PIC16LC74AT-04I/PT - 8-bit MCU, 7KB OTP, 33 I/O, 4MHz | Microchip
MPN: PIC16LC74AT-04I/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.95 | $8.95 |
| 10 | $7.95 | $79.50 |
| 100 | $6.95 | $695.00 |
| 500 | $5.85 | $2,925.00 |
| 1,000 | $4.95 | $4,950.00 |
PIC16LC74AT-04I/PT Overview
An OTP microcontroller is a type of embedded processor whose program memory can be written exactly once during production programming, not repeatedly rewritten like flash-based MCUs. The PIC16LC74A belongs to Microchip's mid-range PIC16 family, which sits within the broader 8-bit microcontroller category and serves cost-effective deterministic control tasks where simpler processing suffices than 16-bit or 32-bit cores.
Key features include an integrated Analog-to-Digital (A/D) converter, capture/compare/PWM (CCP) modules, multiple timers, and a synchronous/asynchronous serial port. The device uses a Harvard architecture with separate program and data buses, providing deterministic instruction execution suitable for real-time control. The 'LC' suffix indicates the low-voltage CMOS variant optimized for demanding 3.3V to 5V operation with reduced power consumption.
Architecturally, the PIC16LC74AT-04I/PT employs a 14-bit instruction word with 35 instructions, providing a favorable code-density versus MCU capability ratio for embedded control applications. The 'T' suffix indicates tape-and-reel packaging for high-volume assembly, while the 'I' suffix denotes the industrial temperature range of -40C to +85C.
Typical applications include industrial process control, automotive body electronics, sensor signal conditioning, motor control, and consumer white goods. The integrated A/D converter with multiple channels makes the device suitable for analog sensor interfaces in cost-sensitive embedded designs.
When designing with this device, ensure the program memory is correctly allocated before OTP programming since OTP memory cannot be erased. Plan for the industrial temperature range and implement appropriate watchdog reset strategies for reliable operation in electrically harsh industrial environments.
Drop-in alternatives for PIC16LC74AT-04I/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 PIC16LC74AT-04I/PT (same form factor and footprint) — differing in Core Architecture, Package, Operating Temperature Range, ADC, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC74A-04I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
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View Datasheet →PIC16LC74A-04I/PQ
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View Datasheet →PIC16F74-I/PT
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View Datasheet →PIC16F747-I/PT
✅ Drop-In✓ In Stock
$4.4 / Unit
View Datasheet →PIC16LC64AT-04I/PT
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16LC65AT-04I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$7.8 / Unit
View Datasheet →PIC16LC74AT-04I/PT Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Core Architecture | PIC RISC, 14-bit instruction word |
| Program Memory Size | 7 KB (OTP) |
| RAM Size | 192 bytes |
| Number of I/O Pins | 33 |
| Maximum Clock Frequency | 4 MHz |
| Operating Supply Voltage | 3.3 V to 5 V |
| A/D Converter | Yes (integrated, multi-channel) |
| Package | 44-TQFP (PT) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Series | PIC16LC74A |
| Instruction Set | 35 instructions |
| Program Memory Type | OTP (One-Time Programmable) |
| Peripherals | CCP, Timers, USART/SCI, A/D converter |
PIC16LC74AT-04I/PT Pin Configuration
| Pin 1 | OSC1 — Oscillator input |
| Pin 2 | OSC2 — Oscillator output |
| Pin 3 | MCLR — Master clear reset |
| Pin 4 | RA0 — I/O port A bit 0 |
| Pin 5 | RA1 — I/O port A bit 1 |
| Pin 6 | RA2 — I/O port A bit 2 |
| Pin 7 | RA3 — I/O port A bit 3 |
| Pin 8 | RA4 — I/O port A bit 4 |
| Pin 9 | RA5 — I/O port A bit 5 |
| Pin 10 | VSS — Ground |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | RB0 — I/O port B bit 0 |
| Pin 13 | RB1 — I/O port B bit 1 |
| Pin 14 | RB2 — I/O port B bit 2 |
| Pin 15 | RB3 — I/O port B bit 3 |
| Pin 16 | RB4 — I/O port B bit 4 |
| Pin 17 | RB5 — I/O port B bit 5 |
| Pin 18 | RB6 — I/O port B bit 6 |
| Pin 19 | RB7 — I/O port B bit 7 |
| Pin 20 | RC0 — I/O port C bit 0 |
| Pin 21 | RC1 — I/O port C bit 1 |
| Pin 22 | RC2 — I/O port C bit 2 |
| Pin 23 | RC3 — I/O port C bit 3 |
| Pin 24 | RC4 — I/O port C bit 4 |
| Pin 25 | RC5 — I/O port C bit 5 |
| Pin 26 | RC6 — I/O port C bit 6 |
| Pin 27 | RC7 — I/O port C bit 7 |
| Pin 28 | RD0 — I/O port D bit 0 |
| Pin 29 | RD1 — I/O port D bit 1 |
| Pin 30 | RD2 — I/O port D bit 2 |
| Pin 31 | RD3 — I/O port D bit 3 |
| Pin 32 | RD4 — I/O port D bit 4 |
| Pin 33 | RD5 — I/O port D bit 5 |
| Pin 34 | RD6 — I/O port D bit 6 |
| Pin 35 | RD7 — I/O port D bit 7 |
| Pin 36 | RE0 — I/O port E bit 0 |
| Pin 37 | RE1 — I/O port E bit 1 |
| Pin 38 | RE2 — I/O port E bit 2 |
| Pin 39 | VSS — Ground |
| Pin 40 | VDD — Positive supply voltage |
| 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
PIC16LC74AT-04I/PT is suitable for 6 applications: Industrial Process Control, Sensor Signal Conditioning, Motor Control Systems, Consumer White Goods, Automotive Body Electronics, HVAC Control Systems.
Industrial Process Control
The PIC16LC74AT-04I/PT fits industrial process control with its 33 I/O pins, integrated A/D converter, and -40C to +85C industrial temperature range. The 7 KB OTP memory stores control loop firmware, while 192 bytes RAM manages real-time variables. The 3.3V to 5V operating voltage suits both legacy 5V and modern 3.3V industrial systems. Compared to newer 32-bit controllers, the PIC16LC74AT-04I/PT provides deterministic RISC execution at 4 MHz for predictable control loop timing.
Recommended
Sensor Signal Conditioning
The PIC16LC74AT-04I/PT handles sensor signal conditioning with its integrated multi-channel A/D converter reading analog sensors and producing processed outputs. The 33 I/O pins connect various analog and digital sensors simultaneously, while 4 MHz clock provides 1 MIPS for filtering algorithms. OTP memory suits high-volume sensor modules where firmware is fixed at production. The industrial temperature range supports factory floor and outdoor sensor installations.
Recommended
Motor Control Systems
The PIC16LC74AT-04I/PT fits motor control with PWM generation, galvanometer sensors, and GPIO for H-bridge control. The CCP module produces PWM signals for DC motor speed control, while A/D reads current sensing feedback for closed-loop control. Industrial temperature range supports motor drive environments. The 4 MHz clock generates sufficient PWM resolution for typical motor control frequencies up to 20 kHz.
Recommended
Consumer White Goods
The PIC16LC74AT-04I/PT suits consumer white goods like washing machines, dishwashers, and microwave ovens where cost-effective 8-bit control suffices. OTP memory prevents unauthorized firmware copying in high-volume production, while 33 I/O pins interface with displays, keypads, and actuators. The integrated A/D reads temperature and humidity sensors. Industrial temperature range covers appliance operating environments.
Recommended
Automotive Body Electronics
The PIC16LC74AT-04I/PT handles automotive body electronics like seat controllers, mirror adjusters, and interior lighting where non-safety-critical control is acceptable. The 33 I/O pins drive multiple loads while A/D reads position sensors. Industrial temperature range supports cabin environments. However, for safety-critical applications, an AEC-Q100 qualified part is required rather than this industrial-grade device.
Recommended
HVAC Control Systems
The PIC16LC74AT-04I/PT controls HVAC systems with its multi-channel A/D reading temperature sensors and PWM outputs driving fan motors and damper actuators. The 7 KB OTP stores control algorithms for thermostat operation, while 33 I/O pins interface with keypads and displays. Industrial temperature range handles equipment room environments. The deterministic RISC architecture provides predictable response for safety interlocks.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC74AT-04I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC74A-04I/PT | PIC16LC74A-04I/PQ | PIC16F74-I/PT | PIC16F747-I/PT | PIC16LC64AT-04I/PT | PIC16LC65AT-04I/PT |
|---|---|---|---|---|---|---|---|
| Package | 44-TQFP (PT) | 44-TQFP (PT) - same | 44-MQFP (PQ) - close variant | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB Flash | 7 KB Flash | 3.5 KB OTP (-50%) | 7 KB OTP |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz (+400%) | 20 MHz (+400%) | 4 MHz | 4 MHz |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 128 bytes | 192 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 | 33 |
| Operating Voltage | 3.3V to 5V | 3.3V to 5V | 3.3V to 5V | 2V to 5.5V | 2V to 5.5V | 3.3V to 5V | 3.3V to 5V |
| Memory Type | OTP | OTP | OTP | Flash (upgrade) | Flash (upgrade) | OTP | OTP |
Key Differentiators
- OTP memory for production security (vs PIC16F74-I/PT)
- Lower cost for high-volume production (vs PIC16F747-I/PT)
- 44-TQFP package with 33 I/O pins (vs PIC16LC64AT-04I/PT)
Design Notes
OTP (One-Time Programmable) memory cannot be erased after programming. Verify firmware thoroughly using a Flash-equivalent development part (such as PIC16F74-I/PT in the same 44-TQFP package) before committing to OTP production programming. A single bit error in production programming results in a scrapped device.
The 'LC' suffix indicates low-voltage CMOS operation from 3.3V to 5V. Ensure the power supply decoupling network includes a 100nF ceramic capacitor close to each VDD pin (multiple VDD pins exist on the 44-TQFP package). For battery applications, leverage the LC variant's lower quiescent current versus the standard F variant.
The industrial temperature range of -40C to +85C requires verification of oscillator stability across the full temperature range. The 4 MHz clock requires that crystal loading capacitance is correctly matched. For high-temperature operation near 85C, consider derating clock frequency by 10% to ensure timing margins.
Compliance Information
Compliance information not directly stated in the verified web data. The part was published in 1997 per FindIC, predating the historical RoHS directive effective dates. Not suitable for AEC-Q100 automotive applications.