PIC16LC74A-04/L - 8-Bit 7KB OTP MCU 4MHz | Microchip PLCC-44
MPN: PIC16LC74A-04/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.95 | $6.95 |
| 10 | $6.12 | $61.20 |
| 100 | $5.48 | $548.00 |
| 500 | $4.85 | $2,425.00 |
| 1,000 | $4.32 | $4,320.00 |
PIC16LC74A-04/L Overview
What is an OTP microcontroller? An OTP MCU is a one-time-programmable variant of flash/EPROM-based microcontrollers where the program memory can be written exactly once using a programming tool, after which the code becomes permanent. Compared to UV-erasable EPROM MCUs, OTP parts offer lower cost, smaller package options, and faster programming cycles, making them typical in mass-production embedded products. The PIC16LC74A-04/L belongs to the PIC16C family, which sits between PIC10/PIC12 baseline parts and the PIC18 enhanced family in Microchip's 8-bit MCU taxonomy.
Key differentiating features include 13 interrupt sources, 8-level hardware stack, 3 timer/counter modules, a USART/SCI serial port, MSSP (SPI/I2C) peripheral, Capture/Compare/PWM (CCP) module, and 8 channels of 8-bit A/D conversion. The "LC" suffix denotes a CMOS low-voltage variant that consumes less power than the standard "C" part, while the "04" speed grade denotes a 4 MHz maximum oscillator frequency.
Typical applications include industrial control systems, appliance controls, sensor signal conditioning nodes, automotive body modules, low-cost instrumentation, and remote-control transmitter logic. The 33 I/O count and integrated peripherals make it especially useful for designs that need analog sensing plus digital I/O without an external ADC.
Designers should note the OTP memory constraint: firmware must be fully verified before programming because the part cannot be reprogrammed. For development, consider the PIC16F74 (flash) variant on the same 44-pin PLCC footprint. A 100 nF decoupling capacitor close to VDD and proper oscillator layout are essential for reliable operation.
Drop-in alternatives for PIC16LC74A-04/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 PIC16LC74A-04/L (same form factor and footprint) — differing in Mounting Type, Package, Program Memory Size, Data EEPROM, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC74AT-04/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC74A-04I/L
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.79 / Unit
View Datasheet →PIC16LC74B-04/L
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.95 / Unit
View Datasheet →PIC16C74A-04/L
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC16LC74A-04/L Maximum Ratings & Electrical Characteristics
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| CPU Architecture | 8-bit RISC |
| Maximum Clock Frequency | 4 MHz |
| Operating Voltage Range | 2.5 V to 5.5 V |
| RAM Size | 192 bytes |
| Data EEPROM | None |
| I/O Pins | 33 |
| ADC | 8-channel, 8-bit |
| Timers | 3 (Timer0, Timer1, Timer2) |
| Serial Peripherals | USART/SCI, MSSP (SPI/I2C) |
| Capture/Compare/PWM | Yes (CCP module) |
| Interrupt Sources | 13 |
| Hardware Stack | 8 levels |
| Package | 44-pin PLCC (16.59 x 16.59 mm) |
| Mounting Type | Surface Mount (PLCC J-lead) |
| Temperature Grade | Commercial |
PIC16LC74A-04/L Pin Configuration
| Pin 1 | OSC1/CLKI — Oscillator input / external clock input |
| 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 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 / read control / analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / write control / analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / chip select / analog input 7 |
| Pin 11 | VDD — Digital supply voltage |
| Pin 12 | VSS — Digital ground |
| Pin 13 | OSC2/CLKO — Oscillator output / clock output |
| Pin 14 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator out / Timer1 clock in |
| Pin 15 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator in / CCP2 |
| Pin 16 | RC2/CCP1 — PORTC bit 2 / CCP1 |
| Pin 17 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 18 | RD0/PSP0 — PORTD bit 0 / parallel slave port bit 0 |
| Pin 19 | RD1/PSP1 — PORTD bit 1 / parallel slave port bit 1 |
| Pin 20 | RD2/PSP2 — PORTD bit 2 / parallel slave port bit 2 |
| Pin 21 | RD3/PSP3 — PORTD bit 3 / parallel slave port bit 3 |
| Pin 22 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 23 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 24 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 25 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 26 | RD4/PSP4 — PORTD bit 4 / parallel slave port bit 4 |
| Pin 27 | RD5/PSP5 — PORTD bit 5 / parallel slave port bit 5 |
| Pin 28 | RD6/PSP6 — PORTD bit 6 / parallel slave port bit 6 |
| Pin 29 | RD7/PSP7 — PORTD bit 7 / parallel slave port bit 7 |
| Pin 30 | AVSS — Analog ground |
| Pin 31 | AVDD — Analog supply voltage |
| Pin 32 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 33 | RB1 — PORTB bit 1 |
| Pin 34 | RB2 — PORTB bit 2 |
| Pin 35 | RB3 — PORTB bit 3 |
| Pin 36 | RB4 — PORTB bit 4 |
| Pin 37 | RB5 — PORTB bit 5 |
| Pin 38 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 39 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 40 | NC — Not connected (per datasheet) |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | MCLR/VPP — Master clear reset / programming voltage |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16LC74A-04/L is suitable for 6 applications: Industrial Control Systems, Appliance Control Boards, Sensor Signal Conditioning Nodes, Automotive Body Modules, Low-Cost Instrumentation, Remote-Control Transmitter Logic.
Industrial Control Systems
The PIC16LC74A-04/L is well suited to industrial control systems thanks to its 33 digital I/O pins and integrated 8-channel 8-bit ADC. In a typical PLC-style application it directly reads analog sensor voltages on eight inputs while driving relays and indicators through PORTA/PORTB/PORTC digital lines. The 4 MHz instruction rate, 192 bytes of RAM, and 7-KB OTP program space support finite-state-machine logic and modest control loops. Its 2.5V to 5.5V supply range is tolerant of loosely regulated 24 V-derived rails stepped down by simple linear regulators, and the PLCC-44 package accepts sockets that simplify board rework.
Recommended
Appliance Control Boards
The PIC16LC74A-04/L fits white-goods and small-appliance controllers where its OTP memory locks firmware permanently, preventing accidental field reprogramming. Its 33 I/O pins drive triacs for AC loads, read keypad matrices, and control LED or seven-segment displays directly. The MSSP peripheral reads EEPROM for user settings while the USART links to inverter boards at modest baud rates. With 192 bytes of RAM and a 7 KB program budget, the device runs main-loop appliance logic with adequate headroom. The 44-pin PLCC package survives thermal cycling in hot compartments and supports sockets for service replacements.
Recommended
Sensor Signal Conditioning Nodes
Sensor-conditioning front ends benefit from the PIC16LC74A-04/L's 8-channel 8-bit ADC and three timer modules, which together sample, average, and time-multiplex multiple analog inputs. The on-chip USART/SCI streams conditioned values upstream while MSSP runs an I2C link to a local digital sensor. With 33 I/O pins, the controller directly drives alert LEDs and buzzer outputs without external glue logic. The 4 MHz instruction cycle, 192 bytes of RAM, and 7-KB OTP budget are sufficient for moving-average filters plus calibration constants stored in firmware, and the 2.5 V to 5.5 V range supports direct battery operation.
Recommended
Automotive Body Modules
Automotive body-electronics modules use the PIC16LC74A-04/L for non-safety functions where its 33 I/O pins and 7 KB OTP program memory handle lighting, wiper, lock, and accessory logic. The PIC16LC74A-04I/L (industrial -40 to +85 C grade) is preferable where wider thermal tolerance is required. With three timers plus the CCP module the controller generates PWM for lamp dimming and motor speed, and the USART links to body controllers. The PLCC-44 package suits automotive assembly lines that prefer socketed MCU footprints for serviceability, and the LC variant's 2.5 V to 5.5 V supply range tolerates 12 V-derived rails.
Recommended
Low-Cost Instrumentation
Entry-level bench instruments and panel meters adopt the PIC16LC74A-04/L because its integrated 8-bit ADC and three timers digitize analog signals without external converter chips, while the USART streams measurements to a host PC or display. The 7 KB OTP budget stores calibration constants plus display formatting routines, and 192 bytes of RAM buffers averaging algorithms. The MSSP drives an I2C OLED or LCD display, while PORTA digital pins accept rotary encoder inputs. The 4 MHz instruction cycle is sufficient for sample-and-display loops under 100 Hz, and the LC variant's low-voltage tolerance helps in battery-powered handhelds.
Recommended
Remote-Control Transmitter Logic
The PIC16LC74A-04/L's three timer modules plus its CCP module make it suitable for encoder and transmitter logic in custom RF or infrared remote-control units. The 33 I/O pins accept multi-button keypads with matrix wiring, while the USART or PWM output drives an external RF stage or LED modulator. With 192 bytes of RAM and 7 KB of OTP, the controller runs button-debounce state machines, rolling-code, and channel selection logic. The LC variant's 2.5 V to 5.5 V supply range enables operation directly from coin cells or two AA batteries, and the 44-pin PLCC supports development sockets for OEM pre-flashing.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC74A-04/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC74AT-04/L | PIC16LC74A-04I/L | PIC16LC74B-04/L | PIC16C74A-04/L |
|---|---|---|---|---|---|
| Package | 44-pin PLCC (16.59 x 16.59 mm) | 44-pin PLCC - same | 44-pin PLCC - same | 44-pin PLCC - same | 44-pin PLCC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | OTP (7 KB / 4K x 14) | OTP (7 KB / 4K x 14) | OTP (7 KB / 4K x 14) | OTP (7 KB / 4K x 14) | OTP (7 KB / 4K x 14) |
| 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 | 4.0 V to 6.0 V |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Temperature Grade | Commercial (0C to +70C) | Commercial | Industrial (-40C to +85C) | Commercial | Commercial |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND |
Key Differentiators
- Wider 2.5 V to 5.5 V operating range vs PIC16C74A 4 V to 6 V (vs PIC16C74A-04/L)
- Commercial temperature grade option with 7 KB program space (vs PIC16LC74A-04I/L)
- PLCC package supports sockets for serviceability (vs PIC16C74A-04/P)
Design Notes
Estimated power budget - VDD = 5.0 V, I_ACTIVE approximately 2 mA at 4 MHz per PIC16C7X electrical characteristics. Place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD/VSS pins and a 10 uF bulk capacitor on the supply rail. Connect analog AVDD/AVSS to the same supply but route them through a ferrite bead and provide a local 100 nF decoupling cap, since ADC accuracy depends on a low-noise analog supply.
PLCC-44 socket footprint is recommended for OTP parts in development. The MCLR/VPP pin should have a 10 kohm pull-up to VDD and a 100 nF cap to ground for proper reset behavior. The OSC1/OSC2 pins must be kept away from high-current switching traces to avoid clock corruption, and the analog PORTA inputs should be guarded by ground traces to minimize crosstalk with the digital PORTD bus.
Because OTP memory is one-time programmable, production firmware must be fully verified before programming - any bug is permanent. Brown-out reset (BOR) configuration bits must be set appropriately for the 2.5 V to 5.5 V supply range; disabling BOR can cause undefined state during power-up. The ADC requires a minimum acquisition time; using faster ADC clock dividers than the datasheet minimums can corrupt conversions.
Compliance Information
RoHS, REACH, halogen-free status not explicitly stated in verified distributor data - mark as unknown. AEC-Q100 not applicable; this is a commercial-grade 8-bit MCU, not an automotive-qualified MCU.
