoor units over UART or SPI. Its extended -40C to +125C temperature grade tolerates rooftop enclosure environments, and Brown-out Reset plus Watchdog Timer survive brown-outs and firmware lockups in unattended installations. The 14KB OTP accommodates zoning logic, scheduling, and fault diagnostics.
Recommended
Security and Access Control Panels
The PIC16C77T-04E/PT is a strong match for security alarm panels where OTP code protection prevents reverse-engineering of proprietary alarm logic. Its 33 I/O scan keypads, reed switches, PIR motion detectors, and sirens; the USART links to central monitoring stations over PSTN or GSM modems; and the Watchdog Timer plus Brown-out Reset ensure reliable operation during power glitches. The -40C to +125C extended grade supports outdoor or unheated enclosure installations.
Recommended
Embedded Serial Networking (RS-485/RS-232)
For multi-drop RS-485 sensor networks and RS-232 point-to-point links, the PIC16C77T-04E/PT's integrated USART handles full-duplex asynchronous serial at standard baud rates, with the SSP supporting SPI master mode for sensor hubs. The 33 I/O connect address-switch inputs, status LEDs, and relay drivers; the 14KB OTP stores Modbus RTU or proprietary protocol stacks; and the extended temperature grade tolerates outdoor cabinet deployment. Engineers often use this part as a low-cost slave node in industrial sensor networks.
Recommended
Legacy 5V Embedded Control Upgrades
Designers maintaining installed equipment designed around the PIC16C77T-04E/PT benefit from its 5V-tolerant CMOS I/O, OTP code protection, and the maturity of the PIC16C7X toolchain (MPLAB XC8, MPASM). The 4MHz speed grade suffices for keypad scanning, LCD driving, and slow control loops. For new 5V designs requiring flash memory, ICD debugging, and field updates, migrate to the PIC16F877A-I/PT which is pin-compatible in the same 44-TQFP footprint and adds 20MHz operation.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C77T-04E/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C77-04I/PT | PIC16C77-04/PT | PIC16F877A-I/PT | PIC16F874A-I/PT | PIC16C77T-04E/PQ |
|---|---|---|---|---|---|---|
| Package | 44-TQFP (PT) 10x10 mm | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-MQFP (PQ) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | OTP (14KB) | OTP (14KB) | OTP (14KB) | Flash (14KB) | Flash (7KB) | OTP (14KB) |
| Maximum CPU Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz | 4 MHz |
| RAM Size | 368 bytes | 368 bytes | 368 bytes | 368 bytes | 192 bytes | 368 bytes |
| Number of I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| ADC | 8-bit, multi-channel | 8-bit, multi-channel | 8-bit, multi-channel | 10-bit, multi-channel | 10-bit, multi-channel | 8-bit, multi-channel |
| Operating Temperature | -40C to +125C (Extended) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) |
| Lifecycle Status | Last-Time-Buy | Last-Time-Buy | Last-Time-Buy | Active | Active | Last-Time-Buy |
Key Differentiators
- Extended -40C to +125C industrial temperature grade (vs PIC16C77-04I/PT)
- Same TQFP-44 footprint as flash-based PIC16F877A-I/PT (vs PIC16F877A-I/PT)
- 4MHz speed grade with PIC16C77 mid-range core (vs PIC16C67T-20E/PT)
Design Notes
Estimated: Vdd decoupling requires a 0.1uF ceramic capacitor placed within 5 mm of each Vdd/Vss pair (pins 11/12, 23/24, 33/34, 43/GND) plus a single 10uF tantalum or ceramic bulk capacitor on the board. The PIC16C7X datasheet recommends separate analog Vdd/Vss routing if the ADC is enabled; place the AVDD feed from the same regulator as Vdd with its own 10uH ferrite + 10uF cap filter to reject digital switching noise from corrupting ADC readings. MCLR (pin 1) must have a 10k pull-up to Vdd; if unused as reset, MCLR can be tied directly to Vdd through a 1k series resistor.
Route the 4 MHz crystal traces (OSC1/OSC2, pins 13/14) as short as possible, keep them away from switching signals, and surround them with a ground guard ring. The 44-TQFP has a center thermal pad; connect it to Vss with multiple vias for thermal dissipation. Place the ICSP programming header (RB6/RB7 = PGC/PGD, MCLR = VPP) on the board edge so firmware can be programmed before final assembly — OTP parts cannot be reprogrammed if a programming fault occurs.
Critical: OTP memory is one-time programmable — a programming failure or logic error in the source code cannot be corrected by re-programming the same part. Always program a fresh part with verified firmware; budget for OTP rejects (typical 1-3% failure rate). Watchdog Timer: enable WDT in configuration bits for unattended designs; the dedicated internal RC oscillator means WDT keeps running even if the main crystal fails. Configuration bits must be set BEFORE code execution begins — verify _CONFIG statements in the source match the target hardware (oscillator mode, watchdog, code protection, brown-out voltage).
The PIC16C77's 8-bit ADC is sensitive to digital switching noise on Vdd. If sampling analog signals below 100 mV, place the PIC in Sleep mode before ADC conversion (the ADC can run from its internal RC) and average 16+ samples for noise rejection. For RS-485 networks, add 120-ohm termination at both ends of the bus and bias resistors (typically 680 ohm pull-up to Vdd on one line, 680 ohm pull-down to GND on the other) to define the idle state. The USART does not include internal biasing — external biasing resistors are mandatory for multi-drop RS-485.
Compliance Information
RoHS/REACH status not confirmed in provided data; Microchip product page should be consulted for the latest declaration. AEC-Q100 not applicable — this is an industrial/consumer MCU, not automotive qualified.