PIC16LC56A-04/SO - 1.5KB OTP 8-bit MCU 4MHz SOIC-18 | Microchip
MPN: PIC16LC56A-04/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.34 | $1.34 |
| 10 | $1.18 | $11.80 |
| 100 | $0.95 | $95.00 |
| 500 | $0.85 | $425.00 |
| 1,000 | $0.78 | $780.00 |
PIC16LC56A-04/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, volatile data RAM, and peripheral I/O on one die. MCUs sit at the top of the embedded system hierarchy alongside DSPs, FPGAs, and ASICs, and the PIC16C5X family in particular pioneered the Harvard-architecture 8-bit RISC segment, delivering 12-bit-wide instructions with 2:1 code compression versus typical 8-bit CISC competitors, which translates into higher effective code density per kilobyte of program memory.
Key features include a 4 MHz maximum clock rate, a 33-instruction RISC core with 12-bit opcode width, two 8-bit I/O ports (Port A and Port B) totaling 12 I/O lines, a programmable watchdog timer, an 8-bit real-time counter/counter (TMR0) with programmable prescaler, and power-saving SLEEP mode. The OTP memory is one-time programmable, making this part well suited to volume production runs that do not require firmware updates in the field.
The PIC16LC56A-04/SO uses a Harvard architecture with separate program and data buses, enabling single-cycle instruction fetch except for program branches. The four-megahertz internal oscillator divider and the integrated power-on reset and brown-out detect (not always present on the 16C5X base line, please verify per revision) simplify external circuitry. The "-04" speed suffix designates the 4 MHz maximum clock, distinguishing it from the "-10" and "-20" variants that operate at higher frequencies.
Typical applications include low-cost consumer appliances, remote control transmitters, sensor signal conditioning front-ends, battery-powered timer products, automotive body electronics modules, and simple industrial control replacement of discrete logic. The 12 I/O lines comfortably drive LED arrays, keypads, small character LCDs and relay or triac interfaces. The wide 3V to 6.25V supply range is friendly to both 3.3V and 5V rails.
When designing with this device, plan the OTP programming step into your production flow because OTP cannot be erased or rewritten. Reserve a 100 nF decoupling capacitor close to VDD and a 10 kohm pull-up on MCLR, and verify timing margins at the worst-case 4 MHz and the minimum VDD of 3.0V, since CMOS RISC cores can slow dramatically near the lower supply bound.
This page synthesizes distributor pricing across Mouser, LCSC and Jotrin, parametric alternatives from the PIC16C5X pin-compatible family, and practical design notes that go beyond the bare Microchip datasheet.
Drop-in alternatives for PIC16LC56A-04/SO — 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 PIC16LC56A-04/SO (same form factor and footprint) — differing in Program Memory Size, Watchdog Timer, Package, Core Architecture, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC56AT-04/SO
✅ Drop-In✓ In Stock
$2.75 / Unit
View Datasheet →PIC16LC56A-04I/SO
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC16LC558-04I/SO
✅ Drop-In✓ In Stock
$1.1 / Unit
View Datasheet →PIC16LC558T-04/SO
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →PIC16LC554T-04/SO
✅ Drop-In✓ In Stock
$3.85 / Unit
View Datasheet →PIC16LC554T-04I/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC16LC56A-04/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit RISC (PIC16C5X family) |
| Program Memory Size | 1.5 KB (1K x 12) OTP |
| RAM Size | 25 bytes |
| Maximum Clock Frequency | 4 MHz |
| Supply Voltage (VDD) | 3.0 V to 6.25 V |
| Number of I/O Pins | 12 |
| Number of Timers | 1 x 8-bit (TMR0) |
| Watchdog Timer | Yes (software enabled) |
| Instruction Set Width | 12-bit opcode, 33 instructions |
| Package Type | SOIC-18 (300 mil) |
| Memory Type | OTP (One-Time Programmable) |
| Operating Temperature Range | 0C to +70C (Commercial) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (unlimited floor life at <30C / 85% RH) |
| RoHS Status | Compliant |
| Lead-Free / Halogen-Free | Lead-free (per Microchip product page) |
PIC16LC56A-04/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 3 | T0CKI — Timer0 external clock input / RA4 |
| Pin 4 | MCLR — Master clear reset (active low), 10 kohm pull-up to VDD |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Bidirectional I/O port B bit 0 |
| Pin 7 | RB1 — Bidirectional I/O port B bit 1 |
| Pin 8 | RB2 — Bidirectional I/O port B bit 2 |
| Pin 9 | RB3 — Bidirectional I/O port B bit 3 |
| Pin 10 | RB4 — Bidirectional I/O port B bit 4 |
| Pin 11 | RB5 — Bidirectional I/O port B bit 5 |
| Pin 12 | RB6 — Bidirectional I/O port B bit 6 |
| Pin 13 | RB7 — Bidirectional I/O port B bit 7 |
| Pin 14 | VDD — Positive supply voltage (3.0 V to 6.25 V) |
| Pin 15 | OSC2 — Oscillator output; crystal or resonator connection |
| Pin 16 | OSC1 — Oscillator input; crystal, resonator, or external clock |
| Pin 17 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 18 | RA1 — Bidirectional I/O port A bit 1 |
Typical Applications
PIC16LC56A-04/SO is suitable for 6 applications: Remote Control Transmitter, Consumer Appliance Timer, Battery-Powered Sensor Front-End, LED Lighting Controller, Automotive Accessory Module, Replacement of Discrete Logic.
Remote Control Transmitter
The PIC16LC56A-04/SO is a strong fit for handheld IR/RF remote control transmitters because its 12 I/O pins directly drive a 4x3 keypad matrix and a power-efficient IR LED without external glue logic. At 4 MHz the RISC core executes all scanning and encoding tasks with sub-millisecond latency, while the 1.5 KB OTP memory holds typical RC5, NEC, or SIRC protocol encoders. The 3.0 V to 6.25 V supply range supports both 3 V coin-cell and 5 V wall-adapter rails.
Recommended
Consumer Appliance Timer
Microwave ovens, washing machines, and small kitchen appliances use the PIC16LC56A-04/SO as the central timer controller because the integrated watchdog timer (WDT) and TMR0 counter provide reliable long-duration timing without external RTC chips. The 4 MHz clock is fast enough to multiplex 7-segment LED displays and scan a 4x4 button matrix at 50 Hz refresh, while the 25-byte RAM comfortably holds mode and timing state. OTP code protection prevents reverse engineering of proprietary cooking cycles.
Recommended
Battery-Powered Sensor Front-End
For battery-powered temperature, humidity, or motion sensor front-ends, the PIC16LC56A-04/SO offers a useful combination of wide supply range (3.0 V to 6.25 V) and an ultra-low-power SLEEP mode that drops current consumption below 1 microampere between sensor reads. The 12-bit instruction width compresses typical sensor fusion code by roughly 2:1 versus CISC 8-bit alternatives, fitting more logic into the 1.5 KB OTP budget. Two AA cells or a CR2032 coin cell can power the design for years with proper duty-cycling.
Recommended
LED Lighting Controller
Addressable RGB LED string controllers, decorative lighting, and small DMX-style fixtures use the PIC16LC56A-04/SO to bit-bang WS2812B or APA102 LED protocols from a 4 MHz instruction cycle. The 12 I/O pins can drive multiple LED data lines plus a button input and a status LED. OTP code lock prevents competitors from cloning proprietary lighting patterns, an important consideration for the consumer LED market.
Recommended
Automotive Accessory Module
Aftermarket automotive accessories such as alarm LED indicators, seat-heater timers, and lighting controllers deploy the PIC16LC56A-04/SO because the wide 3.0 V to 6.25 V supply range tolerates the 6 V to 16 V automotive bus after a simple LDO pre-regulator. The RISC core's deterministic 1 microsecond per instruction cycle simplifies timing-critical CAN-bus-like bit-banging, while the SOIC-18 footprint fits in the tight enclosures typical of dashboard accessories.
Recommended
Replacement of Discrete Logic
Designers can replace a board full of 74HC-series glue logic with a single PIC16LC56A-04/SO, achieving lower BOM cost and easier design updates late in the development cycle. The 12 I/O pins implement any combinational or sequential logic up to several hundred gate equivalents, and the 1.5 KB OTP holds complex timing and state-machine logic that would require dozens of TTL packages in a discrete design.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC56A-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC56AT-04/SO | PIC16LC56A-04I/SO | PIC16LC558-04I/SO | PIC16LC558T-04/SO | PIC16LC554T-04/SO | PIC16LC554T-04I/SO |
|---|---|---|---|---|---|---|---|
| Package | SOIC-18 | SOIC-18 | SOIC-18 | SOIC-18 | SOIC-18 | SOIC-18 | SOIC-18 |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 2 KB OTP | 2 KB OTP | 0.875 KB OTP | 0.875 KB OTP |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Supply Voltage | 3.0 V to 6.25 V | 3.0 V to 6.25 V | 3.0 V to 6.25 V | 3.0 V to 6.25 V | 3.0 V to 6.25 V | 3.0 V to 6.25 V | 3.0 V to 6.25 V |
| Operating Temperature | 0C to +70C (Commercial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) |
| I/O Pins | 12 | 12 | 12 | 13 | 13 | 13 | 13 |
| Unit Price (qty 1000) | $0.78 | $0.78 | $0.85 | $0.92 | $0.92 | $0.70 | $0.78 |
Key Differentiators
- Widest supply voltage range in its OTP class (vs PIC16C56A-04/SO)
- Industrial temperature option with identical pinout (vs PIC16LC56A-04I/SO)
- Pin-compatible upgrade to 2 KB and 13 I/O without PCB changes (vs PIC16LC558-04I/SO)
Design Notes
Place a 100 nF ceramic decoupling capacitor as close as possible to the VDD pin (pin 14) and a 10 uF bulk capacitor near the SOIC-18 power entry. The PIC16LC56A-04/SO draws roughly 2 mA active at 4 MHz and 6.25 V; using a smaller decoupling network risks logic errors during switching transients. Tie MCLR (pin 4) to VDD through a 10 kohm resistor and add a 100 nF cap to ground for clean brown-out-free reset behavior at the lower 3.0 V supply bound.
Keep the oscillator traces from OSC1 (pin 16) and OSC2 (pin 15) short, symmetrical, and surrounded by a grounded guard ring. Use a 4 MHz ceramic resonator with built-in load capacitors for cost-sensitive designs, or a crystal with two 22 pF caps to VSS for designs that demand precise timing such as UART bit-banging. Route the MCLR trace away from switching signals to avoid spurious resets in electrically noisy environments.
OTP memory cannot be erased or rewritten, so always prototype with a Flash-based sibling such as PIC16F84A-04/SO or PIC16F88-I/SO and finalize firmware before committing to PIC16LC56A-04/SO production. Also confirm the supply voltage is at least 3.0 V at the VDD pin under full load; below 3.0 V the RISC core slows dramatically and brown-out conditions may not trigger a clean reset, leading to corrupted EEPROM-emulated data or watchdog timeouts.
The SOIC-18 package has a theta_JA of approximately 85 C/W, which is fine for the PIC16LC56A-04/SO's modest 50 mW typical dissipation. No heatsink is required even at 6.25 V and 4 MHz continuous operation. However, if you operate above 70C ambient, derate by 1 mW per C and consider the industrial-grade PIC16LC56A-04I/SO variant for higher temperature headroom.
Compliance Information
RoHS and lead-free status confirmed on Microchip product page; halogen-free status not explicitly listed in the verified data and is marked unknown. AEC-Q100 is not applicable because this part targets consumer and industrial applications, not automotive under-hood use.
