PIC16C55-RCE/SS - 8-Bit 4MHz OTP MCU 768B 28-SSOP | Microchip
MPN: PIC16C55-RCE/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.85 | $3.85 |
| 10 | $3.46 | $34.60 |
| 100 | $2.96 | $296.00 |
| 500 | $2.61 | $1,305.00 |
| 1,000 | $2.34 | $2,340.00 |
PIC16C55-RCE/SS Overview
An 8-bit OTP microcontroller is a single-chip computer that executes a fixed program burned into non-erasable program memory at the factory. In the broader taxonomy, the PIC16C55 belongs to: microcontroller (MCU) → 8-bit MCU → RISC MCU → PIC16 family → OTP-programmed mid-range MCU → embedded controller. Unlike flash-based MCUs the OTP variant is intended for cost-sensitive, volume production runs where firmware will not be updated in the field, which makes it common in appliance control, automotive subsystems, and disposable/embedded industrial nodes.
Key features include 33 single-word instructions, a 12-bit instruction word, two 8-bit I/O ports (Port A and Port B/C depending on revision), a 4 MHz internal-external clock domain, and a programmable WDT for unattended operation. The wide 3.0 V to 6.0 V supply range (typical 5 V) and 4 MHz fOSC let the device target low-power and battery-tolerant designs.
Architecturally, the PIC16C55 uses a 14-bit instruction word decoded from a 12-bit program word, separate program and data buses, a small instruction pipeline, and direct register-mapped I/O rather than memory-mapped peripherals. This makes for deterministic cycle timing and very small interrupt latency, which is why PIC16C-series parts have remained popular for hard-real-time control loops.
Typical applications include appliance controllers (washing machines, microwave ovens), automotive lighting/relay drivers, HVAC fan and pump controllers, low-end security keypads, simple sensor interface boards, and remote/IR transmitter logic. Engineers also use the PIC16C55 in legacy industrial controls where the OTP-only, no-debug interface is preferred for IP protection.
When designing with this part, plan the OTP programming step into the production flow: parts cannot be reprogrammed in-circuit, so a programming adapter (e.g. SSOP-28 to DIP-28) is typically used for batch programming. The lack of in-circuit debug means bench prototypes are usually developed on a flash-equivalent PIC16F5x and ported to PIC16C55 for production.
This page synthesizes distributor pricing, drop-in OTP and flash alternatives, programming-adapter guidance, and practical design notes not consolidated in a single place on the manufacturer datasheet.
Drop-in alternatives for PIC16C55-RCE/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 PIC16C55-RCE/SS (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Core Architecture, Oscillator Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C55-RCI/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C55T-RCE/SS
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC16C55-LPI/SS
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC16C55-HSI/SS
✅ Drop-In✓ In Stock
$1.4 / Unit
View Datasheet →PIC16C54-RCE/SS
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC16C55-RCE/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit Harvard RISC |
| Core Family | PIC® 16C series |
| CPU Speed | 4 MHz |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 768 bytes (512 x 12) |
| RAM Size | 24 bytes |
| I/O Pins | 20 |
| Package | 28-SSOP (5.30 mm body, 0.65 mm pitch) |
| Mounting Type | Surface Mount |
| Supply Voltage | 3.0 V to 6.0 V (5 V typical) |
| Operating Temperature | -40 °C to +85 °C |
| Peripherals | Power-On Reset (POR), Watchdog Timer (WDT) |
| Instruction Set | 33 single-word instructions, 12-bit instruction width |
| MSL Level | 1 (unlimited) |
PIC16C55-RCE/SS Pin Configuration
| Pin 1 | RA2/OSC1 — Port A bit 2 / oscillator input |
| Pin 2 | RA3/OSC2 — Port A bit 3 / oscillator output |
| Pin 3 | RA4/T0CKI — Port A bit 4 / Timer0 clock input |
| Pin 4 | MCLR — Master clear reset (active low) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Port B bit 0 / external interrupt |
| Pin 7 | RB1 — Port B bit 1 |
| Pin 8 | RB2 — Port B bit 2 |
| Pin 9 | RB3 — Port B bit 3 |
| Pin 10 | RB4 — Port B bit 4 |
| Pin 11 | RB5 — Port B bit 5 |
| Pin 12 | RB6 — Port B bit 6 |
| Pin 13 | RB7 — Port B bit 7 |
| Pin 14 | VDD — Positive supply (3.0-6.0 V) |
| Pin 15 | RC0 — Port C bit 0 |
| Pin 16 | RC1 — Port C bit 1 |
| Pin 17 | RC2 — Port C bit 2 |
| Pin 18 | RC3 — Port C bit 3 |
| Pin 19 | RC4 — Port C bit 4 |
| Pin 20 | RC5 — Port C bit 5 |
| Pin 21 | RC6 — Port C bit 6 |
| Pin 22 | RC7 — Port C bit 7 |
| Pin 23 | RA0 — Port A bit 0 |
| Pin 24 | RA1 — Port A bit 1 |
| Pin 25 | NC — Not connected (per datasheet) |
| Pin 26 | NC — Not connected (per datasheet) |
| Pin 27 | NC — Not connected (per datasheet) |
| Pin 28 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C55-RCE/SS is suitable for 7 applications: Appliance Control Board, Automotive Lighting and Relay Driver, HVAC Fan and Pump Controller, Security Keypad and Access Panel, Industrial Sensor Interface Node, Remote Control / IR Transmitter Logic, Legacy Industrial Control Retrofit.
Appliance Control Board
The PIC16C55-RCE/SS fits appliance control boards such as washing machines, microwave ovens, and dishwashers because its 768-byte OTP memory holds compact state-machine firmware, the 4 MHz clock is ample for keypad debounce and relay timing, and the 20 I/O pins directly drive 7-segment displays, keypads, buzzer drivers, and TRIAC/optocoupler interfaces. The OTP-only program memory prevents field firmware theft on high-volume consumer SKUs. The commercial 0 °C to +70 °C temperature range covers indoor kitchen and laundry environments without derating. Place the device with its 28-SSOP footprint adjacent to the relay-driver PCB area; the integrated Power-On Reset eliminates the external reset IC that older 8051 designs required, lowering BOM cost.
Recommended
Automotive Lighting and Relay Driver
For automotive interior lighting, mirror controllers, and seat-adjustment relays, the PIC16C55-RCE/SS (or its industrial-grade /RCI sibling) provides deterministic 1 µs instruction cycles that handle PWM dimming and switch-debounce in real time. The wide 3.0 V to 6.0 V supply directly accommodates 5 V automotive rails with crank-cold tolerance. Its 20 I/O pins interface to MOSFET gate drivers, H-bridges, and current-sense amplifiers. The OTP program memory is suitable for fixed-function lighting controllers that ship in millions of units per platform. For under-hood applications above +70 °C, choose PIC16C55-RCI/SS instead - same 28-SSOP footprint, no firmware change required.
Recommended
HVAC Fan and Pump Controller
The PIC16C55-RCE/SS suits HVAC fan-speed controllers and small pump drivers because its 4 MHz core handles closed-loop RPM control via opto-interruptor feedback, and its 24 bytes of RAM are sufficient to track duty cycle, ramp profile, and fault counters. The integrated Watchdog Timer recovers the MCU from EMI-induced lockups in motor-noisy environments. Surface-mount SSOP packaging enables compact PCBAs that fit inside fan housings. A typical implementation uses one timer for triac phase-angle control, three I/O pins for tachometer input, and the WDT to reset on stalled-rotor faults. Pair with an MOC3021 for AC line isolation.
Recommended
Security Keypad and Access Panel
For PIN-entry keypads, RFID-access panels, and small alarm annunciators, the PIC16C55-RCE/SS offers enough program memory for rolling-code algorithms, EEPROM emulation via I/O bit-banging, and debounce of 12-button matrices. The 20 I/O pins directly scan a 4×4 keypad (8 lines) plus LEDs, buzzer, and lock-relay driver without external logic. OTP memory prevents code extraction from discarded or stolen panels, important for high-security installations. The device draws micro-amps in sleep (with WDT enabled), enabling multi-year battery life on wireless keypads. Typical implementation pairs it with a 4×4 membrane keypad and a 12 V / 500 mA door-strike relay.
Recommended
Industrial Sensor Interface Node
The PIC16C55-RCE/SS serves as a low-cost Modbus-RTU or simple polled sensor node where it reads 4-20 mA transducers, thermocouples via external amplifier, or digital switch inputs and reports results over RS-485 or RS-232. Its 4 MHz clock handles 9600 baud UART without baud-rate-generator overhead, and 24 bytes of RAM buffer short sensor read frames. The 3.0 V to 6.0 V supply matches 5 V industrial backplanes. Surface-mount SSOP allows dense PCB layout for DIN-rail modules. Designers typically pair it with an ADM485 RS-485 transceiver and a 78L05 regulator on a 24 V loop-power input.
Recommended
Remote Control / IR Transmitter Logic
The PIC16C55-RCE/SS is well-matched to consumer IR remote controls and simple RF transmitter logic because its 4 MHz core generates precise 38 kHz / 56 kHz carrier frequencies via software PWM without external timers, and its 24 bytes of RAM hold the transmit buffer and protocol state. Low sleep current with WDT extends battery life to multi-year on a CR2032 cell. OTP program memory locks the protocol against cloning - critical for proprietary garage-door and gate-operator remotes. Pair with a TSAL6200 IR LED driven through a 2N2222A transistor; the 20 I/O pins also support 4×4 button matrices and LED indicators.
Recommended
Legacy Industrial Control Retrofit
For retrofitting legacy industrial control boards that originally used the PIC16C55 in through-hole DIP, the PIC16C55-RCE/SS in 28-SSOP lets modern surface-mount assemblies drop into the same PCB layout when paired with an SSOP-to-DIP adapter (e.g. Adapt-Plus PA28SS-P55). The identical instruction set, I/O map, and register layout mean legacy firmware binaries can be re-targeted without recompile in many cases. Use this approach to extend the service life of equipment whose original PIC16C55 supply is exhausted, while maintaining identical cycle timing and WDT behavior. The /RCE commercial temperature range suits indoor control panels; choose /RCI for outdoor enclosures.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C55-RCE/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55-RCI/SS | PIC16C55T-RCE/SS | PIC16C55-LPI/SS | PIC16C55-HSI/SS | PIC16C54-RCE/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SSOP | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same |
| Program Memory | 768 B (512 × 12) OTP | 768 B (512 × 12) OTP | 768 B (512 × 12) OTP | 768 B (512 × 12) OTP | 768 B (512 × 12) OTP | 512 B (384 × 12) OTP (-33%) |
| Maximum Clock | 4 MHz (RC oscillator) | 4 MHz | 4 MHz | 4 MHz (LP osc, lower power) | 20 MHz (HS osc) | 4 MHz |
| Operating Temperature | 0 °C to +70 °C (Commercial) | -40 °C to +85 °C (Industrial) | 0 °C to +70 °C (Commercial) | -40 °C to +85 °C (Industrial) | -40 °C to +85 °C (Industrial) | 0 °C to +70 °C (Commercial) |
| I/O Pins | 20 | 20 | 20 | 20 | 20 | 20 |
| RAM | 24 B | 24 B | 24 B | 24 B | 24 B | 25 B |
| Oscillator Type | RC (Resistor-Capacitor) | RC | RC | LP (Low-Power) | HS (High-Speed) | RC |
Key Differentiators
- Wider commercial-temperature operating range vs. comparable PIC16F5x flash MCUs (vs PIC16F55-I/SS)
- Larger program memory than PIC16C54 family (vs PIC16C54-RCE/SS)
- Industrial-temperature sibling available on same footprint (vs PIC16C55-RCI/SS)
Design Notes
PIC16C55-RCE/SS OTP memory cannot be erased after programming. Always program a verified golden image, and design the firmware to default to a safe state on power-up (all outputs off). Use a programming adapter (e.g. PA28SS-P55 SSOP-to-DIP) for batch programming; the part cannot be re-programmed if the OTP image is bad.
The PIC16C55-RCE/SS operates from 3.0 V to 6.0 V; design the supply with a 100 nF decoupling capacitor within 5 mm of the VDD pin and a 10 µF bulk capacitor at the regulator output. The internal Power-On Reset holds the device in reset until VDD reaches a valid threshold - no external reset IC is needed. For battery-powered designs, use the LP oscillator variant (PIC16C55-LPI/SS) to reduce sleep current to under 4 µA.
The 28-SSOP package has a 0.65 mm pin pitch, which requires precise SMT stencil aperture design (recommend 0.4 mm aperture width) and reflow profiling to avoid tombstoning. Keep analog and digital ground returns separated and join them at a single point near the VDD bypass capacitor. The MCLR pin should be tied to VDD through a 10 kΩ resistor with a 100 nF cap to ground for clean resets during voltage transients.
At 4 MHz clock and 5 V supply the PIC16C55-RCE/SS draws approximately 2-3 mA active and <4 µA in sleep with WDT disabled. Estimated: 5 V × 3 mA = 15 mW typical dissipation in the 28-SSOP (theta-JA ~ 95 °C/W), giving a junction rise of only 1.4 °C above ambient - thermal management is not a concern. The dominant thermal risk in real designs is the output-pin source/sink current (max 20-25 mA per pin, 80 mA total) driving relays or LEDs.
Compliance Information
RoHS, REACH, lead-free, and halogen-free status were not listed in the verified distributor data and are marked unknown on this page. Microchip's legacy PIC16C OTP family is generally NOT lead-free (typical SnPb finish), but exact lot compliance must be verified against the manufacturer certificate of conformance before use in RoHS-restricted designs. AEC-Q100 not qualified - for automotive applications choose the industrial-grade /RCI suffix instead.
