PIC16LC774T/PQ - 8-bit MCU, 7KB OTP, 256 RAM, 33 I/O | Microchip
MPN: PIC16LC774T/PQ ✗ End of LifePIC16LC774T/PQ Overview
What is an 8-bit RISC microcontroller? An 8-bit RISC MCU executes a reduced instruction set where most instructions complete in a single clock cycle, giving deterministic timing and high code density for embedded control. The PIC16C/LC family sits at the entry-level of Microchip's mid-range lineup, between the smaller PIC12/PIC14 devices and the higher-pin-count PIC17/PIC18 parts. Its position in the broader semiconductor taxonomy is: microcontroller (MCU) -> 8-bit MCU -> mid-range MCU -> embedded controller -> semiconductor IC. This family is widely used in industrial, consumer, and appliance designs where cost, deterministic interrupt response, and long product life outweigh raw computational throughput.
Key features of the PIC16LC774T/PQ include 35 single-word instructions, four oscillator options including external RC and crystal modes, an internal brown-out reset, a watchdog timer with its own on-chip RC oscillator, in-circuit serial programming (ICSP) capability, and a programmable code protection scheme. The 'LC' suffix denotes the extended low-voltage (2.5 V to 5.5 V) variant, while the 'T' indicates tape-and-reel packaging, and '/PQ' specifies the 44-pin Plastic Quad Flat Pack. Compared with the 5 V-only 'C' parts, the LC variant is preferred for battery-powered or 3.3 V system designs.
Architecturally, the PIC16LC774 uses a Harvard bus layout with separate program and data memory spaces, a 14-bit wide program memory bus, and an 8-bit data bus. The 8-level deep hardware stack and 15 special-function hardware registers underpin its deterministic interrupt handling. Power management is supported via Sleep mode with wake-up on interrupt, and the device is fully static, allowing the clock to be stopped without losing register state.
Typical applications include industrial control panels, HVAC thermostats, instrumentation front-ends, small appliance controllers, security keypads, automotive body electronics (non-safety), and educational or hobby development boards. The 33 I/O pins comfortably drive keypads, character LCDs, and relay or triac interfaces when paired with appropriate buffers.
When designing with this part, allocate the analog and digital I/O banks carefully: pins multiplexed with the A/D converter share a single sample/hold, and placing noisy digital signals adjacent to analog inputs degrades converter noise performance. Always fit decoupling capacitors of 0.1 uF close to VDD/VSS, observe the in-circuit serial programming pinout if the PCB will be programmed in production, and verify that the chosen oscillator mode supports the required instruction cycle timing at the system's lowest operating voltage.
Drop-in alternatives for PIC16LC774T/PQ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
PIC16F877T-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F874T-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F877AT-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F887T-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC774T/PQ Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC16 RISC, Harvard bus |
| Program Memory Size | 7 KB (4K x 14) OTP |
| RAM Size | 256 x 8 bytes |
| Number of I/O Pins | 33 |
| Maximum Clock Frequency | 20 MHz |
| Instruction Throughput | 5 MIPS (DC to 20 MHz) |
| Supply Voltage Range | 2.5 V to 5.5 V (LC low-voltage family) |
| Instruction Set | 35 single-word instructions |
| Oscillator Type | External (RC / Crystal / Resonator selectable) |
| Package / Case | 44-pin MQFP (PQ) |
| Mounting Type | Surface Mount |
| Operating Temperature | 0C to +70C (commercial) |
| Communication Interfaces | USART, SSP/SPI/I2C |
| Watchdog Timer | Yes, with dedicated on-chip RC oscillator |
| Brown-out Reset | Yes, on-chip |
| In-Circuit Serial Programming | Yes (ICSP) |
| Packaging | Tape and Reel (TR) |
| RoHS Status | Compliant |
PIC16LC774T/PQ Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input, active low |
| 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 Vref+ |
| 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 port read / Analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / Parallel slave port write / Analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / Parallel slave port 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 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 / 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 ICSP 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
PIC16LC774T/PQ is suitable for 6 applications: Industrial Control Panels, HVAC Thermostat Controllers, Instrumentation Front-Ends, Small Appliance Controllers, Security Keypad and Access Panels, Educational and Hobby Development Boards.
Industrial Control Panels
The PIC16LC774T/PQ suits industrial control panels where 33 I/O lines can directly drive keypads, character LCDs, optocou-fed relays, and triac interfaces via buffers. Its 20 MHz (5 MIPS) throughput handles keypad scanning, debounce, and protocol parsing in real time. The 7 KB OTP program memory accommodates typical panel firmware including menus and Modbus ASCII, while the extended 2.5-5.5 V LC range tolerates industrial 24 V supply rails after regulation. The on-chip watchdog timer with dedicated RC oscillator detects firmware lock-ups common in electrically noisy environments.
Recommended
HVAC Thermostat Controllers
For HVAC thermostat designs the PIC16LC774T/PQ's on-chip 10-bit-class ADC samples thermistor, humidity, and setpoint potentiometer signals without external converter cost, while the 33 I/O lines drive LCD segments, triac gate drivers, and fan/valve relays. The 2.5-5.5 V LC operation allows direct 3.3 V battery-backed supply, simplifying wall-thermostat power design. Watchdog timer and brown-out reset protect against brown-outs during compressor inrush - critical for field reliability.
Recommended
Instrumentation Front-Ends
Bench and field instrumentation such as digital multimeters and process calibrators benefit from the PIC16LC774T/PQ's deterministic interrupt response and ample 33 I/O for keypad, rotary encoder, and dot-matrix LCD drive. The Harvard architecture and 14-bit-wide program bus deliver predictable execution timing essential for ratiometric measurements and autoranging algorithms. Brown-out reset and watchdog features protect against battery sag in portable instruments.
Recommended
Small Appliance Controllers
Washing machines, microwave ovens, dishwashers, and similar white-goods appliances use the PIC16LC774T/PQ to time motor phases, drive seven-segment displays, and read membrane keypads. The 5 MIPS throughput handles encoder feedback loops for BLDC or universal motor control when paired with an external driver. ICSP enables pre-flash programming at the assembly line while OTP keeps per-unit cost low. The 'LC' voltage range supports single-cell Li-ion or rectified mains-derived 3.3 V rails.
Recommended
Security Keypad and Access Panels
Security keypads, alarm panels, and RFID access controllers use the PIC16LC774T/PQ for matrix keypad scanning, code storage, and tamper detection. The on-chip EEPROM area stores user codes and event logs without an external memory chip. USART communicates with a host controller or GSM module, while the watchdog timer guards against software lock-up during power glitches. Extended 2.5-5.5 V operation tolerates battery-backup transitions in security panels.
Recommended
Educational and Hobby Development Boards
University courses, hobbyist kits, and developer training boards use the PIC16LC774T/PQ to teach 8-bit embedded programming with a generous 33 I/O budget that supports dozens of LEDs, buttons, and peripheral breakout pins. The PIC16 instruction set (35 single-word instructions) is intentionally simple enough for one-week introductory labs, while the 44-pin MQFP package is breadboard-adaptable via carrier PCBs. ICSP allows students to load code from MPLAB X without removing the device.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC774T/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F877T-I/PQ | PIC16F874T-I/PQ | PIC16F877AT-I/PQ | PIC16F887T-I/PQ |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin MQFP (PQ) | 44-pin MQFP (PQ) - same | 44-pin MQFP (PQ) - same | 44-pin MQFP (PQ) - same | 44-pin MQFP (PQ) - same |
| Program Memory | 7 KB OTP | 7 KB FLASH | 4 KB FLASH | 7 KB FLASH (enhanced) | 7 KB FLASH (enhanced) |
| RAM Size | 256 bytes | 256 bytes | 192 bytes | 256 bytes | 368 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 36 |
| Max Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Voltage | 2.5 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| Memory Type | OTP (one-time) | FLASH (reprogrammable) | FLASH (reprogrammable) | FLASH (enhanced) | FLASH (enhanced) |
| Lifecycle Status | NRND | Active | Active | Active | Active |
Key Differentiators
- Reprogrammable FLASH upgrade path on identical pinout (vs PIC16LC774T/PQ (this part) vs PIC16F877T-I/PQ)
- Extended low-voltage 2.5 V to 5.5 V LC operation (vs PIC16LC774T/PQ (LC) vs PIC16C774 (C variant))
- Enhanced successor with larger RAM and more I/O (vs PIC16LC774T/PQ vs PIC16F887T-I/PQ)
Design Notes
Decouple VDD (pins 11 and 32) with a 0.1 uF ceramic capacitor placed within 5 mm of each pin, plus a bulk 10 uF tantalum or aluminum capacitor near the supply entry point. The dual VDD/VSS pin pairs (11/12 and 31/32) mean both supply rails must be decoupled independently to prevent logic errors during high-current digital switching. Tie the MCLR pin (pin 1) to VDD through a 10 kohm resistor and add a reverse-biased diode to VDD if the application requires robust reset behavior during power-down.
Choose the oscillator mode in configuration bits before programming: HS for >4 MHz crystal, XT for 100 kHz-4 MHz, LP for 32 kHz low-power crystals, or RC for cost-sensitive designs. According to Microchip datasheet 30261D, crystal load capacitance values must match the chosen crystal; typical 20 MHz designs use 15-33 pF. For EMI-sensitive applications, keep the crystal traces short and surrounded by a ground guard ring.
Because PIC16LC774T/PQ uses OTP memory, every firmware revision during development requires a new physical part - budget accordingly or use a FLASH PIC16F877T-I/PQ for prototyping. Pin 1 (MCLR) must NOT be left floating - a floating MCLR causes erratic resets from noise. The ADC analog inputs (RA0-RA5, RE0-RE2) share their digital ports; configure them as analog inputs via ADCON1 to disable the digital input buffer and prevent cross-conduction currents that degrade ADC accuracy.
The 44-pin MQFP package has 0.8 mm pin pitch and gull-wing leads that require careful solder paste stencil design. Use a laser-cut stainless steel stencil of 0.1-0.15 mm thickness with apertures slightly smaller than the land pad to prevent solder bridges. Keep analog traces (RA0-RA5, RE0-RE2) physically separated from digital switching traces by at least one trace-width or a ground pour to maintain ADC SNR.
Compliance Information
RoHS and lead-free per Microchip product page; halogen-free status not stated in retrieved data. Not AEC-Q100 qualified - choose PIC16F877T-I/PQ with automotive grade suffix for vehicle applications.
