PIC16LC74B-04I/PT - 8-Bit MCU, 7KB OTP, 4MHz, 44-TQFP | Microchip
MPN: PIC16LC74B-04I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.95 | $9.95 |
| 10 | $8.96 | $89.60 |
| 100 | $7.96 | $796.00 |
| 500 | $7.16 | $3,580.00 |
| 1,000 | $6.37 | $6,370.00 |
PIC16LC74B-04I/PT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (ROM/Flash/OTP), data memory (RAM), and peripheral interfaces such as timers, ADC, and serial I/O onto one die. Within the PIC family hierarchy, the PIC16C74B belongs to the mid-range 8-bit core, situated between baseline (PIC10/12/14) and enhanced mid-range/PIC18 families. MCUs are foundational components in embedded systems, enabling deterministic real-time control in everything from consumer appliances to industrial automation.
Key features of the PIC16LC74B-04I/PT include 33 digital I/O lines, on-chip peripherals (typically including a USART, MSSP for SPI/I2C, capture/compare/PWM modules, and an 8-channel 8-bit ADC), and the low-power CMOS design typical of the LC family. The /I suffix designates the industrial temperature range (-40C to +85C), while /PT specifies the 44-lead Thin Quad Flat Pack (TQFP). The 4 MHz maximum oscillator frequency reflects the part's position in the early-2000s PIC16C generation.
Architecturally, the PIC16LC74B uses a Harvard-style 14-bit instruction word with separate program and data buses, providing deterministic single-cycle instruction execution (except branches). The 4 MHz oscillator yields a 1 microsecond instruction cycle, suitable for many control loops without external clock multiplication. The 33 I/O pins can be multiplexed across analog/digital functions and external interrupts.
Typical applications include industrial control boards, sensor signal conditioning and acquisition front-ends, low-power consumer appliances, simple motor control, and legacy embedded system maintenance. The OTP memory makes it suitable for low-volume production runs where mask-ROM economics do not apply.
When designing with this part, plan for OTP programming infrastructure, since OTP cannot be reprogrammed in-circuit after the cover-window seal is broken. Ensure decoupling (0.1 uF + 10 uF) is placed close to VDD/VSS pins, and verify that all unused I/O lines are configured as outputs low or inputs with pull-ups.
This page synthesizes verified distributor pricing, package-compatible drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16LC74B-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 PIC16LC74B-04I/PT (same form factor and footprint) — differing in Mounting Type, Program Memory Size, Capture/Compare/PWM, Data EEPROM, Instruction Cycle Time.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC74B-04I/PQ
✅ Drop-In✓ In Stock
$7.6 / Unit
View Datasheet →PIC16LC74A-04/PQ
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.43 / Unit
View Datasheet →PIC16C74B-04I/L
✅ Drop-In✓ In Stock
$2.61 / Unit
View Datasheet →PIC16LC74B-04/PQ
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$7.74 / Unit
View Datasheet →PIC16LF74-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC74B-04I/P
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.12 / Unit
View Datasheet →PIC16LC74B-04I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C mid-range 8-bit RISC |
| Program Memory Size | 7 KB (4K x 14) OTP |
| Data Memory (RAM) | 192 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 1 us at 4 MHz |
| Supply Voltage Range | 2.5 V to 6.0 V |
| I/O Pins | 33 |
| Package Type | 44-TQFP (PT) |
| Mounting Type | Surface Mount |
| Temperature Range | -40C to +85C (Industrial, /I suffix) |
| ADC | 8-channel, 8-bit (per datasheet family) |
| USART | Yes (per datasheet family) |
| MSSP (SPI/I2C) | Yes (per datasheet family) |
| Capture/Compare/PWM | Yes (per datasheet family) |
| ROM Type | OTP (One-Time Programmable) |
PIC16LC74B-04I/PT Pin Configuration
| Pin 1 | OSC1/CLKIN — Oscillator crystal input or external clock input |
| Pin 2 | RA0/AN0 — Port A bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 — Port A bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2 — Port A bit 2 / Analog input 2 |
| Pin 5 | RA3/AN3/VREF — Port A bit 3 / Analog input 3 / ADC reference |
| Pin 6 | RA4/T0CKI — Port A bit 4 / Timer 0 clock input |
| Pin 7 | RA5/AN4/SS — Port A bit 5 / Analog input 4 / SPI slave select |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 10 | RC0/T1OSO/T1CKI — Port C bit 0 / Timer 1 oscillator output / clock input |
| Pin 11 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer 1 oscillator input / CCP2 |
| Pin 12 | RC2/CCP1 — Port C bit 2 / Capture-Compare-PWM 1 |
| Pin 13 | RC3/SCK/SCL — Port C bit 3 / SPI clock / I2C clock |
| Pin 14 | RD0/PSP0 — Port D bit 0 / Parallel Slave Port bit 0 |
| Pin 15 | RD1/PSP1 — Port D bit 1 / Parallel Slave Port bit 1 |
| Pin 16 | RD2/PSP2 — Port D bit 2 / Parallel Slave Port bit 2 |
| Pin 17 | RD3/PSP3 — Port D bit 3 / Parallel Slave Port bit 3 |
| Pin 18 | RC4/SDI/SDA — Port C bit 4 / SPI data in / I2C data |
| Pin 19 | RC5/SDO — Port C bit 5 / SPI data out |
| Pin 20 | RC6/TX/CK — Port C bit 6 / USART transmit / clock |
| Pin 21 | RC7/RX/DT — Port C bit 7 / USART receive / data |
| Pin 22 | RD4/PSP4 — Port D bit 4 / Parallel Slave Port bit 4 |
| Pin 23 | RD5/PSP5 — Port D bit 5 / Parallel Slave Port bit 5 |
| Pin 24 | RD6/PSP6 — Port D bit 6 / Parallel Slave Port bit 6 |
| Pin 25 | RD7/PSP7 — Port D bit 7 / Parallel Slave Port bit 7 |
| Pin 26 | VSS — Ground reference |
| Pin 27 | VDD — Positive supply voltage |
| Pin 28 | RB0/INT — Port B bit 0 / External interrupt |
| Pin 29 | RB1 — Port B bit 1 |
| Pin 30 | RB2 — Port B bit 2 |
| Pin 31 | RB3 — Port B bit 3 |
| Pin 32 | RB4 — Port B bit 4 |
| Pin 33 | RB5 — Port B bit 5 |
| Pin 34 | RB6/PGC — Port B bit 6 / In-circuit debugger clock |
| Pin 35 | RB7/PGD — Port B bit 7 / In-circuit debugger data |
| Pin 36 | RE0/RD/AN5 — Port E bit 0 / Read control / Analog input 5 |
| Pin 37 | RE1/WR/AN6 — Port E bit 1 / Write control / Analog input 6 |
| Pin 38 | RE2/CS/AN7 — Port E bit 2 / Chip select / Analog input 7 |
| Pin 39 | VDD — Positive supply voltage |
| Pin 40 | VSS — Ground reference |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | MCLR/VPP — Master clear reset / Programming voltage input |
Typical Applications
PIC16LC74B-04I/PT is suitable for 6 applications: Industrial Control Boards, Sensor Signal Acquisition Front-Ends, Consumer Appliance Controllers, Legacy Embedded System Maintenance, Low-Power Remote Sensor Nodes, Educational and Training Platforms.
Industrial Control Boards
The PIC16LC74B-04I/PT's 4 MHz core and 33 I/O pins make it a workhorse for legacy industrial control applications such as sensor interfacing, relay driving, and contactor control. Its 2.5-6.0 V supply range tolerates noisy 5 V rails typical of factory-floor power, while the -40C to +85C industrial grade supports unconditioned enclosures. The 7 KB OTP memory accommodates multi-state control logic and lookup tables for protocol handling. According to the PIC16C73B/74B datasheet, on-chip peripherals include a USART and MSSP (SPI/I2C) for connecting to PLC backplanes, HMI displays, and sensor networks, while 8-channel 8-bit ADC handles analog transducer inputs. OTP keeps unit cost low for moderate production volumes.
Recommended
Sensor Signal Acquisition Front-Ends
With its on-chip 8-channel 8-bit ADC and 33 I/O, the PIC16LC74B-04I/PT can directly digitize multiple analog sensors in instrumentation modules. At 4 MHz instruction rate, ADC conversions (approx 20 us per the datasheet) are fast enough for low-bandwidth temperature, pressure, and flow-rate measurements. The 1 microsecond instruction cycle enables simple digital filtering and linearization in firmware. The wide 2.5-6.0 V supply accommodates battery or bus-powered sensor nodes. Industrial temp grade supports outdoor or factory installations. The OTP memory and modest 192-byte RAM keep these modules inexpensive for high-volume deployments.
Recommended
Consumer Appliance Controllers
The PIC16LC74B-04I/PT is well-suited for consumer appliances such as coffee machines, washing machines, microwave ovens, and HVAC controllers where cost dominates over performance. Its 33 I/O drive 7-segment displays, keypads, relay coils, and triac interfaces, while on-chip timers generate PWM for motor speed or heater regulation. The USART enables diagnostic ports or wireless module hookups. OTP memory keeps per-unit cost low for high-volume SKUs. Per the datasheet, the LC variant offers lower quiescent current than the C version, helping meet energy-star standby targets. Industrial temperature grade handles under-cabinet and garage installations.
Recommended
Legacy Embedded System Maintenance
Many products designed in the late 1990s and 2000s use PIC16C/LC OTP microcontrollers, and the PIC16LC74B-04I/PT is still purchased for spare-part replacement and ongoing production of long-lifecycle equipment. Its exact 44-TQFP pinout lets it drop into existing PCBs without rework. Industrial temp grade and proven reliability mean the part is favored in medical, aerospace, and military systems that must remain in service for decades. Where firmware bugs are discovered, OTP cannot be reprogrammed - so design revisions typically migrate to flash-based PIC16F74 or PIC16F1xxx families. For exact replica production, the LC OTP variant is preferred.
Recommended
Low-Power Remote Sensor Nodes
The PIC16LC74B-04I/PT's LC (low-power CMOS) process and 2.5-6.0 V supply make it suitable for battery-powered remote sensors transmitting over RS-485 or proprietary RF links. With sleep current typically under 10 uA (per datasheet family), it can wake periodically, sample sensors via its 8-channel ADC, and transmit via USART before returning to sleep. The 1 us instruction cycle is sufficient for simple averaging and threshold detection. Industrial temperature grade handles outdoor enclosures. OTP memory provides protection against firmware tampering in deployed sensor networks. Solar or lithium-thionyl-chloride battery packs can power the node for years.
Recommended
Educational and Training Platforms
The PIC16LC74B-04I/PT's mature toolchain (MPLAB X IDE, XC8 compiler, PICkit programmers) and abundant educational resources make it useful for university embedded-systems courses. Its 33 I/O support a wide range of peripheral exercises - LEDs, switches, UART terminals, SPI/I2C sensors, ADC inputs, PWM outputs. The 7 KB OTP forces careful memory budgeting, which is good pedagogical discipline. Industrial temp grade is forgiving of student lab environments. While modern courses prefer flash-based PIC16F or PIC18 parts, the LC OTP variant is excellent for understanding OTP programming flow, including UV-erase window behavior on windowed packages.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC74B-04I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC74B-04I/PQ | PIC16LC74A-04/PQ | PIC16C74B-04I/L | PIC16LC74B-04/PQ | PIC16LF74-I/PT | PIC16LC74B-04I/P |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (PT) | 44-MQFP (PQ) | 44-MQFP (PQ) | 44-PLCC (L) | 44-MQFP (PQ) | 44-TQFP (PT) | 40-PDIP (P) |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB Flash | 7 KB OTP |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Maximum Clock | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 4 MHz |
| Supply Voltage | 2.5-6.0 V | 2.5-6.0 V | 2.5-6.0 V | 4.0-6.0 V | 2.5-6.0 V | 2.0-6.0 V | 2.5-6.0 V |
| Temperature Range | -40C to +85C (I-grade) | -40C to +85C | -40C to +85C | -40C to +85C | 0C to +70C (commercial) | -40C to +85C | -40C to +85C |
| Memory Type | OTP | OTP | OTP | OTP | OTP | Flash (reprogrammable) | OTP |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 | 33 |
Key Differentiators
- Low-power CMOS process reduces quiescent current (vs PIC16C74B-04I/L)
- Reprogrammable memory for development and field updates (vs PIC16LF74-I/PT)
- Compact TQFP package for space-constrained designs (vs PIC16LC74B-04I/P)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor as close as possible to each VDD pin (pins 27 and 39 on the 44-TQFP), with a bulk 10 uF tantalum or aluminum capacitor at the board-level VDD entry. The PIC16LC74B-04I/PT operates over 2.5-6.0 V; ensure VDD rise time is less than 50 ms to guarantee proper Power-On Reset (POR). Add bulk capacitance if the supply is shared with high-current peripherals. Per Microchip PIC16C73B/74B datasheet recommendations, VDD must stabilize before the oscillator starts to avoid undefined reset states.
OTP memory cannot be erased or reprogrammed - once programmed, the PIC16LC74B-04I/PT is fixed. Verify firmware using a windowed or sample device before committing to OTP units. For development, use PIC16F74 (Flash variant) which shares the same pinout and peripherals. Always tie MCLR/VPP high through a 10 kohm resistor with a 100 nF decoupling cap; do not leave MCLR floating. Configure all unused I/O pins as outputs low or inputs with internal weak pull-ups enabled to minimize current draw.
Route the crystal/oscillator traces (OSC1 pin 1, OSC2 pin 9) short and symmetric, with ground guard traces around the crystal network. The 44-TQFP has its pins on all four sides with 0.80 mm pitch - allow adequate breakout room on inner PCB layers. Place the ICSP connector (PGC on RB6 pin 34, PGD on RB7 pin 35, MCLR/VPP on pin 44) so it does not require pin extensions for in-circuit programming. Reference: Microchip PIC16C73B/74B datasheet section on 'Oscillator Design'.
Compliance Information
RoHS/REACH/lead-free status not confirmed in verified data; PIC16C/LC family typically pre-dates RoHS standardization for many variants. Industrial /I temperature grade is per the PIC16C73B/74B datasheet family specification.