PIC16LC74B-04/P - 8-Bit 4MHz 7KB OTP MCU | Microchip Technology
MPN: PIC16LC74B-04/P ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.59 | $7.59 |
| 10 | $6.83 | $68.30 |
| 100 | $5.95 | $595.00 |
| 500 | $5.2 | $2,600.00 |
| 1,000 | $4.65 | $4,650.00 |
PIC16LC74B-04/P Overview
An 8-bit microcontroller (MCU) is a compact, single-chip computer built around an 8-bit data bus, integrating CPU core, program memory, data RAM, I/O peripherals, and timers onto one silicon die. PIC microcontrollers from the mid-range PIC16CXX family occupy the position of microcontrollers -> 8-bit MCU -> embedded controller -> semiconductor IC in the broader component taxonomy. Low-power (LC) variants such as the PIC16LC74B reduce supply current compared to standard PIC16C parts, extending battery life in portable and industrial designs.
Key features of the PIC16LC74B-04/P include 4K x 14 words of OTP program memory, 192 x 8 bytes of RAM, interrupt capability with up to 12 internal/external sources, and a fully-static CMOS design that allows DC to 4 MHz operation for the -04 speed grade. The 33 I/O pins individually support input or output direction, and integrated peripherals typically include timers, a USART, an SSP, and an 8-bit ADC depending on the PIC16CXX family variant. The 40-pin PDIP package is through-hole mounted for easy prototyping, breadboarding, and legacy system retrofits.
The PIC16LC74B architecture uses a Harvard-style memory map separating program (14-bit wide instruction words) and data spaces, which enables single-cycle instruction fetch except for program branches that require two cycles. This RISC-based approach simplifies coding while still providing deterministic timing for real-time control loops. Designers familiar with PIC mid-range assembly or C compilers such as XC8 can target the part with minimal learning curve.
Typical applications include industrial automation controllers, sensor interface modules, consumer white goods, low-power battery instruments, and educational embedded platforms where through-hole packages simplify repair and rework. The OTP memory makes the part suitable for mature, fixed-function designs where firmware will not require in-field updates.
When designing with the PIC16LC74B-04/P, confirm the oscillator configuration (RC, XT, LP, HS) matches the chosen crystal or resonator, and observe the maximum clock input of 20 MHz for the -04 speed grade (4 MHz maximum CPU clock). The OTP device cannot be reprogrammed, so production programming via a Microchip device programmer is mandatory before PCB assembly.
Drop-in alternatives for PIC16LC74B-04/P — 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-04/P (same form factor and footprint) — differing in Mounting Type, Core, Operating Temperature Range, Package, Program Memory.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC74B-04I/P
✅ Drop-In✓ In Stock
$2.12 / Unit
View Datasheet →PIC16C74B-04/PQ
✅ Drop-In✓ In Stock
$7.25 / Unit
View Datasheet →PIC16LC73B-04/SP
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.04 / Unit
View Datasheet →PIC16LC74B-04/P Maximum Ratings & Electrical Characteristics
| Product Family | PIC16CXX Mid-Range 8-bit MCU |
| Core | 8-bit RISC CPU |
| Instruction Set | 35 single-word instructions |
| CPU Speed (Max) | 4 MHz (DC to 4 MHz for -04 speed grade) |
| Clock Input (Max) | 20 MHz |
| Instruction Cycle | 200 ns at 20 MHz input |
| Program Memory | 7 KB (4K x 14 words) OTP |
| Data Memory (RAM) | 192 x 8 bytes |
| I/O Pins | 33 |
| Package | 40-pin PDIP (DIP-40) |
| Mounting Type | Through-Hole |
| Temperature Grade | Commercial |
| Architecture | Harvard, fully-static CMOS |
| Interrupt Sources | Up to 12 internal/external |
PIC16LC74B-04/P Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input or programming voltage |
| 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 / voltage reference |
| Pin 6 | RA4/T0CKI — Port A bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4 — Port A bit 5 / analog input 4 |
| Pin 8 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 9 | OSC2/CLKOUT — Oscillator output |
| Pin 10 | RC0/T1OSO/T1CKI — Port C bit 0 / Timer1 oscillator out / Timer1 clock |
| Pin 11 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer1 oscillator in / CCP2 |
| Pin 12 | RC2/CCP1 — Port C bit 2 / CCP1 |
| Pin 13 | RC3/SCK/SCL — Port C bit 3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — Port C bit 4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO — Port C bit 5 / SPI data out |
| Pin 16 | RC6/TX/CK — Port C bit 6 / USART TX / clock |
| Pin 17 | RC7/RX/DT — Port C bit 7 / USART RX / data |
| Pin 18 | RD0 — Port D bit 0 |
| Pin 19 | RD1 — Port D bit 1 |
| Pin 20 | RD2 — Port D bit 2 |
| Pin 21 | RD3 — Port D bit 3 |
| Pin 22 | RD4 — Port D bit 4 |
| Pin 23 | RD5 — Port D bit 5 |
| Pin 24 | RD6 — Port D bit 6 |
| Pin 25 | RD7 — Port D bit 7 |
| Pin 26 | RE0/RD — Port E bit 0 / read control |
| Pin 27 | RE1/WR — Port E bit 1 / write control |
| Pin 28 | RE2/CS — Port E bit 2 / chip select |
| Pin 29 | VSS — Ground reference |
| Pin 30 | VDD — Positive supply voltage |
| Pin 31 | OSC1 — Oscillator input (secondary) |
| Pin 32 | OSC2 — Oscillator output (secondary) |
| Pin 33 | RB0/INT — Port B bit 0 / external interrupt |
| Pin 34 | RB1 — Port B bit 1 |
| Pin 35 | RB2 — Port B bit 2 |
| Pin 36 | RB3 — Port B bit 3 |
| Pin 37 | RB4 — Port B bit 4 |
| Pin 38 | RB5 — Port B bit 5 |
| Pin 39 | RB6 — Port B bit 6 |
| Pin 40 | RB7 — Port B bit 7 |
Typical Applications
PIC16LC74B-04/P is suitable for 6 applications: Industrial Automation Controller, Sensor Interface Module, Consumer White Goods Control, Low-Power Battery Instrument, Educational Embedded Platform, Legacy Through-Hole Retrofit.
Industrial Automation Controller
The PIC16LC74B-04/P fits industrial automation controllers because its 33 I/O pins directly drive relays, sensors, and displays, and its 4 MHz CPU with 200 ns instruction cycle handles discrete logic loops in real time. Per Microchip application notes, the Harvard architecture delivers deterministic timing for PID-style control loops, while 192-byte RAM supports small state machines. The 40-pin PDIP through-hole package simplifies field replacement in legacy control panels where technicians need to swap chips with standard extraction tools.
Recommended
Sensor Interface Module
Sensor interface modules use the PIC16LC74B-04/P to read analog and digital sensors and convert measurements to digital outputs. The 33 I/O pins connect directly to switches, thermistors, and serial sensor chips, while the integrated ADC and USART peripherals handle signal conditioning. Per the PIC16CXX datasheet, the LC (low-power CMOS) process reduces quiescent current to extend battery life in remote sensor nodes, and the 7 KB OTP program memory stores fixed calibration tables for production runs.
Recommended
Consumer White Goods Control
Consumer white goods such as washing machines, dishwashers, and microwave ovens historically use the PIC16LC74B-04/P for appliance control boards. The 4 MHz CPU plus 33 I/O pins drive motor triacs, keypad scanning, and LED/LCD indicators, while the OTP memory locks firmware to prevent field tampering. The commercial 0C to +70C temperature grade covers typical indoor appliance environments, and the 40-pin PDIP package fits the through-hole assembly processes of mature appliance production lines.
Recommended
Low-Power Battery Instrument
Battery-powered instruments such as portable data loggers, handheld meters, and remote telemetry units benefit from the PIC16LC74B-04/P's LC low-power CMOS process. The device draws reduced quiescent current compared to standard PIC16C parts, and its fully-static core allows the clock to be stopped in sleep mode for months-long battery life. The 192-byte RAM holds sensor buffers between wake cycles, and the 33 I/O pins interface directly to battery-monitoring circuits and low-power transceivers.
Recommended
Educational Embedded Platform
The PIC16LC74B-04/P is widely deployed in university embedded systems labs and hobbyist electronics courses. The PIC mid-range architecture has 35 single-word instructions that are simple to teach in assembly, and the 7 KB OTP memory is large enough for substantial student projects while small enough to be fully understood. The 40-pin PDIP package is breadboard-friendly, allowing students to insert the chip directly into solderless breadboards without surface-mount soldering skills.
Recommended
Legacy Through-Hole Retrofit
Through-hole retrofits for legacy industrial and military equipment commonly use the PIC16LC74B-04/P because it preserves the original DIP-40 footprint. Per Microchip longevity programs, PIC16CXX devices remain available long after surface-mount equivalents have cycled, allowing field repair of equipment with no PCB rework. The 7 KB OTP memory also matches the original firmware patterns of vintage designs without requiring code porting.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC74B-04/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC74B-04I/P | PIC16C74B-04/P | PIC16LC73B-04/SP |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | PDIP-40 (DIP-40) | PDIP-40 (same) | PDIP-40 (same) | SPDIP-40 (same footprint) |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| Data RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| CPU Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| I/O Pins | 33 | 33 | 33 | 22 |
| Temperature Range | 0C to +70C (Commercial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | 0C to +70C (Commercial) |
| Power Variant | LC (low-power CMOS) | LC (low-power CMOS) | Standard C (higher Icc) | LC (low-power CMOS) |
Key Differentiators
- Low-power LC process for portable applications (vs PIC16C74B-04/P)
- Industrial temperature variant available on same footprint (vs PIC16LC74B-04I/P)
- 33 I/O pins vs 22 on smaller PIC16C73 (vs PIC16LC73B-04/SP)
Design Notes
The PIC16LC74B-04/P belongs to the LC (low-power CMOS) family and supports a wide 2.5V to 5.5V supply range. Estimated: at 5V VDD and 4 MHz CPU clock, typical Icc is in the 2-5 mA range; in sleep mode the device draws under 1 uA, making it suitable for battery-powered designs. Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of the VDD pin.
Route the oscillator traces (OSC1/OSC2 or pins 31-32 on the 40-pin DIP) as short as possible and keep them away from high-current traces to reduce EMI coupling. Per Microchip mid-range design notes, place the crystal or resonator within 10 mm of the MCU and provide a ground guard ring around the oscillator area on 2-layer boards.
Critical: the PIC16LC74B-04/P uses OTP memory which cannot be erased or rewritten. Production programmers must verify firmware before device programming because failed units are scrap. Also confirm the MCLR pin (pin 1) has a proper pull-up resistor (typically 10 kOhm) and is not left floating, otherwise the device will randomly enter reset state at power-up.
Compliance Information
RoHS and lead-free status not in the Verified Web Data; consult the manufacturer product page for definitive values. AEC-Q100 not applicable to commercial-temperature MCU. Conflict-mineral compliance per Microchip corporate policy.
