PIC16C56T-RCI/SO - 8-Bit 4MHz OTP MCU 1.5KB | Microchip
MPN: PIC16C56T-RCI/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.95 | $1.95 |
| 10 | $1.76 | $17.60 |
| 100 | $1.55 | $155.00 |
| 500 | $1.38 | $690.00 |
| 1,000 | $1.22 | $1,220.00 |
PIC16C56T-RCI/SO Overview
An 8-bit OTP microcontroller is a single-chip computer built around an 8-bit data path, executing one instruction per internal cycle and storing its program in EPROM that can be written exactly once. These devices sit in the hierarchy of microcontroller -> embedded controller -> semiconductor, and the PIC16C5X family specifically targets simple control loops, glue logic replacement, and low-cost consumer/industrial products where flash reprogrammability is unnecessary.
Key features include a Harvard architecture with separate program and data buses, 33 single-word/single-cycle instructions, a 4MHz maximum operating frequency yielding 1MHz instruction throughput (4:1 clock-to-instruction ratio), and an operating voltage range of 3.0V to 5.5V supporting both 3.3V and 5V rails. The 12-bit wide instruction set delivers typical 2:1 code compression over comparable 8-bit CISC microcontrollers, reducing program memory pressure on the 1K-word code space.
The PIC16C56T-RCI/SO employs a fully static CMOS design with low-power consumption, an internal RC oscillator option, and brown-out/reset circuitry suitable for battery-backed and mains-powered installations. The 18-pin SOIC (0.295 inch / 7.50 mm width) package provides a compact through-hole-compatible surface-mount footprint compatible with hand-soldering and standard 300-mil SOIC land patterns.
Typical applications include appliance control boards, HVAC thermostat interfaces, simple sensor signal conditioning front-ends, low-end remote controls, and industrial timer/counter modules. Designers also use the PIC16C56 in battery-powered sensor interfaces where its CMOS sleep current and internal oscillator minimize external component count.
When designing with this part, note that OTP memory cannot be re-programmed - choose the PIC16F56 flash-based alternative for prototyping and field updates. The 18-pin SOIC shares a pinout with most PIC16C5X family members (PIC16C54/55/57), enabling easy migration between family variants when memory or peripheral requirements change. Always validate code-protection settings before committing to OTP production programming.
This page synthesizes distributor pricing, drop-in PIC16C5X alternatives, and practical design notes that complement - not duplicate - the manufacturer datasheet.
Drop-in alternatives for PIC16C56T-RCI/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 PIC16C56T-RCI/SO (same form factor and footprint) — differing in Package, Core Architecture, Program Memory Size, Program Memory Type, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C55T-RCI/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.45 / Unit
View Datasheet →PIC16C56-RCI/SO
✅ Drop-In✓ In Stock
$0.99 / Unit
View Datasheet →PIC16C55T-HSI/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.2 / Unit
View Datasheet →PIC16C55T-LPI/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.49 / Unit
View Datasheet →PIC16C55T-RCE/SO
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C55-RCI/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.85 / Unit
View Datasheet →PIC16C56T-RCI/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC (Harvard) |
| Family | PIC16C5X (PIC16C56 sub-family) |
| Maximum Clock Frequency | 4 MHz |
| Instruction Throughput | 1 MIPS (4:1 clock-to-instruction) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 1.5 KB (1K x 12 words) |
| Data RAM | 25 bytes (8-bit) |
| Operating Voltage Range | 3.0 V to 5.5 V (3.3 V / 5 V) |
| I/O Pins | 12 |
| Timers | 1 x 8-bit watchdog/reset timer |
| Instruction Set | 33 instructions, 12-bit wide |
| Code Protection | Programmable via configuration bits |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 18-SOIC (0.295 inch / 7.50 mm width) |
| Mounting Type | Surface Mount (Tape & Reel) |
| Process Technology | CMOS |
PIC16C56T-RCI/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 | RTCC — Real-Time Clock/Counter input or I/O |
| Pin 4 | MCLR — Master Clear (Reset) input, active low |
| 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 (3.0V to 5.5V) |
| Pin 15 | OSC2 — Oscillator output / CLKOUT |
| Pin 16 | OSC1 — Oscillator input / CLKIN |
| Pin 17 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 18 | RA1 — Bidirectional I/O port A bit 1 |
Typical Applications
PIC16C56T-RCI/SO is suitable for 7 applications: Appliance Control Boards, HVAC Thermostat Interfaces, Remote Control Transmitters, Industrial Timer and Counter Modules, Sensor Signal Conditioning Front-Ends, Battery-Powered Sensor Interfaces, Consumer Electronics User Interface.
Appliance Control Boards
The PIC16C56T-RCI/SO is well-suited for cost-sensitive appliance control boards (washing machines, microwave ovens, dishwashers) because its 1.5KB OTP program memory and 33-instruction RISC core deliver reliable embedded control at minimum BOM cost. With 12 GPIO pins, the part can directly drive relay coils, triac interfaces, LED indicators, and 7-segment displays without external logic. The 3.0-5.5V supply range accommodates both 3.3V and 5V designs common in white goods. Built-in watchdog timer and power-on reset simplify firmware reliability for unattended consumer products. The 18-SOIC package on tape-and-reel supports high-speed pick-and-place assembly in mass-production appliance manufacturing.
Recommended
HVAC Thermostat Interfaces
Thermostat and HVAC user-interface boards benefit from the PIC16C56T-RCI/SO's small footprint and low power consumption. Its 4MHz clock rate is more than adequate for scanning keypads, driving LCD segments or character displays, and reading temperature sensors via I/O bit-banging. The 25-byte RAM supports simple state machines for schedule-based temperature control. The industrial -40C to +85C operating range handles indoor equipment environments. With OTP memory, firmware is locked at production - reducing field-reprogramming risk for high-volume thermostat OEM deployments.
Recommended
Remote Control Transmitters
Low-end infrared and RF remote controls leverage the PIC16C56T-RCI/SO's ultra-low cost, simple 33-instruction core, and small 18-SOIC package. The 4MHz internal instruction cycle supports software-based Manchester or pulse-width encoders for IR transmission protocols (RC-5, NEC, proprietary). The 12 I/O pins handle keypad scanning (4x4 matrix), IR LED drive via PWM/RC networks, and indicator LEDs. OTP memory prevents firmware cloning by competitors - a security benefit for high-volume consumer remote-control products. Low-power CMOS sleep modes extend battery life in handheld remote applications.
Recommended
Industrial Timer and Counter Modules
Industrial timer, counter, and sequencer modules deploy the PIC16C56T-RCI/SO for its deterministic 1 MIPS throughput and built-in watchdog timer. The 8-bit timer with on-chip RC oscillator provides accurate timing without external crystals in many designs. The 12 GPIO pins support digital input conditioning, optocoupler interfaces for 24V industrial signals, and relay/solenoid driver outputs. OTP memory prevents unauthorized firmware modification in factory-floor control equipment. The 18-SOIC package is compatible with hand-soldering for prototype and low-volume industrial production runs.
Recommended
Sensor Signal Conditioning Front-Ends
Simple sensor signal conditioning boards use the PIC16C56T-RCI/SO as a low-cost ADC-free microcontroller paired with external sigma-delta or dual-slope converters. The 4MHz clock supports software UART communication for sensor data logging, while 12 GPIO lines drive MUX select lines and latch control signals. The 25-byte RAM holds raw ADC samples before averaging and forwarding. OTP code protection prevents reverse-engineering of proprietary calibration algorithms. The 3.0-5.5V supply range accommodates battery and line-powered sensor nodes.
Recommended
Battery-Powered Sensor Interfaces
Battery-powered wireless sensor endpoints leverage the PIC16C56T-RCI/SO's CMOS low-power architecture and 3.0-5.5V supply range to maximize battery life. The internal RC oscillator and sleep modes support duty-cycled operation where the MCU wakes, samples, transmits, and returns to sleep within milliseconds. The 4MHz active clock enables fast processing between long sleep periods. OTP memory prevents firmware tampering for security-sensitive applications. The compact 18-SOIC package fits inside miniature sensor housings used in IoT and industrial monitoring deployments.
Recommended
Consumer Electronics User Interface
Consumer electronics user-interface boards (toys, small appliances, audio accessories) deploy the PIC16C56T-RCI/SO for button debouncing, LED pattern control, and simple buzzer tone generation. The 33-instruction RISC core handles multiple concurrent tasks via cooperative scheduling within the 1.5KB code space. The 12 GPIO pins support 4x4 keypads, RGB LED drivers, and PWM audio output via timer overflow interrupts. OTP memory secures proprietary UI/UX firmware. The 18-SOIC 7.50mm package provides a robust mechanical mount suitable for hand-assembly consumer products.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56T-RCI/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55T-RCI/SO | PIC16C56-RCI/SO | PIC16C55T-HSI/SO | PIC16C55T-LPI/SO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC (7.50 mm) | 18-SOIC - same | 18-SOIC - same | 18-SOIC - same | 18-SOIC - same |
| Program Memory | 1.5 KB (1K x 12) OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 200 kHz |
| Operating Voltage | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 2.5V to 6.0V |
| RAM | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| I/O Pins | 12 | 12 | 12 | 12 | 12 |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM |
| Packaging | Tape & Reel | Tape & Reel | Tube | Tape & Reel | Tape & Reel |
Key Differentiators
- Wide operating voltage 3.0V-5.5V supports both 3.3V and 5V rails (vs PIC16C55T-LPI/SO)
- Standard 4MHz RC-oscillator variant for cost-down crystal-less designs (vs PIC16C55T-HSI/SO)
- Tape-and-reel packaging for high-speed SMT assembly (vs PIC16C56-RCI/SO)
Design Notes
PIC16C56T-RCI/SO supply design must include a 100nF ceramic decoupling capacitor placed within 5mm of the VDD pin (pin 14), with a bulk 10uF tantalum or aluminum electrolytic capacitor at the board's power entry point. The MCU draws up to ~2mA active at 4MHz/5V; add a series ferrite bead if the supply rail is shared with switching converters to prevent digital noise injection into analog sections of the board.
Route the MCLR (pin 4) trace as short as possible and place the 10k pull-up resistor within 5mm of the MCU. For noisy industrial environments, add a 100nF capacitor and 1N4148 diode clamp on MCLR to prevent voltage transients from triggering unintended resets. The OSC1/OSC2 traces (pins 15-16) should be short and guarded with a ground plane on both sides if using a crystal oscillator.
Do not attempt to reprogram OTP memory in-circuit - it is one-time programmable and will reject further writes. Validate all firmware using a flash-based PIC16F56 or PIC16F84A equivalent before committing to OTP production. Confirm that your code-protection configuration bits are set correctly BEFORE OTP programming; once programmed, the code is permanently locked and cannot be changed. Order extra units (~10% overage) for development to allow for code-protection misconfiguration recoveries.
Compliance Information
RoHS, REACH, lead-free, and halogen-free compliance status was not present in the verified web data - [DATA_NEEDED] markers used in specs. The PIC16C56 family is not AEC-Q100 qualified; consider PIC16F or PIC18 automotive-grade variants for vehicle applications.