PIC16C56T-RC/SS - 8-Bit 4MHz OTP MCU, 20-SSOP | Microchip
MPN: PIC16C56T-RC/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.55 | $25.50 |
| 100 | $2.18 | $218.00 |
| 500 | $1.92 | $960.00 |
| 1,000 | $1.65 | $1,650.00 |
PIC16C56T-RC/SS Overview
What is a PIC16C5X microcontroller? The PIC16C5X is a family of low-cost, high-performance, fully static 8-bit CMOS microcontrollers built on a RISC architecture. They use 12-bit-wide instructions that are highly symmetrical, achieving roughly 2:1 code compression over other 8-bit microcontrollers in their class. This family sits within the broader 8-bit MCU category alongside 8051, AVR, and PIC18, and is widely used in cost-sensitive embedded applications where simple I/O control is the primary function.
The PIC16C56T-RC/SS features 12 digital I/O pins, a Power-On Reset (POR), a Watchdog Timer (WDT), and a programmable Timer peripheral. The "RC" oscillator designator indicates an external resistor/capacitor clock configuration, providing low-cost timing for non-critical-frequency applications. The "T" suffix denotes tape-and-reel packaging for high-volume assembly, and the "/SS" suffix specifies the 20-SSOP (5.30mm body width) package.
Architecturally, the PIC16C56T-RC/SS uses a Harvard-style separate code/data bus design with a 33-instruction set, 2-level hardware stack, and direct/indirect addressing modes. The 4MHz internal clock rate yields a 1 microsecond instruction cycle, with most instructions executing in a single cycle, providing predictable real-time behavior.
Typical applications include consumer appliance controllers, simple sensor interfaces, LED driver controllers, low-end remote controls, battery chargers, and white-goods subsystems. The wide 2.0V to 6.0V operating range (per PIC16C5X family datasheet) and CMOS low-power design make it suitable for both line-powered and battery-powered products.
Design consideration: Because OTP memory cannot be re-programmed, design teams should validate firmware on a windowed (JW) or Flash-based equivalent such as PIC16F54 before committing to production. Adequate decoupling (100nF + 10uF bulk) near VDD is recommended, and the MCLR pin should be pulled high through a 10k resistor for reliable Power-On Reset.
This page synthesizes distributor pricing, pin-compatible drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C56T-RC/SS — 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-RC/SS (same form factor and footprint) — differing in Package, Program Memory Type, Core Architecture, RAM Size, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C55T-RC/SS
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.15 / Unit
View Datasheet →PIC16C56-RC/SS
✅ Drop-In✓ In Stock
$2.7 / Unit
View Datasheet →PIC16C56T-LP/SS
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.29 / Unit
View Datasheet →PIC16C56T-HSI/SS
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.41 / Unit
View Datasheet →PIC16F54-I/SS
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C56T-RC/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC |
| Family | PIC16C5X (PIC16C56) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 1.5 KB (1K x 12) |
| Data RAM | 25 bytes |
| Maximum CPU Frequency | 4 MHz |
| Instruction Cycle Time | 1 us at 4 MHz |
| I/O Pins | 12 |
| Timers | 1 x 8-bit |
| Watchdog Timer (WDT) | Yes |
| Power-On Reset (POR) | Yes |
| Oscillator Type | External RC ("RC" designator) |
| Operating Voltage Range | 2.0 V to 6.0 V |
| Operating Temperature Range | 0C to +70C (commercial) |
| Package | 20-SSOP (5.30 mm body width) |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
PIC16C56T-RC/SS 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 pin (Timer0 clock input or I/O) |
| Pin 4 | MCLR — Master Clear reset input (active low), tie to VDD through 10k |
| 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 (2.0V to 6.0V) |
| Pin 15 | OSC2 — Oscillator output (RC: 1/4 fOSC clock out) |
| Pin 16 | OSC1 — Oscillator input (external RC network on this pin for "RC" oscillator mode) |
| Pin 17 | RC0 — Bidirectional I/O port C bit 0 |
| Pin 18 | RC1 — Bidirectional I/O port C bit 1 |
| Pin 19 | RC2 — Bidirectional I/O port C bit 2 |
| Pin 20 | RC3 — Bidirectional I/O port C bit 3 |
Typical Applications
PIC16C56T-RC/SS is suitable for 7 applications: Consumer Appliance Controllers, LED Lighting Pattern Controllers, Remote Control Transmitters, Battery Chargers, White Goods Subsystems, Sensor Interface Modules, Toys and Educational Electronics.
Consumer Appliance Controllers
The PIC16C56T-RC/SS is well suited to consumer appliance controller boards (washing machines, microwave ovens, dishwashers, rice cookers) where its 1.5KB OTP program memory comfortably holds the state-machine logic for relay sequencing, sensor polling, and user-input debouncing. With 12 GPIO pins the MCU can directly drive triac outputs, read keypad matrices, and service NTC temperature sensors without external logic. The 4MHz RC oscillator is sufficient for sub-millisecond timing of relay de-bounce and PWM buzzer tones. Versus a 32-bit MCU, the PIC16C56T-RC/SS reduces BOM cost by 70-80% on the controller position while consuming only a few milliamps from a 5V rail. Pair with a ULN2003A driver for relay arrays and a single 7805 regulator.
Recommended
LED Lighting Pattern Controllers
The PIC16C56T-RC/SS drives low-end decorative LED lighting controllers - Christmas lights, signage animations, accent strips - by using its 8-bit timer to generate PWM waveforms on multiple GPIO pins simultaneously. With 12 I/O pins the MCU can control three RGB channels plus a master intensity line, or drive addressable LED clock/data pairs through bit-banged routines. The 4MHz CPU clock yields 1us instruction cycles, adequate for WS2812B timing at 800kHz or APA102 protocols. The 1.5KB OTP holds substantial animation tables and breathing-curve look-ups for several lighting modes selectable from a button input. The wide 2.0-6.0V supply range lets the part run directly from 2xAA batteries or 5V USB power.
Recommended
Remote Control Transmitters
Infrared and RF remote control transmitters benefit from the PIC16C56T-RC/SS's low cost, 12 I/O capability, and 4MHz operation. The 8-bit timer generates 38kHz carrier frequencies for IR protocols (NEC, RC5, SIRC) using PWM with interrupt-driven key scanning. The 1.5KB OTP comfortably stores multi-protocol transmit tables, manufacturer codes, and button debounce state machines. With deep-sleep via the WDT and clock-gated execution, battery life on coin cells exceeds one year in typical remote usage. The 20-SSOP package enables compact handset PCB layouts. The Watchdog Timer guards against firmware lockup during ESD events on the keypad matrix.
Recommended
Battery Chargers
Low-end NiMH and lead-acid battery chargers use the PIC16C56T-RC/SS as the charge-cycle controller. Its 12-bit instruction cycle (1us at 4MHz) is fast enough to implement delta-V detection, temperature slope termination, and timer-based safety cutoffs in firmware. The 12 GPIO pins directly interface current-sense amplifiers, MOSFET gate drivers, status LEDs, and temperature thermistors. The Watchdog Timer prevents firmware lockup that could overcharge the battery, a critical safety function. With the 2.0-6.0V supply range the MCU runs directly from the battery stack. OTP memory locks the firmware version at production, eliminating field-reprogramming risks in safety-critical charging paths.
Recommended
White Goods Subsystems
Refrigerator defrost timers, dishwasher cycle controllers, and air-conditioner louver drivers frequently use the PIC16C56T-RC/SS as a slave subsystem MCU managed by a higher-end master controller. The 1.5KB OTP holds state-machine firmware for motor sequencing, defrost timing, and alarm latching. I2C/SPI bit-banged on GPIO pins provides communication with the master without needing dedicated peripherals. The 4MHz RC oscillator eliminates external crystals, reducing the BOM cost and PCB area - significant in high-volume white goods. The industrial temperature variant operates reliably in compressor-adjacent environments. The Watchdog Timer resets the subsystem if the master stops polling, ensuring fail-safe behavior.
Recommended
Sensor Interface Modules
Industrial and consumer sensor interface modules (humidity, PIR motion, gas, distance) use the PIC16C56T-RC/SS to digitize analog sensors, perform linearization, and drive alert outputs. The 12 GPIO pins read multiple digital sensors, drive status LEDs, and toggle relay or buzzer outputs. The 8-bit timer generates precise sampling intervals for periodic sensor reads, and the WDT recovers from any firmware lockup. With 1.5KB of OTP, calibration tables and threshold logic fit comfortably. The 2.0-6.0V supply range enables direct battery operation from 2xAA or 9V cells. The CMOS low-power design extends battery life in PIR motion detectors to multi-year operation.
Recommended
Toys and Educational Electronics
Electronic toys, hobby kits, and educational platforms use the PIC16C56T-RC/SS as an inexpensive programmable controller. The 12 I/O pins drive LEDs, buzzers, simple DC motors via H-bridge, and read push buttons; the 1.5KB OTP stores behavior patterns, sound sequences, and reaction-based game logic. The 4MHz CPU executes simple PID loops for line-following robots and balance controllers in classroom settings. OTP memory locks the final firmware, preventing student tampering once the design is validated. The 20-SSOP package is breadboard-compatible with adapter PCBs, supporting both kit-form assembly and surface-mount production. The Microchip MPLAB PM3 programmer supports the PIC16C5X family for in-school programming labs.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56T-RC/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55T-RC/SS | PIC16C56-RC/SS | PIC16C56T-LP/SS | PIC16C56T-HSI/SS | PIC16F54-I/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-SSOP | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same |
| Program Memory Type | OTP EPROM (1.5KB / 1K x 12) | OTP EPROM (768B / 512 x 12) | OTP EPROM (1.5KB / 1K x 12) - identical | OTP EPROM (1.5KB / 1K x 12) - identical | OTP EPROM (1.5KB / 1K x 12) - identical | Flash (512 x 12 words) - reprogrammable |
| Data RAM | 25 bytes | 25 bytes - same | 25 bytes - same | 25 bytes - same | 25 bytes - same | 25 bytes - same |
| Maximum CPU Frequency | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz (LP oscillator) | 4 MHz (HSI oscillator) | 20 MHz (Flash variant) |
| Oscillator Type | External RC | External RC - same | External RC - same | Low-Power crystal/RC | High-Speed Internal | External RC (default) |
| I/O Pins | 12 | 12 - same | 12 - same | 12 - same | 12 - same | 12 - same |
| Memory Reprogram Cycles | 1 (OTP) | 1 (OTP) | 1 (OTP) | 1 (OTP) | 1 (OTP) | 100,000 (Flash) |
| Operating Voltage Range | 2.0 V to 6.0 V | 2.0 V to 6.0 V - same | 2.0 V to 6.0 V - same | 2.0 V to 6.0 V - same | 2.0 V to 6.0 V - same | 2.0 V to 5.5 V |
| Unit Price @ qty 1000 (USD) | 1.65 | lower (smaller die) | similar (tube packaging) | similar (LP oscillator) | similar (HSI oscillator) | higher (Flash memory) |
Key Differentiators
- Lowest-cost 1.5KB OTP MCU in PIC16C5X family with 20-SSOP (vs PIC16F54-I/SS)
- Tape-and-reel ("T" suffix) for high-volume SMT assembly (vs PIC16C56-RC/SS)
- RC oscillator eliminates external crystal cost (vs PIC16C56T-XT/SS)
Design Notes
Estimated: at 4 MHz and 5 V supply the PIC16C56T-RC/SS typically draws 2-3 mA active and <1 uA in SLEEP mode. Place a 100 nF decoupling capacitor within 5 mm of the VDD pin (pin 14) and a 10 uF bulk capacitor near the regulator output to suppress switching transients. The MCLR pin (pin 4) should be tied to VDD through a 10 kohm resistor for clean Power-On Reset; if left floating the part may enter undefined states at startup. For battery applications, use the SLEEP instruction aggressively and wake via the WDT or RTCC interrupt to extend battery life into the multi-year range.
OTP memory cannot be re-programmed. Validate firmware on a Flash-equivalent (PIC16F54-I/SS) or windowed (PIC16C56/JW) part before committing to PIC16C56T-RC/SS production programming. The "RC" oscillator provides only approximately +/-5% frequency tolerance and is unsuitable for UART baud-rate generation or precise timing - use the LP or XT variant if serial communication is required. The 12-bit PC stack allows only 2 levels of subroutine nesting; refactor deeply recursive or multi-level code into iterative state machines. The PIC16C5X does not support interrupts in the same way as PIC16F parts - interrupt handling must use the polled RTCC/WDT approach.
Keep the RC oscillator components (R and C on OSC1/OSC2) within 5 mm of pins 15-16 to minimize stray capacitance that would shift the clock frequency. Route the MCLR trace away from high-current switching nodes (relay coils, motor drivers) to prevent false resets. The 20-SSOP land pattern requires 0.65 mm pitch pads with a solder mask defined (SMD) aperture; do not use NSMD without factory process approval. Place a ground pour on the bottom layer under the MCU body for thermal dissipation and EMI shielding. Avoid running digital signal traces under the RC oscillator network.
Compliance Information
PIC16C5X family is a mature legacy product line. RoHS and lead-free status of the PIC16C56T-RC/SS specifically were not confirmed in the verified web data - check Microchip product page or PCN history for compliance details. The part is commercial temperature grade (0C to +70C), not AEC-Q100 qualified for automotive; use PIC16C56AT variants or PIC16F1xxx for AEC-Q100 applications.