PIC16LC74AT-04/PT - 8-Bit PIC MCU 7KB OTP 4MHz TQFP-44 | Microchip
MPN: PIC16LC74AT-04/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.65 | $76.50 |
| 100 | $6.82 | $682.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $5.55 | $5,550.00 |
PIC16LC74AT-04/PT Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, non-volatile program memory, and peripherals. The PIC16C7X family implements a RISC architecture with 35 single-cycle instructions, providing deterministic throughput and simplified C-language development. The integrated 8-channel, 8-bit A/D converter, synchronous serial port (SSP) for SPI/I2C, USART, and capture/compare/PWM modules make it a complete mixed-signal control solution. This places the PIC16LC74AT-04/PT in the wider hierarchy of MCU -> 8-bit MCU -> mid-range MCU -> microcontroller -> embedded controller -> semiconductor.
Key features of this part include: a wide operating voltage range that supports both 3.3V and 5V rails, on-chip Power-on Reset and Power-up Timer, Watchdog Timer with its own on-chip RC oscillator for reliable operation, and an operating temperature range of 0C to +70C (commercial). The 4 MHz oscillator with 1:1 instruction-to-oscillator ratio produces 1 MIPS throughput, adequate for cost-sensitive control loops. Brown-out Reset circuitry and code protection protect field-deployed firmware. The 33 I/O pins support direct interfacing of keys, LEDs, LCDs, sensors and actuators without external glue logic.
Architecturally, the device uses Harvard memory architecture with separate program and data buses, allowing instruction fetch and operand access in a single clock cycle. The OTP program memory is factory- or development-tool-programmable and is well-suited to low- to medium-volume production. The integrated peripherals are configured through Special Function Registers mapped into the data memory space, and interrupts are vectored with on-chip hardware context save.
Typical applications include industrial process control, appliance control (washing machines, microwave ovens, HVAC), security and alarm systems, automotive body electronics, and battery chargers. The integrated A/D and PWM simplify motor control loops, while the USART enables networked sensor and metering applications.
When designing with the PIC16LC74AT-04/PT, ensure the ICSP clock and data lines are accessible for in-circuit programming and debugging. Use a 100 nF decoupling capacitor close to each VDD pin and a bulk capacitor at the regulator output. Note that this OTP variant is intended for development and low-volume production; for higher volumes, a mask-ROM or Flash equivalent (such as the PIC16F74) is recommended.
This page synthesizes distributor pricing, package-compatible drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16LC74AT-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 PIC16LC74AT-04/PT (same form factor and footprint) — differing in Program Memory Size, Program Memory Type, RAM Size, Package, A/D Converter.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F74-I/PT
✅ Drop-In✓ In Stock
$5.55 / Unit
View Datasheet →PIC16F747-I/PT
✅ Drop-In✓ In Stock
$4.4 / Unit
View Datasheet →PIC16LC74A-04/PQ
✅ Drop-In✓ In Stock
$2.43 / Unit
View Datasheet →PIC16LC65AT-04I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$7.8 / Unit
View Datasheet →PIC16LC67-04/PT
✅ Drop-In✓ In Stock
$6.98 / Unit
View Datasheet →PIC16LC74AT-04/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 mid-range 8-bit RISC |
| Instruction Set | 35 single-cycle instructions |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 bytes |
| EEPROM Data Memory | None |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns |
| MIPS (Peak) | 1 MIPS |
| Supply Voltage | 3.0 V to 6.0 V (3.3V/5V nominal) |
| I/O Pins | 33 |
| A/D Converter | 8 channels, 8-bit resolution |
| Timers | Timer0, Timer1, Timer2 |
| Capture/Compare/PWM | Yes (CCP module) |
| Serial Interfaces | USART, SSP (SPI / I2C) |
| Operating Temperature | 0 C to +70 C (commercial) |
| Package | 44-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
PIC16LC74AT-04/PT Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 2 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 3 | RA2/AN2 — PORTA bit 2 / Analog input channel 2 |
| Pin 4 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / VREF+ |
| Pin 5 | RA4/AN4/T0CKI — PORTA bit 4 / Analog input 4 / Timer0 clock |
| Pin 6 | RA5/AN5/SS — PORTA bit 5 / Analog input 5 / SPI slave select |
| Pin 7 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 8 | OSC1/CLKIN — Oscillator input / external clock in |
| Pin 9 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / clock |
| Pin 10 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 11 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Pin 12 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 13 | RD0 — PORTD bit 0 |
| Pin 14 | RD1 — PORTD bit 1 |
| Pin 15 | RD2 — PORTD bit 2 |
| Pin 16 | RD3 — PORTD bit 3 |
| Pin 17 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 18 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 19 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 20 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 21 | RD4 — PORTD bit 4 |
| Pin 22 | RD5 — PORTD bit 5 |
| Pin 23 | RD6 — PORTD bit 6 |
| Pin 24 | RD7 — PORTD bit 7 |
| Pin 25 | VSS — Ground reference |
| Pin 26 | VDD — Positive supply (3.3V or 5V) |
| Pin 27 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 28 | RB1 — PORTB bit 1 |
| Pin 29 | RB2 — PORTB bit 2 |
| Pin 30 | RB3/PGM — PORTB bit 3 / LVP program |
| Pin 31 | RB4 — PORTB bit 4 |
| Pin 32 | RB5 — PORTB bit 5 |
| Pin 33 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 34 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 35 | RE0/RD — PORTE bit 0 / parallel port read |
| Pin 36 | RE1/WR — PORTE bit 1 / parallel port write |
| Pin 37 | RE2/CS — PORTE bit 2 / parallel port chip select |
| Pin 38 | VDD — Positive supply (3.3V or 5V) |
| Pin 39 | VSS — Ground reference |
| Pin 40 | RA6 — PORTA bit 6 |
| Pin 41 | RA7 — PORTA bit 7 |
| Pin 42 | VDD — Positive supply (3.3V or 5V) |
| Pin 43 | VSS — Ground reference |
| Pin 44 | MCLR/VPP — Master clear reset / programming voltage |
Typical Applications
PIC16LC74AT-04/PT is suitable for 6 applications: Industrial Process Control, Appliance Control (HVAC, Washers, Microwave Ovens), Security and Alarm Systems, Battery Chargers and Power Management, Automotive Body Electronics (Non-Safety), Sensor Signal Conditioning and Display Driving.
Industrial Process Control
The PIC16LC74AT-04/PT is well-suited to industrial process controllers where its integrated 8-channel 8-bit A/D converter, PWM module, and USART are leveraged for closed-loop control of temperature, pressure, and flow. The 7 KB OTP program memory holds modest control algorithms and Modbus-style protocols, while the 33 digital I/O pins drive relays, triacs, and indicator LEDs directly. Operating from a 3.3V or 5V rail makes it compatible with both legacy 5V logic and modern 3.3V sensor ASICs. The commercial 0-70 C operating range covers factory-floor equipment enclosures. Compared to a discrete analog control loop, this MCU reduces BOM count by integrating ADC, timers, and serial interface in one 44-pin TQFP device.
Recommended
Appliance Control (HVAC, Washers, Microwave Ovens)
In appliance control boards the PIC16LC74AT-04/PT serves as the main state machine, sequencing wash cycles, microwave cooking profiles, or HVAC compressor stages. Its 4 MHz instruction rate and 1 MIPS throughput are sufficient for time-based control of relays, triacs, and seven-segment displays, while the PWM module modulates fan motor speed or heater elements. The 33 I/O pins directly drive LED indicators and read keypads without external decoding logic. The 7 KB OTP holds fixed-mode firmware safely in production. Compared with discrete logic controllers, the MCU reduces part count dramatically while adding flexibility for firmware-revision customization. Operating from 3.0-6.0V supports both rectifier-capacitor 5V rails and modern switch-mode 3.3V supplies.
Recommended
Security and Alarm Systems
The PIC16LC74AT-04/PT is widely deployed in security alarm panels because its 33 I/O pins read multiple PIR detectors, door/window reed switches, and glass-break sensors, while the integrated A/D and USART monitor backup battery voltage and report to a central station via dial-up or serial modem. The 192-byte RAM holds sensor debounce state and event log buffers, and the 7 KB OTP stores the fixed alarm logic and dialer tone sequences. The LC variant's wide 3.0-6.0V supply range is tolerant of weakly-regulated battery-backed rails. Brown-out Reset reliably detects power failures, and the Watchdog Timer recovers the panel from software lockups. This single-chip solution replaces multiple 555 timers and glue logic in legacy alarm designs.
Recommended
Battery Chargers and Power Management
The PIC16LC74AT-04/PT's 8-bit ADC monitors battery voltage and charge current, while its PWM output drives a switching FET or linear regulator for closed-loop charge control of NiCd, NiMH, and lead-acid battery packs. The 33 I/O pins handle cell-balancing FETs, temperature sensors, status LEDs, and SMBus-style chargers. The LC variant's 3.0-6.0V supply range is directly compatible with single-cell Li-ion and 6V lead-acid battery stacks. The 4 MHz clock rate is sufficient for state-machine charge algorithms and accurate time-based termination. Compared to dedicated charger ASICs, the programmable MCU supports multi-chemistry support and field updates of charge profiles without hardware rework.
Recommended
Automotive Body Electronics (Non-Safety)
For non-safety automotive body electronics such as lighting controllers, seat-position memory, and HVAC blend-door actuators, the PIC16LC74AT-04/PT operates from the vehicle's 12V bus regulated to 5V, reading switches and position sensors via its 8-channel ADC and driving motors via PWM. The commercial 0-70 C range covers most cabin locations. Designers should note that AEC-Q100 Grade 0 qualified parts like PIC16F74-I/PT are preferred for under-hood environments. The 33 I/O pins multiplex numerous switch inputs and PWM outputs without external logic. Compared to relay-logic body controllers, this MCU enables software-driven features such as one-touch windows, programmable welcome lighting, and remote keyless entry integration via the USART.
Recommended
Sensor Signal Conditioning and Display Driving
The PIC16LC74AT-04/PT's integrated 8-bit ADC and 33 I/O pins make it a flexible signal-conditioning front end for multi-sensor instruments such as weather stations, data loggers, and laboratory meters. The USART streams readings to a host PC or LCD display controller, while the PWM module drives backlight brightness proportional to ambient light. The 7 KB OTP holds calibration tables and lookup curves for thermocouple linearization, humidity compensation, and strain-gauge bridge balancing. Operating from 3.3V supports low-power sensor systems with battery or USB power. Compared to analog-only instrumentation, the programmable MCU adds linearity correction, range switching, and digital readouts with a single 44-pin TQFP device.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC74AT-04/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F74-I/PT | PIC16F747-I/PT | PIC16LC74A-04/PQ | PIC16LC65AT-04I/PT | PIC16LC67-04/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-44 (10x10 mm) | TQFP-44 (10x10 mm) - same | TQFP-44 (10x10 mm) - same | MQFP-44 (10x10 mm) - same | TQFP-44 (10x10 mm) - same | TQFP-44 (10x10 mm) - same |
| Program Memory | 7 KB OTP | 7 KB Flash | 7 KB Flash | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| Max Clock Speed | 4 MHz | 20 MHz | 20 MHz | 4 MHz | 4 MHz | 4 MHz |
| A/D Converter | 8 ch, 8-bit | 8 ch, 8-bit | 14 ch, 10-bit | 8 ch, 8-bit | None | 8 ch, 8-bit |
| Operating Voltage | 3.0 - 6.0 V | 2.0 - 5.5 V | 2.0 - 5.5 V | 3.0 - 6.0 V | 3.0 - 6.0 V | 3.0 - 6.0 V |
| Operating Temperature | 0 C to +70 C | -40 C to +85 C | -40 C to +85 C | 0 C to +70 C | -40 C to +85 C | 0 C to +70 C |
| Lifecycle Status | NRND | Active | Active | NRND | NRND | NRND |
| I/O Pins | 33 | 33 | 36 | 33 | 33 | 33 |
Key Differentiators
- Direct Flash upgrade path on identical TQFP-44 footprint (vs PIC16F74-I/PT)
- PIC16LC74AT-04/PT offers integrated A/D and USART on-chip (vs PIC16LC65AT-04I/PT)
- Same TQFP-44 package allows direct PCB reuse vs MQFP-44 variant (vs PIC16LC74A-04/PQ)
Design Notes
Place a 100 nF ceramic decoupling capacitor close to each VDD pin (pins 26, 38, 42) and a 10 uF bulk capacitor at the regulator output. The MCLR/VPP pin (pin 44) requires a 10 kohm pull-up to VDD and a 100 nF capacitor to ground for proper reset behavior; do not leave MCLR floating. Keep the OSC1/OSC2 traces short (less than 5 mm) and guard them with a ground ring to reduce EMI pickup. Use a four-layer PCB with a continuous ground plane beneath the TQFP-44 to minimize digital switching noise coupling into the analog inputs.
The PIC16LC74AT-04/PT uses One-Time-Programmable memory: once a bit is programmed from '1' to '0' it cannot be reset. Plan firmware revisions carefully and always verify code with a Flash equivalent (PIC16F74-I/PT) before committing to OTP programming for production. Early silicon revisions had a known Timer1 anomaly described in the device errata; review the latest Microchip errata document for the PIC16C7X family before relying on Timer1 for time-critical applications. Do not exceed 6.0V on VDD or the OTP memory cells may be accidentally programmed.
For reliable in-circuit serial programming (ICSP) leave the RB6/PGC (pin 33) and RB7/PGD (pin 34) lines accessible to the programming header without crossing other signal traces. Place the ICSP connector at the board edge with a 0.1 inch header footprint (5 pins: VPP, VDD, VSS, PGC, PGD). Keep analog inputs (RA0-RA5) routed away from high-frequency digital signals; add a ground guard ring around the analog section of the PORTA pins. The CCP1 (RC2) and CCP2 (RC1) PWM outputs should be routed directly to driver circuits with short trace lengths and series ferrite beads if driving motors.
Compliance Information
PIC16LC74AT-04/PT was released in 1997 (per FindIC datasheet publication date) and pre-dates modern RoHS/REACH compliance disclosures; verify current compliance with Microchip's product environmental compliance page. This part is not AEC-Q100 qualified; for AEC-Q100 applications use the PIC16F74-I/PT industrial-grade variant.