PIC16C77T-04/PT - 8-Bit OTP MCU, 14KB, 4MHz, 44-TQFP | Microchip
MPN: PIC16C77T-04/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.92 | $9.92 |
| 10 | $9.1 | $91.00 |
| 100 | $8.27 | $827.00 |
| 500 | $7.45 | $3,725.00 |
| 1,000 | $6.8 | $6,800.00 |
PIC16C77T-04/PT Overview
An OTP (One-Time Programmable) microcontroller is a variant of programmable logic in which the program memory can be written to exactly once after manufacture, using a special programming procedure. Unlike Flash-based MCUs that can be re-flashed thousands of times, OTP parts are intended for high-volume, cost-sensitive, or security-oriented applications where firmware is finalized during production and field re-programming is undesirable. Within the broader taxonomy, this part belongs to microcontroller -> 8-bit microcontroller -> PIC16 family -> PIC16C7x series -> CMOS EPROM-based MCU -> embedded processing IC.
Key specifications include 33 digital I/O pins, a 14-bit instruction word, an 8-level hardware stack, on-chip peripherals (ADC, USART, CCP, timers), and wide operating voltage support typical of the PIC16C7x family. The -04 suffix denotes the 4 MHz maximum oscillator frequency grade, and the /PT suffix identifies the 44-pin TQFP surface-mount package. The 'T' in the MPN indicates Tape & Reel packaging.
From an architectural standpoint, the PIC16C77T uses Microchip's enhanced mid-range Harvard architecture with separate program and data buses, enabling single-cycle instruction execution (excluding branches). The device integrates brown-out reset, power-on reset, watchdog timer with on-chip RC oscillator, and a 10-bit multi-channel ADC, which collectively reduce external component count in embedded designs.
Typical applications include industrial control systems, automotive body and chassis electronics (legacy), appliance controllers, security panels, sensor signal conditioning front-ends, and any high-volume embedded design where a one-time programmable MCU provides a favorable BOM-to-function ratio. Designers often migrate new designs to the pin-compatible PIC16F877 (Flash) for prototyping and to PIC16C77 (OTP) for production to leverage lower unit cost.
When using this part, note that OTP memory cannot be erased; firmware must be fully validated before programming. A socketed PIC16C77-04/P or PIC16F877-04/P can be used on the development bench and replaced by the production PIC16C77T-04/PT for the final assembly.
This page synthesizes distributor stock levels, pricing tiers, drop-in same-package alternatives drawn from Microchip's PIC16C7x family, and engineering design notes not found in the manufacturer datasheet alone, giving procurement and design engineers a single decision-ready reference.
Drop-in alternatives for PIC16C77T-04/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-04/PT (same form factor and footprint) — differing in Timers, Package, Program Memory Size, Program Memory Type, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C77-04/PT
✅ Drop-In✓ In Stock
$6.08 / Unit
View Datasheet →PIC16C77-04I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C77-10/PT
✅ Drop-In✓ In Stock
$5.7 / Unit
View Datasheet →PIC16C77-20I/PT
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC16C77-04E/PT
✅ Drop-In✓ In Stock
$10.45 / Unit
View Datasheet →PIC16F877-04/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C77T-04/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC, Harvard |
| Program Memory Type | OTP (One-Time Programmable EPROM) |
| Program Memory Size | 14 KB (8K x 14 words) |
| RAM Size | 368 x 8 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Word Width | 14 bits |
| Number of I/O Pins | 33 |
| Package | 44-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| ADC | 10-bit, multi-channel (per family) |
| Communication Peripherals | USART, SSP/SPI/I2C (per PIC16C7x family) |
| Timers | Timer0, Timer1, Timer2 (per family) |
| CCP Modules | 2 (Capture/Compare/PWM) |
| Reset Sources | POR, BOR, WDT (per family) |
| Packaging | Tape & Reel |
PIC16C77T-04/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/VREF- — PORTA bit 2 / analog input 2 / negative reference |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / analog input 3 / positive 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 / parallel slave read / analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / parallel slave write / analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / parallel slave chip select / analog input 7 |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Crystal oscillator input / external clock input |
| Pin 14 | OSC2/CLKOUT — Crystal 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 module |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 module |
| 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 / USART clock |
| Pin 26 | RC7/RX/DT — PORTC bit 7 / USART receive / USART 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 input |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3/PGM — PORTB bit 3 / low-voltage programming input |
| 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 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C77T-04/PT is suitable for 7 applications: Industrial Control Systems, Appliance Control Boards, Security and Alarm Panels, Automotive Body Electronics (Legacy), Sensor Signal Conditioning Front-Ends, Consumer Electronics User Interface Controllers, HVAC Control Modules.
Industrial Control Systems
The PIC16C77T-04/PT fits industrial control applications thanks to its 14KB OTP program memory, 33 I/O lines, and integrated peripherals such as USART, ADC, and PWM. The 4MHz instruction execution provides deterministic timing suitable for sensor sampling, motor speed loops, and simple closed-loop control. The 44-TQFP package enables compact PCB designs while keeping enough I/O to interface with keypads, displays, and relay drivers. OTP memory locks the firmware at production, preventing field tampering in factory-floor installations where firmware stability is more important than field updates.
Recommended
Appliance Control Boards
The PIC16C77T-04/PT is widely deployed in appliance controllers (washing machines, microwave ovens, HVAC indoor units) where its 14KB OTP holds fixed control algorithms, its 33 I/O drive 7-segment displays, keypads, and triac/SCR gates, and its on-chip 10-bit ADC reads thermistor or pressure sensor inputs. The 44-TQFP package supports compact board layouts required behind display panels, while the 4MHz oscillator grade is sufficient for non-realtime-critical user interface and supervisory control loops. OTP memory locks the production firmware to prevent unauthorized modification of safety-critical sequences.
Recommended
Security and Alarm Panels
The PIC16C77T-04/PT is well matched to security panel applications because its 14KB OTP firmware is locked at production and cannot be altered by end users, reducing attack surface for firmware tampering. The 33 I/O drive PIR sensors, reed switches, keypads, sirens, and dialer interfaces. The 10-bit ADC samples backup battery voltage and analog sensor channels, while the USART links to GSM/PSTN dialers. The 44-TQFP package keeps the BOM small enough for cost-sensitive consumer alarm products where a $1-$2 MCU savings at scale matters.
Recommended
Automotive Body Electronics (Legacy)
The PIC16C77T-04/PT is found in legacy automotive body controllers where moderate I/O count and OTP code storage are acceptable. Its 33 I/O drive window lift relays, mirror motors, LED indicators, and switch matrix inputs, while the 10-bit ADC reads battery voltage and current shunts. The 44-TQFP package survives automotive thermal environments within the passenger compartment. For new automotive designs, Microchip recommends migrating to PIC16F877A or dsPIC33 families with AEC-Q100 qualification and CAN/LIN transceivers for modern vehicle networks.
Recommended
Sensor Signal Conditioning Front-Ends
The PIC16C77T-04/PT serves as a sensor conditioning MCU in bridge amplifiers, thermocouple transmitters, and process instrumentation loops. Its 10-bit ADC digitizes conditioned analog signals from load cells, RTDs, or strain gauges, while the USART transmits calibrated data to a host controller or 4-20mA loop. The 33 I/O support HMI buttons and LCD segment displays, and OTP memory locks the calibration coefficients for the lifetime of the sensor module. The 44-TQFP package allows compact sensor housing designs while keeping all I/O accessible.
Recommended
Consumer Electronics User Interface Controllers
The PIC16C77T-04/PT is appropriate for consumer product UI controllers in audio amplifiers, set-top boxes, and kitchen appliances. Its 33 I/O drive IR receivers, capacitive touch keypads, rotary encoders, VFD or LCD displays, and front-panel LEDs. The USART links to the main application processor for command and status exchange. The 14KB OTP memory holds stable production firmware, while the 4MHz clock keeps power consumption low for always-on consumer electronics. The 44-TQFP package supports automated optical inspection (AOI) and standard SMT reflow profiles.
Recommended
HVAC Control Modules
The PIC16C77T-04/PT fits HVAC control modules (fan coil units, thermostat boards, air handler controls) where 33 I/O drive triac outputs for compressor and fan speeds, scan thermistor and humidity sensor inputs via the 10-bit ADC, and present status on character LCDs. OTP memory locks the safety-critical control firmware, while the 44-TQFP package simplifies board layout inside the equipment chassis. The 4MHz clock is sufficient for proportional control loops at HVAC time constants (seconds), and the integrated brown-out reset protects against supply brown-outs during compressor cycling.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C77T-04/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C77-04/PT | PIC16C77-10/PT | PIC16F877-04/PT |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) |
| Program Memory Type | OTP EPROM (14 KB) | OTP EPROM (14 KB) | OTP EPROM (14 KB) | Flash (14 KB) |
| Program Memory Size | 14 KB (8K x 14) | 14 KB (8K x 14) | 14 KB (8K x 14) | 14 KB (8K x 14) |
| RAM Size | 368 bytes | 368 bytes | 368 bytes | 368 bytes |
| Max Clock Frequency | 4 MHz | 4 MHz | 10 MHz | 4 MHz |
| I/O Pins | 33 | 33 | 33 | 33 |
| Reprogrammability | One-Time (OTP) | One-Time (OTP) | One-Time (OTP) | Flash (100K cycles) |
| Lifecycle Status | NRND | NRND | NRND | Active |
Key Differentiators
- Tape & Reel packaging for high-volume SMT assembly (vs PIC16C77-04/PT (tube packaging))
- Re-programmable Flash development path available (vs PIC16F877-04/PT (Flash sibling))
- 4 MHz clock grade appropriate for non-realtime-critical applications (vs PIC16C77-10/PT (10 MHz grade))
Design Notes
OTP memory cannot be erased or rewritten. A firmware bug discovered after programming requires discarding the part and re-programming a fresh unit, which increases rework cost. Always validate the complete firmware image using the Flash-equivalent PIC16F877-04/PT on the development bench before committing to production programming on PIC16C77T-04/PT. Maintain a golden firmware image hash and verify the device ID at production start to catch misprogrammed units.
The 44-TQFP package has a 10x10 mm body with 0.8 mm pitch leads. Follow IPC-7351 land pattern recommendations with pad dimensions of approximately 0.5 mm x 1.5 mm and a 0.4 mm solder mask expansion. Place VDD/VSS bypass capacitors (100 nF ceramic + 10 uF bulk) within 3 mm of the supply pins (11/12 and 31/32) to suppress switching noise. Reserve the MCLR pin (pin 1) with a 10 kohm pull-up to VDD and a 100 nF capacitor to ground for noise-free resets.
Brown-out reset (BOR) is enabled by configuration fuses and should be left enabled for industrial and appliance applications to prevent code execution at low VDD where program memory reads can fail. For battery-backed designs, ensure the supply ramp time meets the datasheet's minimum requirement (typically 0.05 V/ms) to guarantee Power-On Reset (POR) operation. If using the on-chip ADC, decouple VREF (RA3) with a 10 uF tantalum capacitor in parallel with a 100 nF ceramic to stabilize the reference voltage.
Compliance Information
RoHS/lead-free status must be confirmed against the specific Microchip ordering code and date code. Legacy PIC16C7x parts include both lead-free and SnPb finish variants. Not AEC-Q100 qualified; for automotive designs use PIC16F877A-I/PT or dsPIC33 families.