PIC16C55-RCI/SO - 8-bit OTP MCU, 768B, 20 I/O, SOIC-28 | Microchip
MPN: PIC16C55-RCI/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.65 | $3.65 |
| 10 | $3.2 | $32.00 |
| 100 | $2.65 | $265.00 |
| 500 | $2.2 | $1,100.00 |
| 1,000 | $1.85 | $1,850.00 |
PIC16C55-RCI/SO Overview
What is a PIC16C5X microcontroller? The PIC16C5X is Microchip's original low-cost, high-performance 8-bit fully-static RISC microcontroller family based on EPROM/OTP (one-time programmable) non-volatile memory. It uses 12-bit-wide instructions with an 8-bit data path, two-level-deep hardware stack, and direct/indirect/relative addressing modes. PIC16C5X devices sit at the foundation of the PIC16 architecture hierarchy (PIC16C5X -> PIC16CXXX -> PIC16FXXX), which has grown into the industry's broadest 8-bit microcontroller portfolio.
Key features of the PIC16C55 include 768 bytes of EPROM program memory (per the Microchip parametric listing), 24 bytes of RAM, 20 digital I/O pins, one 8-bit real-time counter (TMR0), and 12-bit instruction words. The device supports operating voltages from 3.0 V to 6.25 V (parametric) and industrial temperature range -40 °C to +85 °C. Clock rates up to 20 MHz are achievable when paired with external crystal or RC oscillator components; internal RC-oscillator compatibility enables low-BOM-count designs.
Architecturally, the PIC16C55 uses a single accumulator (W register) RISC engine with 33 single-word instructions. The two-level hardware stack limits nested subroutines but is sufficient for the small control loops typical of embedded appliances. The 8-bit TMR0 with programmable prescaler provides the timing/event foundation for the device; combined with 20 I/O pins, this makes the PIC16C55 well-suited for simple control, sensing, and timing tasks.
Typical applications include low-cost consumer appliances, white goods, toys, remote controls, sensor signal-conditioning front-ends, simple LED/keypad interface controllers, and industrial control modules where OTP memory and small footprint are acceptable. Engineers designing modern boards frequently migrate designs to PIC16F5X flash-based parts but retain the PIC16C55-RCI/SO pinout to reuse proven PCB layouts.
Design consideration: OTP EPROM cannot be reprogrammed; verify firmware with windowed or JW-package samples before committing to OTP production units. When migrating to flash, note that PIC16F55 derivatives are not always drop-in compatible — confirm pinout and SFR mapping against the Microchip compatibility chart before PCB rework.
This page consolidates distributor pricing, cross-reference alternatives drawn from the Microchip PIC16C5X family, and practical design notes not found in the standalone datasheet PDF.
Drop-in alternatives for PIC16C55-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 PIC16C55-RCI/SO (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Operating Temperature, Oscillator Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C55-RCE/SO
✅ Drop-In✓ In Stock
$4.61 / Unit
View Datasheet →PIC16C55A-20I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C55-10I/SO
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC16C558-20I/SO
✅ Drop-In✓ In Stock
$1.2 / Unit
View Datasheet →PIC16C554-04I/SO
✅ Drop-In✓ In Stock
$1.68 / Unit
View Datasheet →PIC16C55-RCI/SO Maximum Ratings & Electrical Characteristics
| Core | PIC16 8-bit RISC |
| Program Memory Type | EPROM (OTP) |
| Program Memory Size | 768 bytes |
| RAM Size | 24 bytes |
| Number of I/O Pins | 20 |
| Instruction Word Width | 12 bits |
| Data Path Width | 8 bits |
| Hardware Stack Depth | 2 levels |
| Timers | 1 x 8-bit (TMR0 with prescaler) |
| Supply Voltage Range | 3.0 V to 6.25 V |
| Maximum Clock Frequency | 20 MHz |
| Oscillator Type | RC / external clock compatible |
| Operating Temperature Range | -40 °C to +85 °C (Industrial) |
| Package | 28-SOIC (0.295", 7.50 mm width) |
| Mounting Type | Surface Mount (Gull Wing) |
| MSL Level | 1 (unlimited floor life) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| AEC-Q100 | Not qualified |
| Instruction Set | 33 single-word instructions |
PIC16C55-RCI/SO Pin Configuration
| Pin 1 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 2 | RA1 — Bidirectional I/O port A bit 1 |
| Pin 3 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 4 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 5 | MCLR — Master Clear reset input (active low) |
| Pin 6 | VSS — Ground reference |
| Pin 7 | OSC1/CLKIN — Oscillator crystal input / external clock in |
| Pin 8 | OSC2/CLKOUT — Oscillator crystal output / clock out |
| Pin 9 | RC0 — Bidirectional I/O port C bit 0 |
| Pin 10 | RC1 — Bidirectional I/O port C bit 1 |
| Pin 11 | RC2 — Bidirectional I/O port C bit 2 |
| Pin 12 | RC3 — Bidirectional I/O port C bit 3 |
| Pin 13 | RC4 — Bidirectional I/O port C bit 4 |
| Pin 14 | RC5 — Bidirectional I/O port C bit 5 |
| Pin 15 | RC6 — Bidirectional I/O port C bit 6 |
| Pin 16 | RC7 — Bidirectional I/O port C bit 7 |
| Pin 17 | VSS — Ground reference |
| Pin 18 | RB0/INT — Bidirectional I/O port B bit 0 / external interrupt |
| Pin 19 | RB1 — Bidirectional I/O port B bit 1 |
| Pin 20 | RB2 — Bidirectional I/O port B bit 2 |
| Pin 21 | RB3 — Bidirectional I/O port B bit 3 |
| Pin 22 | RB4 — Bidirectional I/O port B bit 4 |
| Pin 23 | RB5 — Bidirectional I/O port B bit 5 |
| Pin 24 | RB6 — Bidirectional I/O port B bit 6 |
| Pin 25 | RB7 — Bidirectional I/O port B bit 7 |
| Pin 26 | T0CKI — Timer0 clock input (shared with RB0 alternate function) |
| Pin 27 | VDD — Positive supply voltage |
| Pin 28 | VDD — Positive supply voltage |
Typical Applications
PIC16C55-RCI/SO is suitable for 6 applications: Consumer Appliance Control, White Goods and Washing Machine Controllers, Remote Control and IR Transmitter, Toys and Hobby Electronics, Industrial Sensor Interface Front-End, LED Display and Signage Controllers.
Consumer Appliance Control
The PIC16C55-RCI/SO suits low-cost consumer appliance control boards such as coffee makers, microwave ovens, toasters, and washing-machine user interfaces. Its 20 I/O pins drive LED indicators, 7-segment displays, and keypad scan matrices without external logic; the 768-byte OTP EPROM holds fixed control firmware (no field upgrade needed). The 3.0 V to 6.25 V supply range accommodates 5 V logic rails and battery backup, while the -40 °C to +85 °C industrial temperature grade covers under-cabinet kitchen environments.
Recommended
White Goods and Washing Machine Controllers
White goods such as washing machines, dishwashers, and dryers use the PIC16C55-RCI/SO for motor control sequencing, water-level sensing, and user interface handling. The 8-bit TMR0 timer provides cycle-timing interrupts, while the 20 I/O pins interface with solenoid drivers, triac controls, and 7-segment displays. The 768-byte OTP EPROM holds deterministic firmware that cannot be field-tampered, an IP-protection advantage in competitive appliance markets. Designers can migrate to PIC16C558-20I/SO for additional program memory when adding diagnostic features.
Recommended
Remote Control and IR Transmitter
Battery-powered IR remote controls leverage the PIC16C55-RCI/SO's low-cost RISC architecture, RC-oscillator compatibility, and 3.0 V operation for TV/STB/projector remote handsets. The TMR0 timer drives IR carrier generation (typically 38 kHz or 40 kHz), and the 20 I/O pins scan 4x4 or 5x5 keypads. At 3.0 V supply, the device draws minimal current enabling coin-cell battery life of 1+ year. The OTP EPROM prevents firmware cloning, an advantage in consumer A/V markets.
Recommended
Toys and Hobby Electronics
Toy manufacturers choose the PIC16C55-RCI/SO for battery-operated toys, educational electronics kits, and hobby-grade robotic controllers. The 20 I/O pins drive LEDs, buzzers, and small DC motor drivers; TMR0 provides PWM-like timing for sound effects and LED animation. OTP EPROM at sub-$2 unit pricing keeps BOM costs low while preventing firmware duplication by competitors. The wide 3.0 V to 6.25 V supply range accepts 2xAA, 3xAA, or 4xAA battery packs without voltage regulation.
Recommended
Industrial Sensor Interface Front-End
Industrial sensor modules use the PIC16C55-RCI/SO as a pre-processor for simple 4-20 mA loop, thermistor, or switch-debounce front-ends. The 8-bit TMR0 captures timing pulses, and the 20 I/O pins read digital sensor inputs while driving optocoupler outputs. The -40 °C to +85 °C industrial temperature grade supports factory-floor installations, while OTP EPROM ensures firmware is locked at production. For higher performance, upgrade to PIC16F54 flash for field-firmware updates.
Recommended
LED Display and Signage Controllers
LED message boards, scrolling signs, and decorative lighting controllers use the PIC16C55-RCI/SO to drive multiplexed LED matrices up to 8 rows by 12 columns. The 20 I/O pins and 8-bit TMR0 provide refresh-rate multiplexing, while the 768-byte EPROM stores font tables and message sequences. The 20 MHz clock rate enables smooth scrolling animation without flicker. The wide 3.0 V to 6.25 V supply accepts 5 V power rails commonly used in LED display systems.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C55-RCI/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55-RCE/SO | PIC16C55A-20I/SO | PIC16C55-10I/SO | PIC16C558-20I/SO | PIC16C554-04I/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 |
| Program Memory | 768 B OTP EPROM | 768 B OTP EPROM | 768 B OTP EPROM | 768 B OTP EPROM | 2 KB OTP EPROM | 768 B OTP EPROM |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 10 MHz | 20 MHz | 4 MHz |
| Temperature Grade | Industrial (-40C to +85C) | Commercial (0C to +70C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) |
| RAM Size | 24 B | 24 B | 24 B | 24 B | 72 B | 24 B |
| I/O Pins | 20 | 20 | 20 | 20 | 20 | 20 |
| Supply Voltage | 3.0 V to 6.25 V | 3.0 V to 6.25 V | 3.0 V to 6.25 V | 3.0 V to 6.25 V | 3.0 V to 6.25 V | 3.0 V to 6.25 V |
Key Differentiators
- Standard PIC16C5X core with 20 MHz RC-oscillator compatibility (vs PIC16C554-04I/SO)
- Industrial temperature grade for harsh environments (vs PIC16C55-RCE/SO)
- Larger program memory within same 28-SOIC footprint (vs PIC16C55-10I/SO)
Design Notes
PIC16C55 is OTP (one-time programmable) EPROM, not flash. Production units cannot be reprogrammed. Always verify firmware on a windowed /JW sample or a flash-based PIC16F54 prototype before committing to OTP volume. The /JW package has a quartz window for UV erasure and is essential during firmware development cycles.
Add a 0.1 µF ceramic decoupling capacitor as close as possible to the VDD pins (pin 27 and pin 28 are bonded together on this 28-SOIC). For battery-operated designs with long traces, add a 10 µF bulk capacitor at the regulator output. The PIC16C55 draws less than 2 mA at 5 V / 4 MHz, but inrush during MCLR release can cause VDD droop without adequate bulk capacitance.
Route the MCLR pin (pin 5) with a short trace and a 10 kΩ pull-up to VDD. Add a 100 nF cap from MCLR to ground to filter noise spikes that could trigger unintended resets. Keep the oscillator traces (OSC1/OSC2) short and surrounded by a ground guard ring to prevent EMI coupling into adjacent I/O lines.
The PIC16C55 has a 2-level hardware stack, which limits subroutine nesting depth to 2. Plan firmware architecture accordingly — deep call chains will silently fail. Use iterative coding patterns or hardware state machines instead of recursive subroutines. Also note that the TMR0 timer overflow generates no interrupt in base PIC16C5X devices; polling is required.
Compliance Information
RoHS compliant per Microchip product documentation. Not AEC-Q100 qualified - not intended for automotive safety-critical applications. Lead-free matte-tin finish compatible with lead-free reflow profiles up to 260C peak temperature.
