PIC16C55T-RC/SS - 8-Bit 4MHz OTP MCU, 768B | Microchip
MPN: PIC16C55T-RC/SS โ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.1 | $31.00 |
| 100 | $2.78 | $278.00 |
| 500 | $2.46 | $1,230.00 |
| 1,000 | $2.15 | $2,150.00 |
PIC16C55T-RC/SS Overview
An OTP microcontroller (One-Time-Programmable) is a class of MCU that allows the user to electrically program the on-chip program memory exactly once; the bit cells use anti-fuse or fuse-link technology that cannot be erased by UV or electrical means. OTP MCUs sit in the same hierarchy as EPROM-windowed MCUs (erasable via UV light) and Flash MCUs (re-programmable many times). The PIC16C5x family specifically uses 12-bit-wide instructions, achieving a 2:1 code compression ratio over competing 8-bit architectures in its class, which reduces overall program memory footprint.
Key features include 20 bidirectional digital I/O pins, two 8-bit timer/counters, a watchdog timer, and a 4MHz maximum operating frequency with an instruction cycle time of 1ยตs. The wide supply voltage range of 4.5V to 5.5V supports industrial and consumer 5V rails. The PIC RISC core executes most instructions in a single cycle, delivering high throughput for the device class.
Technically, the PIC16C5x architecture employs a Harvard design with separate program and data buses, and 32 bytes of register-based RAM mapped as general-purpose and special-function registers. The device is fabricated in CMOS technology, offering low power consumption suitable for battery and line-powered applications. The 28-SSOP package exposes 20 usable I/O lines via two 8-bit ports plus partial port bits.
Typical applications include simple motor controls, sensor interface boards, low-end consumer appliances, LED display drivers, and educational/prototyping platforms. The 12-bit instruction set is widely documented and supported by a mature toolchain (MPASM assembler, MPLAB IDE), simplifying firmware development for engineers familiar with the PIC architecture.
When designing with this device, note that OTP memory cannot be re-programmed โ firmware must be fully validated in a windowed EPROM equivalent (e.g., PIC16C55-JW) before committing to the OTP version. Use the lowest available voltage variation for brown-out-sensitive designs and ensure the RC oscillator tolerance meets timing requirements.
This page synthesizes distributor pricing snapshots, drop-in same-family alternatives, and practical design considerations that supplement the Microchip datasheet. Information current as of 2026-09-16.
Drop-in alternatives for PIC16C55T-RC/SS โ 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-RC/SS (same form factor and footprint) โ differing in Program Memory Size, Package, Program Memory Type, Core Architecture, Maximum CPU Frequency.
Quick Comparison Tool โ Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesPIC16C55T-RC/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 768 B (512 x 12) |
| RAM Size | 24 B |
| Maximum CPU Frequency | 4 MHz |
| Instruction Cycle Time | 1 ยตs |
| Data Bus Width | 8-bit |
| Program Bus Width | 12-bit |
| I/O Pins | 20 |
| Timers/Counters | 2 x 8-bit |
| Watchdog Timer | Yes |
| Supply Voltage Range | 4.5 V to 5.5 V |
| Package | 28-SSOP (5.30 mm) |
| Mounting Type | Surface Mount |
| Oscillator Mode | RC (resistor-capacitor) |
PIC16C55T-RC/SS Pin Configuration
| Pin 1 | RA2 โ Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 โ Bidirectional I/O port A bit 3 |
| Pin 3 | RA4/T0CKI โ Bidirectional I/O port A bit 4 / Timer 0 clock input |
| Pin 4 | MCLR โ Master Clear (reset) input, active low |
| Pin 5 | VSS โ Ground reference |
| Pin 6 | RB0/INT โ Bidirectional I/O port B bit 0 / External interrupt |
| Pin 7 | RB1 โ Bidirectional I/O port B bit 1 |
| Pin 8 | RB2 โ Bidirectional I/O port B bit 2 |
| Pin 9 | RB3 โ Bidirectional I/O port B bit 3 |
| Pin 10 | RB4 โ Bidirectional I/O port B bit 4 |
| Pin 11 | RB5 โ Bidirectional I/O port B bit 5 |
| Pin 12 | RB6 โ Bidirectional I/O port B bit 6 |
| Pin 13 | RB7 โ Bidirectional I/O port B bit 7 |
| Pin 14 | VSS โ Ground reference |
| Pin 15 | OSC2 โ Oscillator output (RC mode: RCout) |
| Pin 16 | OSC1 โ Oscillator input (RC mode: Rcin) |
| Pin 17 | RC0 โ Bidirectional I/O port C bit 0 |
| Pin 18 | RC1 โ Bidirectional I/O port C bit 1 |
| Pin 19 | RC2 โ Bidirectional I/O port C bit 2 |
| Pin 20 | RC3 โ Bidirectional I/O port C bit 3 |
| Pin 21 | RC4 โ Bidirectional I/O port C bit 4 |
| Pin 22 | RC5 โ Bidirectional I/O port C bit 5 |
| Pin 23 | RC6 โ Bidirectional I/O port C bit 6 |
| Pin 24 | RC7 โ Bidirectional I/O port C bit 7 |
| Pin 25 | VSS โ Ground reference |
| Pin 26 | VDD โ Positive supply voltage (+5V) |
| Pin 27 | RA0 โ Bidirectional I/O port A bit 0 |
| Pin 28 | RA1 โ Bidirectional I/O port A bit 1 |
Typical Applications
PIC16C55T-RC/SS is suitable for 6 applications: Low-Cost DC Motor Control, Sensor Interface & Signal Conditioning Front-End, Consumer Appliance Control (White Goods), LED Display Drivers & Lighting Controllers, Educational & Prototyping Platforms, Automotive Aftermarket Accessories (Non-Safety).
Low-Cost DC Motor Control
The PIC16C55T-RC/SS drives small brushed DC motors, solenoids, and stepper indexers in cost-engineered designs. Its two 8-bit timer/counters generate PWM and direction-control signals on 20 I/O pins, while the 4MHz instruction cycle provides sufficient throughput for trapezoidal commutation at moderate speeds. A typical circuit uses one timer for PWM and a few I/O lines for H-bridge enable/logic inputs, with the 24B RAM sufficient for simple state machines. The OTP memory is well-matched to sealed motor controllers where firmware is finalized before programming, and the 4.5Vโ5.5V supply range aligns with 5V motor-driver rails. This combination delivers a BOM cost under $4 at qty 100 for the MCU plus driver.
Recommended
Sensor Interface & Signal Conditioning Front-End
The PIC16C55T-RC/SS reads analog sensors via external ADC front-ends or simple comparator inputs and pre-processes the data before forwarding it to a host controller. Its 20 I/O pins connect to multiple digital sensors (Hall effect, thermistor bridges, optical encoders) orbit, while the 4MHz core executes linearization and threshold logic at 1ยตs per instruction. The 24B RAM holds a few 16-bit sensor values and a small scratch buffer. Designers benefit from Microchip's stable PIC16C5x toolchain (MPASM, MPLAB SIM) for firmware validation. The 28-SSOP package is footprint-compatible with newer PIC16F replacement MCUs, easing future migration to Flash devices when firmware updates become necessary.
Recommended
Consumer Appliance Control (White Goods)
The PIC16C55T-RC/SS powers user-interface and timing functions in appliances such as coffee makers, microwaves, washing machines, and rice cookers, where the 20 I/O pins drive keypads, LED indicators, seven-segment displays, and relay coils. The OTP memory is acceptable because appliance firmware is rarely updated in the field, and the unit price under $3 at volume keeps BOM costs low. The 4MHz instruction cycle handles keypad scanning, debouncing, and timer-based cooking profiles. Two 8-bit timers independently track cooking duration and buzzer/relay PWM. The 28-SSOP surface-mount package is compatible with high-volume SMT assembly lines, which is essential for white-goods manufacturing.
Recommended
LED Display Drivers & Lighting Controllers
The PIC16C55T-RC/SS drives multiplexed LED matrices, seven-segment displays, and RGB lighting strips in cost-driven signage and decorative lighting. With 20 I/O lines, it can scan up to an 8x8 LED matrix using charlieplexing or directly drive 4-6 seven-segment digits via BCD decoders. The 4MHz core is sufficient for refresh rates above 100Hz, eliminating visible flicker. The OTP memory locks the lighting pattern at production time, preventing unauthorized firmware cloning โ useful for branded lighting products. The 5V supply range aligns with most LED-driver ICs, simplifying power architecture. Designers often pair it with constant-current LED drivers (e.g., MBI5024) for high-channel-count installations.
Recommended
Educational & Prototyping Platforms
The PIC16C55T-RC/SS is used in university embedded-systems courses and hobbyist projects because of its simple 12-bit instruction set, mature documentation, and availability of low-cost programmer tools (e.g., PICSTART, MPLAB Snap). The 4MHz instruction cycle and 768B program memory constrain students to efficient coding practices, reinforcing RISC fundamentals. Its 20 I/O pins are sufficient for typical lab exercises: blinking LEDs, reading switches, driving seven-segment displays, and serial UART bit-banging. The 28-SSOP variant teaches surface-mount soldering, and the PIC16C5x toolchain (MPASM assembler) remains free and widely supported. After validation, students can migrate firmware to a windowed PIC16C55-JW for further iteration or to a PIC16F Flash device.
Recommended
Automotive Aftermarket Accessories (Non-Safety)
In non-safety automotive aftermarket modules โ LED accent lighting controllers, auxiliary gauge drivers, simple alarm interfaces โ the PIC16C55T-RC/SS provides a low-cost MCU for logic and timing functions. While not AEC-Q100 qualified for OEM safety-critical use, it is widely deployed in non-critical accessories where its 4.5Vโ5.5V supply matches 5V regulators and 20 I/O lines drive LEDs, relays, and analog gauges. The OTP memory prevents post-production firmware tampering, which is valued in some aftermarket security applications. The 28-SSOP package withstands automotive under-hood and cabin thermal environments when paired with adequate PCB copper area. For OEM safety-critical ECUs, prefer AEC-Q100-qualified PIC16F or PIC18 devices.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C55T-RC/SS โ comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55-RCE/SS | PIC16C55-10I/SS | PIC16C55-HSI/SS | PIC16C55A-20I/SS | PIC16F648A-I/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SSOP | 28-SSOP | 28-SSOP | 28-SSOP | 28-SSOP | 28-SSOP |
| Core Architecture | 8-bit PIC (12-bit instructions) | 8-bit PIC (12-bit) | 8-bit PIC (12-bit) | 8-bit PIC (12-bit) | 8-bit PIC (12-bit) | 8-bit PIC (14-bit) |
| Maximum CPU Frequency | 4 MHz | 4 MHz | 10 MHz | 4 MHz | 20 MHz | 20 MHz |
| Program Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | Flash (reprogrammable) |
| Program Memory Size | 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) | 7 KB (4096 x 14) |
| I/O Pins | 20 | 20 | 20 | 20 | 20 | 16 |
| Supply Voltage | 4.5 V - 5.5 V | 4.5 V - 5.5 V | 4.5 V - 5.5 V | 4.5 V - 5.5 V | 3.0 V - 6.0 V | 2.0 V - 5.5 V |
| Reprogrammable | No (OTP) | No (OTP) | No (OTP) | No (OTP) | No (OTP) | Yes (Flash) |
Key Differentiators
- Lowest cost 28-SSOP 12-bit PIC in the family (vs PIC16F648A-I/SS)
- True 4MHz spec match for low-speed designs (vs PIC16C55-10I/SS)
- Same-die cost-optimized OTP die vs Flash die (vs PIC16C55A-20I/SS)
Design Notes
PIC16C55T-RC/SS uses OTP (One-Time-Programmable) memory โ once programmed, the firmware cannot be changed. Estimated: always validate firmware on a windowed EPROM equivalent (e.g., PIC16C55-JW) before committing to the OTP variant in production. Attempting to erase OTP with UV light will not work; bit cells use fuse technology rather than floating-gate EPROM transistors.
Decouple VDD with a 100nF ceramic capacitor placed within 5mm of the VDD pin (pin 26) and a 10ยตF bulk capacitor at the PCB power entry. The PIC16C5x family is sensitive to VDD noise during flash programming and MCLR transitions; inadequate decoupling can cause erratic resets or programming failures. Estimated: keep digital switching traces (relay drivers, LED PWM) at least 10mm from the VDD/VSS pair to minimize coupling.
Ensure the MCLR reset circuit uses a 10kฮฉ pull-up to VDD and a 100nF capacitor to ground for proper power-on reset timing per Microchip PIC16C5x datasheet recommendations. Avoid leaving MCLR floating, which can cause spurious resets in noisy environments. The 28-SSOP package exposes MCLR on pin 4; verify schematic connection before PCB layout.
PIC16C55T-RC/SS CMOS power dissipation is typically <50mW at 4MHz across the 4.5V-5.5V supply range, so the 28-SSOP package (theta-JA ~95ยฐC/W) requires no heatsink in normal operation. Estimated: at 25ยฐC ambient, full-load operation stays well within the -40ยฐC to +85ยฐC industrial temperature range with no thermal relief copper required. For sealed enclosures above 60ยฐC ambient, provide minimum 100 mmยฒ of copper pour on VDD/VSS.
Compliance Information
RoHS / REACH / lead-free status not explicitly listed in the verified web data. AEC-Q100 not qualified โ the PIC16C5x family is targeted at industrial / consumer markets, not automotive safety-critical use. Conflict-minerals compliance per Microchip's standard corporate policy.
