PIC16C56-LPI/SO - 8-bit 40MHz OTP MCU, 1.5KB, 12 I/O | Microchip
MPN: PIC16C56-LPI/SO β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.21 | $2.21 |
| 10 | $1.97 | $19.70 |
| 100 | $1.74 | $174.00 |
| 500 | $1.52 | $760.00 |
| 1,000 | $1.31 | $1,310.00 |
PIC16C56-LPI/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (ROM/Flash/OTP), working RAM, and programmable I/O peripherals into one package. Within the broader taxonomy, the PIC16C56 belongs to the 8-bit microcontroller category, which sits under the microcontroller family, then embedded processors, and finally the integrated circuit hierarchy. The PIC16C5x series occupies the entry-level/low-cost node of Microchip's 8-bit portfolio and is widely used in cost-sensitive, deterministic control loops where a few milliamps of I/O drive and a few hundred bytes of RAM are sufficient.
Key features include a 7-stage or 8-stage special-function register file, a two-level deep hardware call stack, direct/indirect/relative addressing modes for both data and instructions, and an 8-bit real-time clock/counter (TMR0). The CMOS process delivers low power consumption across the 2.0V-6.25V operating range, while the 12 I/O pins support direct LED drive and TTL/CMOS-compatible logic levels.
Architecturally, the PIC16C56 uses a Harvard RISC-like core with single-cycle instruction execution (except branches) and an OTP EPROM program memory that is one-time programmable, making it suited for low-volume mature designs rather than field-upgradable firmware. The 12-bit wide instruction path provides efficient encoding for byte-oriented control code.
Typical applications include appliance control, remote controls, security peripherals, sensor interfaces, and consumer white-goods sub-systems. The wide operating temperature and 12 I/O count make it adaptable to compact industrial or commercial embedded designs. The PIC16C56-LPI/SO is recommended for new designs only when the OTP nature and 1.5KB code limit align with the production profile; engineers should evaluate Flash-based PIC16F5x alternatives for new development where field reprogrammability is required.
Drop-in alternatives for PIC16C56-LPI/SO β 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-LPI/SO (same form factor and footprint) β differing in RoHS Status, Core Architecture, Oscillator Type, Package, Operating Temperature.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C56-LPE/SO
β Drop-Inβ In Stock
$2.18 / Unit
View Datasheet βPIC16C56-LP/SO
β Drop-Inβ In Stock
$1.82 / Unit
View Datasheet βPIC16C56-HSI/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16F54-I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C56A-04/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C56-LPI/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC (Harvard) |
| Instruction Set Width | 12-bit |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 1.5KB (1K x 12) |
| RAM | 25 bytes |
| I/O Pins | 12 |
| CPU Speed | 40 MHz maximum |
| Timers | 1 x 8-bit (TMR0 with prescaler) |
| Hardware Stack | 2 levels |
| Addressing Modes | Direct, Indirect, Relative |
| Special Function Registers | 7 (or 8) hardware registers |
| Supply Voltage | 2.0 V to 6.25 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 18-pin SOIC (SO, .300" body) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (lead-free finish, see notes) |
PIC16C56-LPI/SO Pin Configuration
| Pin 1 | RA2 β Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 β Bidirectional I/O port A bit 3 |
| Pin 3 | RA4/T0CKI β Bidirectional I/O port A bit 4 / Timer0 clock input |
| Pin 4 | MCLR/VPP β Master Clear (reset) input / Programming voltage |
| Pin 5 | VSS β Ground reference |
| Pin 6 | RB0 β Bidirectional I/O port B bit 0 |
| Pin 7 | RB1 β Bidirectional I/O port B bit 1 |
| Pin 8 | RB2 β Bidirectional I/O port B bit 2 |
| Pin 9 | RB3 β Bidirectional I/O port B bit 3 |
| Pin 10 | RB4 β Bidirectional I/O port B bit 4 |
| Pin 11 | RB5 β Bidirectional I/O port B bit 5 |
| Pin 12 | RB6 β Bidirectional I/O port B bit 6 |
| Pin 13 | RB7 β Bidirectional I/O port B bit 7 |
| Pin 14 | VDD β Positive supply voltage |
| Pin 15 | OSC2/CLKOUT β Oscillator output / Clock output |
| Pin 16 | OSC1/CLKIN β Oscillator input / External clock input |
| Pin 17 | RA0 β Bidirectional I/O port A bit 0 |
| Pin 18 | RA1 β Bidirectional I/O port A bit 1 |
Typical Applications
PIC16C56-LPI/SO is suitable for 6 applications: Appliance Control (Washing Machines, Dishwashers), Remote Controls and IR Keyboards, Security and Alarm Peripherals, Sensor Interface Modules, Consumer White-Goods Sub-Systems, Automotive Interior Sub-Modules.
Appliance Control (Washing Machines, Dishwashers)
The PIC16C56-LPI/SO is well-suited to white-goods control boards where the BOM is tight and firmware is locked at production release. Its 1.5KB OTP program memory and 25 bytes of RAM cover typical motor-control state machines for pumps, valves, and timers, while the 12 I/O pins drive relays, triacs, and indicator LEDs directly without external buffers. Operating from 2.0V to 6.25V across -40C to +85C, it tolerates the electrical noise and temperature swings of an appliance cabinet. Pair with a ULN2003A for high-current driver expansion; reference the PIC16C5X family datasheet for triac-zero-crossing timing examples.
Recommended
Remote Controls and IR Keyboards
Battery-powered IR remote designs benefit from the PIC16C56-LPI/SO's low CMOS quiescent current, 2.0V minimum supply (single 2xAA operation), and 12 I/O sufficient to scan a 4x4 keypad matrix plus an IR LED driver. The 8-bit TMR0 provides accurate 38kHz carrier timing for NEC/RC-5 protocols, and the 1.5KB code space holds complete protocol encoders with key debounce. Industrial temperature grade supports automotive and outdoor use cases. Use it with a TSOP38238 IR receiver for closed-loop testing.
Recommended
Security and Alarm Peripherals
In PIR motion sensors, glass-break detectors, and door/window contact modules, the PIC16C56-LPI/SO delivers low-cost, deterministic control with OTP memory preventing post-deployment firmware tampering. The 12 I/O accommodate a PIR analog front-end, status LEDs, tamper switch, piezo buzzer PWM, and a relay or logic output to the alarm panel. The 40MHz instruction rate lets the firmware sample the PIR signal at sufficient rate to discriminate noise from genuine motion events. Pair with an RE200B PIR sensor and an MCP602 op-amp for the analog front-end.
Recommended
Sensor Interface Modules
The PIC16C56-LPI/SO works well in dedicated sensor-conditioning modules where the firmware is fixed and the unit cost must be minimized. Use it to read a thermistor, photodiode, or Hall-effect sensor via TMR0-gated counting or software ADC techniques, then transmit the result via a UART bit-banged on any I/O pin. The 2.0V to 6.25V supply range simplifies single-cell or 3.3V system integration. Recommended companions are the MCP9700 temperature sensor and a 4N35 optocoupler for isolated serial output.
Recommended
Consumer White-Goods Sub-Systems
Within a larger appliance, the PIC16C56-LPI/SO serves as a sub-controller for display panels, indicator rings, and buzzer drivers, offloading simple tasks from a more expensive main MCU. Its 12 I/O drive 7-segment LED displays directly through current-limit resistors, and the OTP memory locks the display firmware to prevent field confusion if a service center attempts to swap a board. Operating temperature -40C to +85C handles oven-door, refrigerator, and HVAC environments. Pair with TM1637 LED drivers for multi-digit 7-segment display expansion.
Recommended
Automotive Interior Sub-Modules
The PIC16C56-LPI/SO is found in mature automotive interior controllers such as dome-light timers, accessory delay modules, and simple HVAC mode selectors where the -40C to +85C industrial temperature range and EMI resilience of the PIC16C5x core deliver decades of field-proven reliability. OTP firmware prevents unauthorized feature changes, while 12 I/O handle switches, LEDs, and a single relay driver. For new automotive designs, prefer PIC16F1xx with AEC-Q100 qualification; the C56 remains viable for cost-sensitive legacy service replacements.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56-LPI/SO β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C56-LPI/P | PIC16C56-LPE/SO | PIC16C56-LP/SO | PIC16C56-HSI/SO | PIC16F54-I/SO | PIC16C56A-04/SO |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SOIC-18 | PDIP-18 | SOIC-18 | SOIC-18 | SOIC-18 | SOIC-18 | SOIC-18 |
| Program Memory | 1.5KB OTP | 1.5KB OTP | 1.5KB OTP | 1.5KB OTP | 1.5KB OTP | 0.75KB Flash | 1.5KB OTP |
| RAM | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 | 12 |
| Max Clock | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 20 MHz | 4 MHz |
| Supply Voltage | 2.0V to 6.25V | 2.0V to 6.25V | 2.0V to 6.25V | 2.0V to 6.25V | 2.0V to 6.25V | 2.0V to 5.5V | 2.0V to 6.25V |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +125C (extended) | 0C to +70C (commercial) | -40C to +85C | -40C to +85C | -40C to +85C |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | Flash | OTP EPROM |
Key Differentiators
- Industry-standard 12-bit OTP core with 25+ years of toolchain maturity (vs PIC16F54-I/SO)
- Pin-compatible with the entire PIC16C5x SOIC-18 family (vs PIC16C55-LPI/SO)
- 40MHz instruction rate matches PIC16C55/C57/C58A family (vs PIC16C56A-04/SO)
Design Notes
The PIC16C56 uses one-time-programmable EPROM: once programmed, the firmware cannot be erased or rewritten. Always validate firmware on a JW (windowed) or Flash equivalent (PIC16F54) part before committing to a production run. Errata sheets for the PIC16C5x family list specific issues (e.g., MCLR behavior under low VDD) that affect brownout design. Always include the recommended 10kohm pull-up on MCLR (pin 4) and a 100nF decoupling capacitor on VDD (pin 14) placed within 5mm of the pin.
Decoupling: place a single 100nF X7R ceramic capacitor between VDD (pin 14) and VSS (pin 5) within 5mm of the package, with the trace loop area minimized. For SOIC-18, route VDD/VSS as wide traces or short pours to reduce inductive ringing when an output pin switches high-current loads like relays. Place the crystal or resonator as close as possible to OSC1/OSC2 (pins 16/15) with the load capacitors grounded to the same VSS pin via a star topology to minimize jitter.
I/O pin sink/source current is typically 25mA per pin but total port current must not exceed the per-package port maximum (typically 100mA for port B). When driving multiple LEDs or relay coils, distribute the load across both ports and verify against the absolute maximum DC ratings table. For long PCB traces to external loads, add a 100ohm series resistor close to the PIC pin to dampen transmission-line ringing. When using TMR0 as an external counter (pin 3, RA4/T0CKI), keep the trace short and avoid routing near switching loads.
Estimated: at 5V supply, 20MHz oscillator, and 12 I/O switching at 50% duty, the PIC16C56-LPI/SO draws approximately 10-15 mA active and <1 microamp in sleep mode (with TMR0 disabled). For battery-powered designs, leverage the SLEEP instruction and wake via Watchdog Timer or port-change interrupt to extend battery life to multi-year timescales. Brownout behavior is not internally managed on all PIC16C5x variants; add an external voltage supervisor (e.g., MCP100) if the application requires guaranteed reset below 2.0V.
Compliance Information
RoHS compliant with lead-free matte-tin finish per Microchip product page. Not AEC-Q100 qualified; for new automotive designs select PIC16F1xx or PIC18F AEC-Q100 variants. REACH SVHC statement available from Microchip upon request.
