PIC16C56-LP/P - 8-bit 40MHz 1.5KB OTP MCU 18-PDIP | Microchip
MPN: PIC16C56-LP/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.33 | $5.33 |
| 10 | $4.93 | $49.30 |
| 100 | $4.43 | $443.00 |
| 500 | $3.86 | $1,930.00 |
| 1,000 | $3.39 | $3,390.00 |
PIC16C56-LP/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and peripheral interfaces such as I/O ports, timers, and possibly analog or communication blocks. The PIC16C5x family belongs to the original baseline PIC architecture, classified within the 8-bit microcontroller hierarchy: 8-bit MCU -> RISC microcontroller -> embedded controller -> semiconductor IC. This family uses a 12-bit-wide instruction word with single-cycle execution across 33 instructions, achieving 2:1 code compression versus earlier 8-bit competitors.
Key features include 1.5KB OTP program memory, 25 bytes of general-purpose RAM, 12 bidirectional I/O lines, an 8-bit real-time clock/counter (TMR0) with 8-bit prescaler, a 2-level deep hardware stack, and support for direct, indirect, and relative addressing modes. The LP suffix denotes the low-power CMOS oscillator option, optimized for crystal or RC operation at lower frequencies (typically 32.768 kHz to 200 kHz) for reduced quiescent current. Seven to eight special-function hardware registers provide the control interface.
Architecturally, the device is fully static, employing a RISC pipeline with single-cycle instruction fetch and execution. The Harvard-style separate program and data buses, combined with the 12-bit instruction width, enable deterministic timing suitable for direct bit-banged protocols. The two-level hardware stack constrains subroutine nesting to two levels, with deeper nesting requiring software stack emulation in RAM.
Typical applications include low-power battery-operated devices, simple appliance controllers, hardware-replacement glue logic, RC servo control, IR remote transmitters, and educational/training kits. The wide operating voltage range (commonly 2.5 V to 6.0 V) and low-power oscillator make it well-suited to coin-cell or 2xAA powered systems.
When designing with this part, note that OTP memory cannot be reprogrammed, so the device is best used in volume production or in-circuit emulation workflows. For field-upgradable firmware, consider the flash-based PIC16F5x equivalent family in the same package.
This page synthesizes distributor inventory, drop-in compatible alternatives from the same PIC16C5x family, and practical design notes not found in a single manufacturer datasheet.
Drop-in alternatives for PIC16C56-LP/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 PIC16C56-LP/P (same form factor and footprint) — differing in Package, Program Memory Type, Timers, RoHS Status, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C55-LP/P
✅ Drop-In✓ In Stock
$1.45 / Unit
View Datasheet →PIC16C56-HS/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C56-HSI/P
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC16C56A-04E/P
✅ Drop-In✓ In Stock
$1.21 / Unit
View Datasheet →PIC16F54-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C55-XT/P
✅ Drop-In✓ In Stock
$4.05 / Unit
View Datasheet →PIC16C56-LP/P Maximum Ratings & Electrical Characteristics
| Core | PIC16C5x 8-bit RISC |
| Instruction Set | 33 single-word/single-cycle instructions (12-bit wide) |
| Maximum Clock Frequency | 40 MHz |
| Program Memory Type | OTP (One-Time-Programmable) |
| Program Memory Size | 1.5 KB (1K x 12) |
| RAM Size | 25 bytes |
| I/O Pins | 12 |
| Timers | 1 x 8-bit (TMR0) with 8-bit prescaler |
| Hardware Stack | 2 levels |
| Addressing Modes | Direct, Indirect, Relative |
| Special Function Registers | 7 to 8 |
| Oscillator Mode | LP (Low-Power Crystal/RC) |
| Package | 18-PDIP (0.300 in / 7.62 mm) |
| Mounting Type | Through-Hole |
| Operating Temperature Grade | Commercial |
PIC16C56-LP/P Pin Configuration
| Pin 1 | RA2 — PORT A bit 2 (bidirectional I/O) |
| Pin 2 | RA3 — PORT A bit 3 (bidirectional I/O) |
| Pin 3 | T0CKI — Timer0 clock input / RA4 |
| Pin 4 | /MCLR — Master Clear (reset) input, active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — PORT B bit 0 (bidirectional I/O) |
| Pin 7 | RB1 — PORT B bit 1 (bidirectional I/O) |
| Pin 8 | RB2 — PORT B bit 2 (bidirectional I/O) |
| Pin 9 | RB3 — PORT B bit 3 (bidirectional I/O) |
| Pin 10 | RB4 — PORT B bit 4 (bidirectional I/O) |
| Pin 11 | RB5 — PORT B bit 5 (bidirectional I/O) |
| Pin 12 | RB6 — PORT B bit 6 (bidirectional I/O) |
| Pin 13 | RB7 — PORT B bit 7 (bidirectional I/O) |
| Pin 14 | VDD — Positive supply voltage (2.5 V to 6.0 V) |
| Pin 15 | OSC2 — Oscillator output (crystal/RC) |
| Pin 16 | OSC1 — Oscillator input (crystal/RC) |
| Pin 17 | RA0 — PORT A bit 0 (bidirectional I/O) |
| Pin 18 | RA1 — PORT A bit 1 (bidirectional I/O) |
Typical Applications
PIC16C56-LP/P is suitable for 6 applications: Battery-Powered Sensor Node, Remote Control / IR Transmitter, Appliance Timer / Simple Sequencer, Hardware Replacement Glue Logic, Educational Microcontroller Trainer, Toy and Game Electronics.
Battery-Powered Sensor Node
The PIC16C56-LP/P is well suited to ultra-low-power battery-operated sensor nodes where the LP oscillator drives a 32.768 kHz crystal for sub-microamp quiescent current draw. Its 1.5KB OTP program memory and 25 bytes RAM comfortably hold periodic wake-measure-sleep firmware for temperature, humidity, or contact sensors that transmit every few seconds via a simple UART or GPIO bit-bang. The 2.5V to 6.0V operating range directly supports 2xAA alkaline or single LiCoin cells without additional regulation. Compared to higher-end Cortex-M0+ MCUs, the 12-bit instruction RISC core keeps active current below 2 mA at 4 MHz while preserving deterministic timing for sensor sampling windows. The 8-bit TMR0 with 8-bit prescaler enables accurate long-interval wake scheduling, and the 2-level hardware stack is sufficient for the single interrupt service routine and main loop typical of sensor firmware.
Recommended
Remote Control / IR Transmitter
Consumer IR remote controls and RF key fobs traditionally use PIC16C5x baseline devices because the RISC architecture provides deterministic bit timing for 38 kHz carrier generation. The PIC16C56-LP/P's 12 I/O pins accommodate up to 8 matrix-scan keypad rows/columns plus dedicated TX and LED drive outputs, while the 1.5KB OTP holds complete RC5, NEC, or SIRC protocol stacks with button debounce and repetition logic. The LP oscillator at 32.768 kHz is ideal for idle standby, and the core can switch to an internal or higher-frequency source only during active transmission to extend coin-cell life. Compared to software-RTOS solutions on larger MCUs, the zero-overhead interrupt and direct bit manipulation on PORTB keep firmware response latency below 50 microseconds for tight carrier timing.
Recommended
Appliance Timer / Simple Sequencer
Household appliances such as washing-machine sub-assemblies, microwave keypads, and dishwasher controllers have long relied on PIC16C5x devices for fixed-sequence state machines. The PIC16C56-LP/P's OTP memory stores validated production firmware permanently, eliminating field firmware corruption risk in harsh electrical environments. TMR0 with the 8-bit prescaler generates precise 1 ms to 1 s tick intervals used to advance state, debounce switches, and drive TRIAC/relay outputs via the 12 I/O pins. The commercial 0C to +70C operating range covers indoor appliance enclosures, and the 40 MHz instruction throughput handles up to 20 simultaneous GPIO toggles per millisecond. Compared to complex Cortex controllers, the deterministic 1-instruction-per-cycle execution makes firmware timing analysis straightforward and EMI behavior predictable.
Recommended
Hardware Replacement Glue Logic
When discrete 74HC logic becomes too large or expensive, designers migrate to a PIC16C56-LP/P programmed as a single-chip state machine. With 12 I/O pins and 33 instructions, the device can replace dozens of discrete gates implementing counters, decoders, multiplexers, and waveform generators. The OTP memory locks the logic permanently, preventing inadvertent reprogramming in the field. The 25-byte RAM provides scratchpad storage for state variables, while the 8-bit TMR0 serves as a free-running event counter or PWM generator. Compared to discrete logic, a PIC16C56-LP/P design reduces PCB area by 70 percent and power consumption by 80 percent while making the design reprogrammable for last-minute logic changes during NPI.
Recommended
Educational Microcontroller Trainer
Universities, technical schools, and hobbyist training kits have used PIC16C5x devices for over two decades because the small instruction set (33 instructions) can be taught in a single semester. The PIC16C56-LP/P provides enough code space for student projects involving keypad input, 7-segment display driving, motor PWM, and serial communication while remaining inexpensive enough to issue one per student. The 18-PDIP through-hole package is breadboard-friendly and survives repeated insertion cycles during lab sessions. The LP oscillator supports a low-cost 32.768 kHz watch crystal or simple RC network, eliminating the need for expensive precision oscillators in classroom settings. Compared to modern ARM-based trainer boards, the PIC16C56-LP/P's simplicity lets students focus on core embedded concepts without debugger or toolchain complexity.
Recommended
Toy and Game Electronics
Mass-produced electronic toys, talking plush dolls, and novelty games typically use baseline PIC microcontrollers like the PIC16C56-LP/P because the OTP memory locks production firmware against piracy while keeping per-unit cost below fifty cents at volume. The 12 I/O pins drive LED eyes, sound chips, motor H-bridges, and pushbutton inputs typical of interactive toys. The 1.5KB program memory holds complex sound-effect sequencing and reaction-game logic in a single device. Operating from 2xAA cells at 3 V nominal, the device runs directly without a regulator, simplifying BOM and shrinking the PCB to fit inside small toy enclosures. Compared to off-the-shelf toy ICs, custom PIC firmware differentiates the product while the OTP memory prevents cloning by competitors.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56-LP/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55-LP/P | PIC16C56-HS/P | PIC16C56-HSI/P | PIC16C56A-04E/P | PIC16F54-I/P |
|---|---|---|---|---|---|---|
| Package | 18-PDIP (0.300 in) | 18-PDIP - same | 18-PDIP - same | 18-PDIP - same | 18-PDIP - same | 18-PDIP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1.5 KB OTP | 0.75 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP (enhanced) | 0.5 KB Flash |
| RAM | 25 bytes | 24 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| Oscillator Mode | LP (low-power) | LP (low-power) | HS (high-speed) | HS (high-speed) | XT (crystal) | INTOSC + LP/HS/XT |
| Temperature Grade | Commercial (0C to +70C) | Commercial | Commercial | Industrial | Extended | Industrial |
| Memory Type | OTP | OTP | OTP | OTP | OTP (enhanced) | Flash (reprogrammable) |
| Core | PIC16C5x 8-bit RISC | PIC16C5x 8-bit RISC | PIC16C5x 8-bit RISC | PIC16C5x 8-bit RISC | PIC16C5x enhanced | PIC16F 8-bit RISC |
Key Differentiators
- Larger program memory than the PIC16C55 sibling (vs PIC16C55-LP/P)
- Field-reprogrammable flash alternative available in same footprint (vs PIC16F54-I/P)
- Low-power oscillator option for battery applications (vs PIC16C56-HS/P)
- Extended family pin-compatibility for design flexibility (vs PIC16C56A-04E/P)
Design Notes
Estimated: at VDD = 5 V and 32.768 kHz LP oscillator, the PIC16C56-LP/P draws approximately 15 to 20 microamps active and under 1 microamp in sleep mode per the Microchip PIC16C5x datasheet (DS30412D). The LP oscillator option is specifically designed for low-frequency crystal operation to minimize quiescent current. For battery-life calculations, assume 20 microamps average active current with 1 percent duty cycle, yielding ~16 mAh/year - a CR2032 coin cell (220 mAh) will last more than 13 years. Add a 0.1 microfarad decoupling capacitor within 5 mm of the VDD pin and a 10 microfarad bulk capacitor if the supply impedance exceeds 1 ohm.
The PIC16C56-LP/P uses OTP program memory, meaning firmware is locked at production programming and cannot be field-updated. For development, prototype with the flash-based PIC16F54-I/P in the same 18-PDIP package and migrate only after firmware is frozen. The 2-level hardware stack means subroutines cannot nest deeper than 2 levels - if you need more, emulate a software stack in the 25-byte RAM. The /MCLR pin (pin 4) must be pulled to VDD through a 10k resistor or driven high; leaving it floating causes intermittent resets. The T0CKI pin (pin 3) requires careful PCB routing if used as a clock input to avoid coupling noise into the oscillator circuit.
Keep the crystal or resonator within 5 mm of the OSC1/OSC2 pins (pins 16/15) and surround both traces with a ground pour to minimize EMI pickup. The /MCLR pull-up resistor (typically 10k) should be placed close to pin 4; if not using external reset, tie pin 4 directly to VDD. Decoupling: place a 0.1 microfarad ceramic between VDD (pin 14) and VSS (pin 5) within 3 mm of the package. If switching high-current loads through PORT B outputs, add 100 ohm series resistors to limit inrush current that could cause VDD dips and clock instability. Keep digital I/O traces away from the OSC1/OSC2 area to avoid corrupting the low-power oscillator waveform.
Compliance Information
RoHS and lead-free compliance confirmed per Microchip product page. Not AEC-Q100 qualified - this is a commercial-grade OTP MCU. For automotive applications use AEC-Q100 qualified variants from the PIC16F family.
