PIC16C55T-RCI/SO - 8-Bit 4MHz OTP MCU 768B | 28-SOIC | Microchip
MPN: PIC16C55T-RCI/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.65 | $76.50 |
| 100 | $6.8 | $680.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $5.45 | $5,450.00 |
PIC16C55T-RCI/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory, volatile data RAM, and configurable I/O peripherals on one die. The PIC® 16C5X family is part of the original Microchip baseline RISC architecture, which sits at the bottom of the 8-bit MCU taxonomy: PIC16C5X -> PIC16C family -> PIC16 -> 8-bit PIC microcontrollers -> Microcontrollers -> Microcontrollers and Processors -> Semiconductor. The RISC Harvard architecture separates program and data buses for predictable single-cycle instruction execution, which simplifies timing analysis in cost-sensitive embedded designs.
Key specifications of the PIC16C55T-RCI/SO include a 4MHz maximum clock rate, 768B (512 x 12) OTP program memory, 24 bytes of general-purpose RAM, 20 digital I/O pins organized into ports, an external oscillator interface, and on-chip Power-On Reset (POR) and Watchdog Timer (WDT) peripherals. The 'R' suffix indicates RC oscillator compatibility while 'C' denotes the commercial operating temperature grade and 'I' the industrial temperature range.
The device operates from a 3V to 6.25V supply, supports an operating temperature range of -40°C to +85°C, and uses the well-documented PIC16C5X 12-bit instruction set. The lack of on-chip Flash or EEPROM and the 512-word program memory reflect the family's heritage as a low-cost, OTP-based replacement for fixed-logic glue functions in volume production.
Typical applications include appliance control, simple sensor interfaces, RC-servo hobby drivers, low-end consumer electronics, and industrial control subsystems where deterministic behavior, low cost, and legacy code reuse outweigh the need for reprogrammability. The 28-SOIC footprint is compatible with hand-solder prototyping and high-volume SMT assembly lines.
When designing with this part, designers should plan for OTP programming at the contract manufacturer and add a watchdog timer reset strategy in firmware. Note that PIC16C5X devices do not support in-system programming (ICSP) in the same way as Flash-based PICs, so a parallel programmer or production-grade gang programmer is required. Designers migrating to a Flash-based part should evaluate PIC16F54 or PIC16F57 as second-source options.
This page consolidates distributor pricing, packaging details, drop-in same-package alternatives, and practical design notes for the PIC16C55T-RCI/SO that are not typically found on a single manufacturer page.
Drop-in alternatives for PIC16C55T-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 PIC16C55T-RCI/SO (same form factor and footprint) — differing in Package, Mounting Type, Oscillator Type, Program Memory Size, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesPIC16C55T-RCI/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C5X (8-bit RISC, Harvard) |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 768 B (512 x 12 words) |
| RAM Size | 24 B |
| Maximum CPU Clock | 4 MHz |
| I/O Pins | 20 |
| Supply Voltage | 3 V to 6.25 V |
| Operating Temperature | -40 °C to +85 °C (Industrial) |
| Oscillator Type | External (RC compatible) |
| On-chip Peripherals | Power-On Reset (POR), Watchdog Timer (WDT) |
| Package | 28-pin SOIC (SO) |
| Packaging | Tape and Reel (T) |
| Instruction Set Width | 12-bit |
| In-System Programming | No (requires parallel/gang programmer) |
PIC16C55T-RCI/SO Pin Configuration
| Pin 1 | RA2 — Port A I/O bit 2 |
| Pin 2 | RA3 — Port A I/O bit 3 |
| Pin 3 | RTCC — Real-Time Clock/Counter input |
| Pin 4 | MCLR — Master Clear (reset) input, active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Port B I/O bit 0 |
| Pin 7 | RB1 — Port B I/O bit 1 |
| Pin 8 | RB2 — Port B I/O bit 2 |
| Pin 9 | RB3 — Port B I/O bit 3 |
| Pin 10 | RB4 — Port B I/O bit 4 |
| Pin 11 | RB5 — Port B I/O bit 5 |
| Pin 12 | RB6 — Port B I/O bit 6 |
| Pin 13 | RB7 — Port B I/O bit 7 |
| Pin 14 | VDD — Positive supply voltage (3V to 6.25V) |
| Pin 15 | OSC2 — Oscillator output / RC connection |
| Pin 16 | OSC1 — Oscillator input / RC connection |
| Pin 17 | RC0 — Port C I/O bit 0 |
| Pin 18 | RC1 — Port C I/O bit 1 |
| Pin 19 | RC2 — Port C I/O bit 2 |
| Pin 20 | RC3 — Port C I/O bit 3 |
| Pin 21 | RC4 — Port C I/O bit 4 |
| Pin 22 | RC5 — Port C I/O bit 5 |
| Pin 23 | RC6 — Port C I/O bit 6 |
| Pin 24 | RC7 — Port C I/O bit 7 |
| Pin 25 | RA0 — Port A I/O bit 0 |
| Pin 26 | RA1 — Port A I/O bit 1 |
| Pin 27 | RA4 — Port A I/O bit 4 (open-drain on some variants) |
| Pin 28 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C55T-RCI/SO is suitable for 6 applications: White Goods and Appliance Control, RC-Servo and Hobby Robotics Drivers, Simple Sensor Interface Modules, Industrial Control Subsystems, Cost-Sensitive Consumer Electronics, Display Driver and LED Sequencer Boards.
White Goods and Appliance Control
The PIC16C55T-RCI/SO is well suited for white-goods appliance control such as washing machines, dishwashers, and microwave ovens, where its deterministic 8-bit RISC core, 4MHz instruction throughput, and 20 I/O pins are sufficient to drive relays, triacs, and key-scan matrixes. The device's on-chip Watchdog Timer (WDT) and Power-On Reset (POR) reduce BOM cost by eliminating external supervisor chips, while the 28-SOIC footprint enables automated SMT assembly at scale. Designers benefit from the mature PIC16C5X instruction set, which has decades of available example code and reference designs for temperature, motor, and timing control loops.
Recommended
RC-Servo and Hobby Robotics Drivers
The PIC16C55T-RCI/SO's 4MHz clock and 20 I/O pins make it a strong fit for low-cost RC-servo drivers and hobby robotics control boards. The 12-bit instruction set is fast enough to generate stable 50Hz servo PWM with sub-microsecond jitter using a simple timer loop, and the 768B OTP program memory holds servo-mixing logic for 4-6 channels comfortably. Industrial (-40 to +85°C) temperature grade supports outdoor robotics projects, while the 28-SOIC package fits standard through-hole-adapter PCBs.
Recommended
Simple Sensor Interface Modules
The PIC16C55T-RCI/SO can serve as a slave sensor-interface MCU in front-end modules for temperature, humidity, or contact-closure sensors feeding a host controller. With 24B of RAM and 20 I/O pins, the device handles one or two ADC-free analog sensors via RC timing, plus digital sensors through bit-banged I2C or SPI. The 3V-6.25V supply range matches battery and 5V-rail designs, and the on-chip POR/WDT eliminates external reset and supervision components.
Recommended
Industrial Control Subsystems
For industrial control subsystems such as conveyor interlocks, indicator-light controllers, and simple PLC front-ends, the PIC16C55T-RCI/SO offers deterministic interrupt handling, industrial -40°C to +85°C operation, and a long-proven PIC16C5X toolchain. The 20 I/O lines comfortably drive opto-isolated inputs and relay outputs, while the on-chip WDT protects against firmware lockups in unattended installations. Engineers benefit from the part's decades-long installed base in industrial control panels.
Recommended
Cost-Sensitive Consumer Electronics
The PIC16C55T-RCI/SO targets cost-sensitive consumer electronics - remote controls, toys, and simple user-interface boards - where unit cost dominates the BOM. The OTP program memory is acceptable for one-time-programmed high-volume SKUs where firmware field updates are not required. The 28-SOIC footprint supports high-density SMT lines, and the mature PIC16C5X assembly tools minimize firmware development cost across product variants.
Recommended
Display Driver and LED Sequencer Boards
The PIC16C55T-RCI/SO can multiplex or charlieplex 7-segment displays and LED matrices up to 20 segments per scan, making it a strong fit for low-cost price-tag displays, status indicator panels, and decorative lighting sequencers. The 4MHz core produces stable 100+ Hz refresh without flicker, while the 20 I/O pins drive transistor arrays for row/column control. Industrial temperature grade supports semi-outdoor installations such as vending machine front panels.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C55T-RCI/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55T-RC/SO | PIC16C55-RCI/SO | PIC16C55T-RCE/SO | PIC16C55T-LPI/SO | PIC16C55T-10I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Maximum Clock | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz (low-power) | 10 MHz |
| Program Memory | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) | 768 B (512 x 12) |
| RAM | 24 B | 24 B | 24 B | 24 B | 24 B | 24 B |
| I/O Pins | 20 | 20 | 20 | 20 | 20 | 20 |
| Temperature Grade | -40°C to +85°C (I) | 0°C to +70°C (commercial) | -40°C to +85°C (I) | -40°C to +125°C (E) | -40°C to +85°C (I) | -40°C to +85°C (I) |
| Oscillator Type | RC compatible | RC compatible | RC compatible | RC compatible | LP (low-power oscillator) | RC compatible |
Key Differentiators
- Industrial temperature grade (-40C to +85C) in 28-SOIC (vs PIC16C55T-RC/SO)
- Higher maximum clock ceiling when peak throughput is required (vs PIC16C55T-10I/SO)
- Extended temperature option for harsher thermal environments (vs PIC16C55T-RCE/SO)
Design Notes
The PIC16C55T-RCI/SO uses One-Time Programmable (OTP) EPROM for program memory - once programmed, the device cannot be erased or rewritten. Plan your programming flow carefully: design verification, beta firmware validation, and pilot build must all complete on UV-erasable PIC16C55 JW (windowed) prototypes before committing to OTP units. For development, use the PIC16F54-I/SO equivalent which offers Flash reprogrammability through ICSP, then port the validated firmware back to the OTP PIC16C55 for production.
Place a 100nF ceramic decoupling capacitor within 5mm of the VDD pin (pin 14) and a bulk 10uF tantalum or aluminum capacitor near the 28-SOIC supply entry. MCLR (pin 4) should be tied to VDD through a 10kohm resistor with a 100nF cap to ground for a clean power-on reset; omitting this may cause intermittent brown-out failures. Keep OSC1/OSC2 traces short and guarded with a ground ring when using crystal mode to minimize EMI pickup.
The PIC16C5X core does not include a hardware UART, so RS-232 communication requires a software bit-banged UART. Estimated: at 4MHz CPU clock, a software UART at 9600 baud with 8-N-1 consumes roughly 60% of CPU time on the RTCC interrupt, leaving limited headroom for additional processing. For production designs that need hardware serial, migrate to PIC16F628 or PIC16F88 which include a USART peripheral.
Compliance Information
RoHS, REACH, lead-free, and halogen-free status are not explicitly confirmed in the verified web data. The PIC16C5X family predates widespread RoHS adoption, so leaded finishes are common in this product line. AEC-Q100 is not applicable - the part is not automotive qualified.
