PIC16LC74B-04/PQ - 8-bit 4MHz MCU, 7KB OTP, 44-MQFP | Microchip
MPN: PIC16LC74B-04/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.62 | $11.62 |
| 10 | $10.45 | $104.50 |
| 100 | $9.28 | $928.00 |
| 500 | $8.35 | $4,175.00 |
| 1,000 | $7.74 | $7,740.00 |
PIC16LC74B-04/PQ Overview
A microcontroller is a programmable single-chip computer that integrates a CPU, memory, and peripherals; the PIC16CXX mid-range family extends this with EEPROM/OTP program memory and analog peripherals. As the third generation of Microchip's mid-range architecture, the PIC16LC74B sits in a hierarchy of PIC16C63A/65B/73B/74B devices, sharing a fully-static CMOS design that supports low-power and battery-backed operation, a critical advantage in industrial controls and instrumentation where the supply may be unstable.
Key features include 33 digital I/O pins, two 8-bit timers plus one 16-bit timer, a 10-bit multi-channel Analog-to-Digital Converter (ADC), two PWM modules, a Universal Synchronous/Asynchronous Receiver-Transmitter (USART) for serial communication, and a synchronous serial port (SSP) supporting SPI and I2C. The integrated In-Circuit Serial Programming (ICSP) interface enables field firmware updates without removing the part from the board, and the device supports in-circuit debugging. Power-saving features include multiple sleep modes (SLEEP), a watchdog timer with its own on-chip RC oscillator, and programmable brown-out reset.
The architecture combines a Harvard-design CPU with separate program and data buses, allowing instruction fetch and operand read to occur in the same cycle. This dual-bus structure is the source of the family's celebrated code density and deterministic interrupt latency. The 14-bit instruction word keeps loop bodies short, and the 8-level stack plus hardware context save on interrupt entry simplify real-time programming.
Typical applications include industrial control panels, HVAC thermostats, motor-control pre-drivers (with the PWM/CCP modules), sensor signal conditioning (using the ADC), and low-power data-acquisition instruments. The 44-MQFP footprint is well-suited to mid-density designs that need analog inputs and serial connectivity without resorting to larger 64-pin packages.
A critical design consideration is OTP volatility: because OTP memory is programmed once and cannot be erased, prototypes and low-volume production should use the windowed (JW) or flash-based PIC16F74 variant instead. Always specify the correct operating temperature grade for your environment.
This page synthesizes distributor pricing, drop-in same-brand alternatives, and design notes not found on a single manufacturer datasheet page.
Drop-in alternatives for PIC16LC74B-04/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 PIC16LC74B-04/PQ (same form factor and footprint) — differing in Core, Operating Temperature, RoHS Status, Program Memory Size, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC74B-04I/PQ
✅ Drop-In✓ In Stock
$7.6 / Unit
View Datasheet →PIC16LC74BT-04/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC74B-04E/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC65B-04/PQ
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.5 / Unit
View Datasheet →PIC16LC65A-04/PQ
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$6.5 / Unit
View Datasheet →PIC16LC74A-04/PQ
✅ Drop-In✓ In Stock
$2.43 / Unit
View Datasheet →PIC16LC74B-04/PQ Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16CXX mid-range 8-bit RISC |
| Program Memory Type | OTP (One-Time-Programmable) |
| Program Memory Size | 7KB (4K x 14 instructions) |
| RAM Size | 192 bytes |
| EEPROM Data Memory | None (external for non-volatile storage) |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns (5 MIPS peak) |
| Instruction Set Size | 35 single-word instructions |
| Supply Voltage Range (LC) | 2.5 V to 5.5 V |
| Digital I/O Pins | 33 |
| Analog-to-Digital Converter | 10-bit, multi-channel (per Microchip PIC16C74B product page) |
| Timers | Two 8-bit + one 16-bit Timer/Counter modules |
| PWM Modules | 2 (CCP/ECCP) |
| Serial Communication | USART + SSP (SPI / I2C) |
| Operating Temperature | 0 C to +70 C |
| Package | 44-MQFP (10x10 mm), surface-mount tray |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (per distributor listings) |
PIC16LC74B-04/PQ Pin Configuration
| Pin 1 | MCLR/Vpp — Master Clear (active-low reset) / programming voltage input |
| 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 positive |
| Pin 6 | RA4/T0CKI — PORTA bit 4 (open-drain) / Timer0 clock input |
| Pin 7 | RA5/AN4 — PORTA bit 5 / Analog input 4 |
| Pin 8 | OSC2/CLKO — Oscillator output / Clock output (Fosc/4) |
| Pin 9 | OSC1/CLKI — Oscillator input / External clock input |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 PWM output |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM output |
| Pin 13 | RC3/SCK/SCL — PORTC bit 3 / SSP SPI clock / I2C clock |
| Pin 14 | RD0 — PORTD bit 0 (parallel slave port) |
| Pin 15 | RD1 — PORTD bit 1 (parallel slave port) |
| Pin 16 | RD2 — PORTD bit 2 (parallel slave port) |
| Pin 17 | RD3 — PORTD bit 3 (parallel slave port) |
| Pin 18 | RC4/SDI/SDA — PORTC bit 4 / SSP SPI data in / I2C data |
| Pin 19 | RC5/SDO — PORTC bit 5 / SSP SPI data out |
| Pin 20 | RC6/TX/CK — PORTC bit 6 / USART TX / USART sync clock |
| Pin 21 | RC7/RX/DT — PORTC bit 7 / USART RX / USART sync data |
| Pin 22 | RD4 — PORTD bit 4 (parallel slave port) |
| Pin 23 | RD5 — PORTD bit 5 (parallel slave port) |
| Pin 24 | RD6 — PORTD bit 6 (parallel slave port) |
| Pin 25 | RD7 — PORTD bit 7 (parallel slave port) |
| Pin 26 | RE0/RD — PORTE bit 0 / PSP read control |
| Pin 27 | RE1/WR — PORTE bit 1 / PSP write control |
| Pin 28 | RE2/CS — PORTE bit 2 / PSP chip select |
| Pin 29 | VSS — Ground reference |
| Pin 30 | VDD — Positive supply voltage (2.5V to 5.5V) |
| Pin 31 | OSC2 (RB6 alt) — Oscillator / RB6 alternate; per datasheet note |
| Pin 32 | OSC1 (RB7 alt) — Oscillator / RB7 alternate; per datasheet note |
| 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 / LVP programming enable |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock (programming/debugging) |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data (programming/debugging) |
| Pin 41 | AVDD — Analog supply voltage (tie to VDD for best ADC performance) |
| Pin 42 | AVSS — Analog ground reference |
| Pin 43 | VREF- — ADC reference negative (tie to AVSS in single-ended mode) |
| Pin 44 | VREF+/AN5 — ADC reference positive / Analog input 5 (per datasheet note) |
Typical Applications
PIC16LC74B-04/PQ is suitable for 6 applications: Industrial Control Panels, HVAC Thermostats, Sensor Signal Conditioning Nodes, Low-Power Data Acquisition, Motor Control Pre-Driver, Consumer Appliance Control.
Industrial Control Panels
The PIC16LC74B-04/PQ's 33 GPIO, 10-bit ADC and dual PWM modules make it a strong fit for industrial control panels that read sensor inputs and drive relays or H-bridges. Its 2.5V to 5.5V range lets one firmware image run from 3.3V or 5V backplanes; 5 MIPS throughput is more than enough for I/O scanning at 10 ms rates. Place the part in the panel backplane with the watchdog timer enabled to recover from brown-out events.
Recommended
HVAC Thermostats
The PIC16LC74B-04/PQ's low-voltage LC variant (2.5V to 5.5V) and modest 7KB OTP fit HVAC thermostat designs where the MCU reads thermistor inputs and switches triacs. The part's 33 I/O accommodate the LCD segment driver plus 24VAC zero-cross detection and triac gate control. The integrated 10-bit ADC eliminates an external converter, and the 200ns interrupt latency keeps the control loop well below the half-cycle 8.3ms mains period.
Recommended
Sensor Signal Conditioning Nodes
The PIC16LC74B-04/PQ's 10-bit ADC plus USART suits distributed sensor nodes that digitize analog input and stream data via RS-485. The fully-static CMOS core lets the firmware sleep between samples, dropping current to microamp range and stretching battery life. With 192 bytes of RAM the device handles short FIFO buffering before each transmit, and the SSP supports SPI to a local ADC front-end if higher resolution is needed.
Recommended
Low-Power Data Acquisition
The PIC16LC74B-04/PQ's low-voltage supply window and static CMOS design make it well-matched to battery-backed data loggers that sample infrequently and sleep between acquisitions. The integrated 10-bit ADC provides adequate resolution for thermocouple-grade temperature sensing through external amplification, while the 192 bytes of RAM buffer multiple samples before asynchronous serial transmission. Brown-out reset keeps the firmware deterministic during battery droop events.
Recommended
Motor Control Pre-Driver
The PIC16LC74B-04/PQ's two PWM (CCP) channels plus 10-bit ADC are enough for a brushed-DC motor pre-driver that samples current and adjusts duty cycle without an external DSP. The 4MHz instruction rate gives 200ns loop time, well under the 100us typical PWM period at 10kHz switching. Program-memory space accommodates closed-loop control tables without needing an external supervisor.
Recommended
Consumer Appliance Control
The PIC16LC74B-04/PQ's 33 I/O fit mid-density consumer appliances such as coffee machines, washing-machine front panels, and microwave ovens that demand a 5V-tolerant MCU with PWM, ADC and USART in one package. The OTP program memory keeps per-unit production cost down for high-volume SKUs, while the SSP enables driver IC communication via SPI. Use the integrated watchdog timer for field-reliable recovery from power-line glitches.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC74B-04/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC74B-04I/PQ | PIC16LC74BT-04/PQ | PIC16LC74B-04E/PQ | PIC16LC74A-04/PQ | PIC16LC65B-04/PQ | PIC16LC65A-04/PQ |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-MQFP (10x10 mm) | 44-MQFP (10x10 mm) | 44-MQFP (10x10 mm) | 44-MQFP (10x10 mm) | 44-MQFP (10x10 mm) | 44-MQFP (10x10 mm) | 44-MQFP (10x10 mm) |
| Operating Voltage Range | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Program Memory Type | OTP (7KB / 4K x 14) | OTP (7KB / 4K x 14) | OTP (7KB / 4K x 14) | OTP (7KB / 4K x 14) | OTP (7KB / 4K x 14) | OTP (8KB) | OTP (8KB) |
| Operating Temperature | 0 C to +70 C | -40 C to +85 C | 0 C to +70 C (tape-and-reel packaging code) | -40 C to +125 C | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND | NRND | NRND |
Key Differentiators
- Low-voltage LC variant for 3.3V and 5V dual-rail flexibility (vs PIC16C74B-04/PQ)
- Industrial temperature grade option in same package (vs PIC16LC74B-04/PQ (commercial 0C to +70C))
- 8KB upgrade path within the same 44-MQFP footprint (vs PIC16LC65B-04/PQ)
Design Notes
PIC16LC74B-04/PQ's 2.5V to 5.5V single-supply operation lets one board design serve 3.3V and 5V rails, but bulk decoupling must use a 10uF tantalum plus 0.1uF ceramic near each VDD/AVDD pin pair. According to Microchip datasheet 30211D, AVDD and AVSS must be tied to VDD and VSS respectively or the ADC reference saturates; an LC filter on AVDD with -10 dB attenuation at switching frequency is standard practice in motor-control and SSR-noise environments.
PIC16LC74B-04/PQ is OTP-based, so once programmed the firmware is permanent. For prototyping and any low-volume production that may need firmware revisions, use the flash-based PIC16F74-04/PQ (same pinout, same 44-MQFP footprint) instead. The OTP part is the right choice only when firmware is locked and per-unit cost is paramount; allocating time to set up Microchip's MPLAB + PicKit compatible programmer is the main engineering overhead unique to OTP deployment.
Place the 4MHz crystal or resonator within 5mm of the OSC1/OSC2 pins and keep the traces short over a continuous ground pour. RB6/PGC and RB7/PGD are the ICSP pins and must not be used as outputs only; route them to a 5-pin in-system programming header. According to Microchip ICSP specification, avoid long parallel runs on PGC/PGD adjacent to high-current traces, as capacitance above 30pF forces the programmer to drop to slower programming modes.
When the PIC16LC74B-04/PQ drives long cables (RS-485, parallel PSP bus, or external LCD backplanes), add 22-100 ohm series resistors on PORTC outputs to dampen transmission-line overshoot. The PORTD parallel slave port (PSP) outputs and PORTC USART lines are particularly vulnerable to reflection on cables over 100mm. Internal weak pull-ups on PORTB (typical 50kohm) suffice for pushbutton input paths but should not be relied on for wired-OR applications.
Compliance Information
RoHS compliance per distributor (LCSC, Jotrin) listings. REACH and halogen-free status not explicitly published in retrieved web data - flagged unknown. AEC-Q100 not applicable for general-purpose industrial/consumer MCUs.
