PIC16LC74BT-04I/L - 8-bit 4MHz MCU 7KB OTP 44-PLCC | Microchip
MPN: PIC16LC74BT-04I/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $10.47 | $10.47 |
| 10 | $9.92 | $99.20 |
| 100 | $9.42 | $942.00 |
| 500 | $8.8 | $4,400.00 |
| 1,000 | $8.2 | $8,200.00 |
PIC16LC74BT-04I/L Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, data memory, and peripheral interfaces on one die. Within the broader taxonomy, the PIC16LC74B belongs to the Mid-Range PIC16 architecture (14-bit instruction word, RISC core) which sits between the Base-Line PIC10/PIC12/PIC16C5x family and the Enhanced Mid-Range PIC16F1xxx family. The PIC16LC74B is a power-management-conscious derivative using a low-voltage CMOS process, and ultimately falls under the 8-bit MCU category within embedded microcontrollers and semiconductor ICs.
Key features of the PIC16LC74BT-04I/L include a Harvard-architecture 8-bit RISC core with a 14-bit instruction set, built-in peripherals such as Brown-out Detect/Reset, Power-on Reset (POR), Pulse-Width Modulation (PWM) outputs, and a Watchdog Timer (WDT). The device also integrates analog and digital resources, including an 8-bit ADC, multiple timers (5 x 8-bit plus 1 x 16-bit), and a 5 x 8-bit structure that maps I/O, timer, and interrupt resources. Connectivity is provided by one I2C/SPI interface and one UART/USART channel, supporting common industrial networking protocols.
The device utilizes Microchip's standard OTP EPROM-based program memory, which is mask-programmed during manufacturing and cannot be erased electrically. This makes the PIC16LC74BT-04I/L a production-targeted part for designs where the firmware is stable, cost-sensitive, and high-volume. The "T" suffix indicates a tape-and-reel packaging option, while "/L" specifies the leadless 44-PLCC surface-mount package with J-bend terminations.
Typical applications include industrial control panels, appliance controllers, automotive sub-system modules, sensor signal conditioning, and low-power embedded products where the 2.5V minimum supply enables direct battery or 3.3V-rail operation. The wide temperature range makes the part suitable for HVAC, factory automation, and outdoor instrumentation.
A key design consideration is the trade-off between OTP memory (no in-field updates) and Flash-based siblings such as PIC16F74. Engineers targeting a stable, low-cost, high-volume product should select the OTP "C" variant, but should prototype using the PIC16F74 Flash version to allow firmware iteration. Designers should also note the 33 I/O pin budget against the 44-pin PLCC assignments and ensure proper decoupling on VDD/AVDD/VDDCORE pins.
This page synthesizes distributor pricing, drop-in alternative options from the same PIC16C family, and practical design notes not consolidated in any single manufacturer document.
Drop-in alternatives for PIC16LC74BT-04I/L — 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 PIC16LC74BT-04I/L (same form factor and footprint) — differing in Mounting Type, Operating Temperature Range, Program Memory Size, Program Memory Type, Instruction Cycle Time.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C74B-04I/L
✅ Drop-In✓ In Stock
$2.61 / Unit
View Datasheet →PIC16C74B-04/L
✅ Drop-In✓ In Stock
$3.32 / Unit
View Datasheet →PIC16LC74B-04I/L
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$6.95 / Unit
View Datasheet →PIC16LC74B-04I/P
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.12 / Unit
View Datasheet →PIC16C74A-04I/L
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16LC74AT-04I/L
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16LC74BT-04I/L Maximum Ratings & Electrical Characteristics
| Core | 8-bit PIC RISC (Mid-Range PIC16, 14-bit instruction word) |
| Program Memory Type | OTP (One-Time-Programmable EPROM) |
| Program Memory Size | 7 KB (4K x 14) |
| RAM | 192 bytes |
| Maximum Clock Frequency | 4 MHz |
| Operating Voltage Range | 2.5 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Number of I/O Pins | 33 |
| Package Type | 44-pin PLCC (16.59 x 16.59 mm, J-bend) |
| ADC | 8-bit, 8 channels |
| Timers | 5 x 8-bit + 1 x 16-bit |
| Connectivity | I2C, SPI, UART/USART |
| Integrated Peripherals | Brown-out Detect/Reset, POR, PWM, WDT |
| Mounting Type | Surface Mount |
PIC16LC74BT-04I/L 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 — PORTA bit 2 / analog input channel 2 |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / analog channel 3 / ADC reference positive |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / analog channel 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / parallel port read / analog channel 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / parallel port write / analog channel 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / parallel port chip select / analog channel 7 |
| Pin 11 | VDD — Positive digital supply (2.5V to 5.5V) |
| Pin 12 | VSS — Digital ground |
| 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 / Capture-Compare-PWM 2 |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / Capture-Compare-PWM 1 |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 20 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 21 | RC6/TX/CK — PORTC bit 6 / UART transmit / I2C clock (slave mode) |
| Pin 22 | RC7/RX/DT — PORTC bit 7 / UART receive / I2C data (slave mode) |
| Pin 23 | VSS — Digital ground |
| Pin 24 | AVDD — Analog positive supply |
| Pin 25 | AVSS — Analog ground |
| Pin 26 | VREF- — ADC negative reference |
| 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 / low-voltage programming |
| 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 | RD0/PSP0 — PORTD bit 0 / parallel slave port bit 0 |
| Pin 36 | RD1/PSP1 — PORTD bit 1 / parallel slave port bit 1 |
| Pin 37 | RD2/PSP2 — PORTD bit 2 / parallel slave port bit 2 |
| Pin 38 | RD3/PSP3 — PORTD bit 3 / parallel slave port bit 3 |
| Pin 39 | RD4/PSP4 — PORTD bit 4 / parallel slave port bit 4 |
| Pin 40 | RD5/PSP5 — PORTD bit 5 / parallel slave port bit 5 |
| Pin 41 | RD6/PSP6 — PORTD bit 6 / parallel slave port bit 6 |
| Pin 42 | RD7/PSP7 — PORTD bit 7 / parallel slave port bit 7 |
| Pin 43 | AVDD — Analog positive supply (redundant pin) |
| Pin 44 | AVSS — Analog ground (redundant pin) |
Typical Applications
PIC16LC74BT-04I/L is suitable for 7 applications: Industrial Control Panels, Home Appliance Controllers, Automotive Body Electronics Sub-Modules, Sensor Signal Conditioning & Data Acquisition Front-Ends, HVAC and Building Automation, Low-Power Embedded Battery Products, Legacy Production Sustaining Designs.
Industrial Control Panels
The PIC16LC74BT-04I/L suits industrial HMI and control panels where deterministic 8-bit response and an industrial -40C to +85C grade are required. The 4 MHz/1 MIPS core, 33 I/O lines, and PWM peripherals handle relay drivers, indicator LEDs, and panel-switch matrix scanning, while Brown-out Detect/Reset and WDT provide robust field recovery. Designers typically pair the MCU with opto-isolated inputs and the 8-bit ADC for analog sensor conditioning inside 24V panels.
Recommended
Home Appliance Controllers
In white-goods controllers such as washing machines, dishwashers, and microwave ovens, the PIC16LC74BT-04I/L's 33 I/O and PWM outputs directly drive triac/relay actuators, motor control signals, and seven-segment or LCD user-interface displays. The 192-byte RAM and 7KB OTP accommodate fixed-function appliance firmware, and the 2.5V to 5.5V supply allows direct 5V or 3.3V regulator operation. The OTP memory locks the appliance firmware against in-field tampering once production is locked.
Recommended
Automotive Body Electronics Sub-Modules
The PIC16LC74BT-04I/L operates in automotive body-electronics sub-modules such as seat controllers, mirror adjusters, and climate-control heads, where its industrial temperature grade and PWM/USART peripherals fit interior 12V-bus subsystems. Its 8-channel 8-bit ADC reads sensor inputs (temperature, position, current) while PWM signals drive small DC-motor H-bridges. Note that for safety-critical automotive domains an AEC-Q100-qualified part is required; the PIC16LC74B family is generally non-automotive-graded.
Recommended
Sensor Signal Conditioning & Data Acquisition Front-Ends
The PIC16LC74BT-04I/L acts as a low-cost data-acquisition front end for industrial sensors. Its 8-channel 8-bit ADC samples strain gauges, thermistors, or 4-20 mA loop sensors, while the I2C/SPI peripheral connects to external EEPROM, RTC, or DAC companions. With 192 bytes of RAM and serial comms, the part can buffer small packets before forwarding them to a host PLC or SCADA concentrator across UART. The 2.5V minimum supply enables battery-powered remote sensor nodes.
Recommended
HVAC and Building Automation
The PIC16LC74BT-04I/L fits HVAC thermostats, fan-coil controllers, and building-automation nodes because it offers reliable -40C to +85C operation, 5 x 8-bit plus 1 x 16-bit timers for scheduling PWM outputs, and a Watchdog Timer for unattended operation. The 4 MHz core, brown-out reset, and POR combine for resilient start-up after power-cycling in equipment rooms. Multiple PWM channels can drive TRIAC/SSR heating and 3-speed fan stages from the same MCU.
Recommended
Low-Power Embedded Battery Products
The "LC" low-voltage CMOS core enables the PIC16LC74BT-04I/L to run directly from a 3.3V rail or single-cell lithium-ion post-regulator, with operating voltage down to 2.5V. This makes it attractive for battery-powered instrumentation, wireless sensor nodes (paired with a discrete RF companion), and portable handheld tools where the 4 MHz instruction budget meets modest compute needs. The 192-byte RAM and 7KB OTP support typical wireless-protocol stack control loops.
Recommended
Legacy Production Sustaining Designs
Because the PIC16LC74BT-04I/L is obsolete and uses OTP memory, the most common ongoing application is sustaining legacy production lines where firmware is locked and field-installed units need identical replacement MCUs. Industrial OEM customers with multi-decade service contracts (energy metering, elevator controllers, and railroad signaling auxiliaries) keep the part in scope specifically because OTP prevents accidental firmware drift on shipped units.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC74BT-04I/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74B-04I/L | PIC16C74B-04/L | PIC16LC74B-04I/L | PIC16LC74B-04I/P | PIC16C74A-04I/L | PIC16LC74AT-04I/L |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-PLCC | 44-PLCC (same) | 44-PLCC (same) | 44-PLCC (same) | 44-PLCC (same) | 44-PLCC (same) | 44-PLCC (same) |
| Core | 8-bit PIC16 RISC (Mid-Range) | 8-bit PIC16 RISC (same) | 8-bit PIC16 RISC (same) | 8-bit PIC16 RISC (same) | 8-bit PIC16 RISC (same) | 8-bit PIC16 RISC (same) | 8-bit PIC16 RISC (same) |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Operating Voltage | 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 |
| Temperature Grade | Industrial -40C to +85C | Industrial -40C to +85C | Commercial 0C to +70C | Industrial -40C to +85C | Industrial -40C to +85C | Industrial -40C to +85C | Industrial -40C to +85C |
| Packaging Suffix | Tape and Reel ("T") | Tube (no T suffix) | Tube (no T suffix) | Tube (no T suffix) | Tube (no T suffix) | Tube (no T suffix) | Tape and Reel (T suffix) |
| Lifecycle Status | Obsolete | Obsolete (per Microchip) | Obsolete (per Microchip) | Obsolete (per Microchip) | Obsolete (per Microchip) | Obsolete (per Microchip) | Obsolete (per Microchip) |
Key Differentiators
- Industrial OTP silicon with tape-and-reel packaging (vs PIC16C74B-04/L)
- Low-voltage CMOS "LC" core for 2.5V operation (vs PIC16C74B-04/L)
- Same 44-PLCC pinout as the Flash-based PIC16F74B successor (vs PIC16C74B-04I/L)
Design Notes
Do NOT select the PIC16LC74BT-04I/L for new designs as of 2026-09-22. The part is in obsolete lifecycle status and uses One-Time-Programmable memory, so firmware cannot be updated in the field. Use the Flash-based PIC16F74B-I/L on the same 44-PLCC footprint for any new development. Reserving the OTP "C" variant solely for legacy sustaining designs is the recommended design rule.
Decouple VDD/AVDD with 0.1 uF and 10 uF capacitors placed within 5 mm of the supply pins, per the Microchip PIC16C74B datasheet layout guidance. Tie the AVDD/AVSS pins on a 44-PLCC footprint to their corresponding supplies even if the ADC is unused, and route analog and digital grounds to a single point to prevent digital switching noise from coupling into ADC channels. Brown-out Detect must be enabled in configuration fuses for industrial deployments to avoid spurious reset behavior.
Place the 4 MHz crystal or resonator within 10 mm of the OSC1/OSC2 pins and keep the oscillator traces over a continuous ground plane. Avoid routing high-speed switching signals (PWM outputs, parallel-slave-port lines) across the MCLR/VPP pin or near the ICSP PGC/PGD pins, as capacitive coupling can corrupt in-circuit programming. For the 44-PLCC socketed application, ensure the PLCC socket retention clip grounds properly to prevent ESD-induced latch-up on the I/O pins.
Compliance Information
This part is OTP CMOS silicon in a 44-PLCC J-bend package; RoHS/REACH/lead-free/halogen-free/conflict-mineral data was not provided in the verified web data and is therefore marked unknown. AEC-Q100 status is not applicable (not qualified per Microchip nomenclature; automotive applications require explicit AEC-Q100-grade parts).
