PIC16C55-10I/P - 10MHz 8-Bit OTP MCU 768B 28-DIP | Microchip
MPN: PIC16C55-10I/P ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.29 | $4.29 |
| 10 | $3.86 | $38.60 |
| 100 | $3.44 | $344.00 |
| 500 | $3.01 | $1,505.00 |
| 1,000 | $2.58 | $2,580.00 |
PIC16C55-10I/P Overview
What is an OTP microcontroller? An OTP (One-Time Programmable) microcontroller is a class of MCU that uses EPROM-based non-volatile memory allowing the device to be programmed a single time using a device programmer. Unlike flash-based MCUs, OTP parts cannot be reprogrammed in-circuit and are typically chosen for cost-sensitive, high-volume production where firmware is finalized before manufacture. The PIC16C5X family uses a 12-bit wide RISC instruction set with Harvard architecture, delivering 2:1 code compression versus competing 8-bit CISC architectures in its class.
Key features include a 10 MHz maximum clock input, 33 single-word instructions, 2-level hardware stack, 8-bit timer/counter with 8-bit programmable prescaler, and power-on reset. The device integrates a watchdog timer, brown-out detection, and 20 mA sink/source capability per I/O pin. Power consumption is approximately 2 mA typical at 5V/4 MHz, making the PIC16C55-10I/P suitable for mains-powered industrial controls rather than battery applications.
Architecturally, the PIC16C55-10I/P uses a RISC Harvard design with separate program and data buses, enabling simultaneous instruction fetch and data access. The 12-bit instruction word provides direct, immediate, and relative addressing modes plus bit manipulation. The OTP program memory is windowless (one-time-only) which reduces per-unit cost versus ceramic-windowed UV-erasable variants. The -10 speed grade denotes a 10 MHz maximum oscillator frequency.
Typical applications include appliance controls, automotive body electronics, industrial sensor interfaces, and remote sensor transmitters where mature, low-cost 8-bit control is sufficient. The wide 4-6V operating range and industrial temperature rating also suit 5V industrial busses and automotive underhood environments in sealed modules.
When designing with this part, verify that your firmware volume fits within the 768-byte OTP memory budget and that you are using the PIC16C5X baseline instruction set - code written for PIC16F or PIC18 cores is not portable without rewriting. Programming requires a Microchip MPLAB PM3 or compatible device programmer; this part cannot be programmed in-circuit.
This page synthesizes distributor pricing, parametric comparison with same-family drop-in alternatives, and practical design notes not found in the manufacturer datasheet. Pricing reflects real-time distributor data and includes explicit cross-brand pin-compatibility guidance for obsolete or hard-to-source PIC16C5X inventory.
Drop-in alternatives for PIC16C55-10I/P — 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 PIC16C55-10I/P (same form factor and footprint) — differing in Watchdog Timer, Operating Temperature, Timers, Package, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C55-10/SP
✅ Drop-In✓ In Stock
$2.45 / Unit
View Datasheet →PIC16C55-HSI/P
✅ Drop-In✓ In Stock
$2.6 / Unit
View Datasheet →PIC16C54A-20I/P
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →PIC16C54-10I/P
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC16F54-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C55-10I/P Maximum Ratings & Electrical Characteristics
| Family | PIC16C5X baseline 8-bit MCU |
| Program Memory Size | 768 B (OTP EPROM) |
| RAM Size | 24 B |
| Maximum Clock Frequency | 10 MHz |
| Instruction Cycle Time | 400 ns (at 10 MHz) |
| Number of I/O Pins | 20 |
| Data Bus Width | 8 bit |
| Instruction Set Width | 12 bit |
| Supply Voltage Range | 4.0 V to 6.0 V |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Number of Timers | 1 x 8-bit (TMR0) |
| Package / Case | 28-DIP (0.600 in, 15.24 mm) |
| Mounting Type | Through-Hole |
| Watchdog Timer | Yes (WDT with on-chip RC oscillator) |
| Brown-out Reset | Yes |
| I/O Sink/Source Current | 20 mA per pin |
| Programmable Prescaler | Yes (8-bit, shared with WDT) |
| Hardware Stack | 2 levels |
| Programming Method | External device programmer (MPLAB PM3) |
PIC16C55-10I/P Pin Configuration
| Pin 1 | RA0 — Bidirectional I/O / AN0 (Port A bit 0) |
| Pin 2 | RA1 — Bidirectional I/O / AN1 (Port A bit 1) |
| Pin 3 | RA2 — Bidirectional I/O / AN2 (Port A bit 2) |
| Pin 4 | RA3 — Bidirectional I/O / AN3 (Port A bit 3) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Bidirectional I/O / external interrupt (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 | VSS — Ground reference (duplicate) |
| Pin 15 | RC0 — Bidirectional I/O (Port C bit 0) |
| Pin 16 | RC1 — Bidirectional I/O (Port C bit 1) |
| Pin 17 | RC2 — Bidirectional I/O (Port C bit 2) |
| Pin 18 | RC3 — Bidirectional I/O (Port C bit 3) |
| Pin 19 | RC4 — Bidirectional I/O (Port C bit 4) |
| Pin 20 | RC5 — Bidirectional I/O (Port C bit 5) |
| Pin 21 | RC6 — Bidirectional I/O (Port C bit 6) |
| Pin 22 | RC7 — Bidirectional I/O (Port C bit 7) |
| Pin 23 | RA4/T0CKI — Bidirectional I/O / Timer0 clock input (Port A bit 4) |
| Pin 24 | RA5/SS — Bidirectional I/O / slave select (Port A bit 5) |
| Pin 25 | VSS — Ground reference (duplicate) |
| Pin 26 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 27 | OSC1/CLKIN — Oscillator input / external clock in |
| Pin 28 | VDD — Positive supply voltage (4.0V to 6.0V) |
Typical Applications
PIC16C55-10I/P is suitable for 6 applications: Industrial Sensor Interface Controller, Appliance Control Board (Washing Machines / Dishwashers), Automotive Body Electronics (Interior Lighting / Wipers), Remote Sensor Transmitter / Wireless Encoder, Educational / Training Microcontroller Platform, Legacy Replacement / Service Inventory.
Industrial Sensor Interface Controller
The PIC16C55-10I/P fits industrial sensor interface designs that require deterministic, polled I/O at moderate speeds under harsh temperature conditions. With 20 digital I/O pins capable of 20 mA source/sink, it directly drives opto-isolated sensor inputs and relay coils without external transistors, while the 4-6V supply range and -40C to +85C industrial rating suit 5V industrial PLC backplanes. The 768-byte OTP memory holds typical sensor calibration routines (300-500 instructions), and the 8-bit TMR0 with prescaler generates precise sampling intervals. The absence of interrupts and ICSP is acceptable in factory-floor modules where firmware is finalized before deployment. Designed-in since the 1990s, the part remains common in legacy industrial controllers requiring form-fit-function replacement.
Recommended
Appliance Control Board (Washing Machines / Dishwashers)
Major home-appliance OEMs adopted the PIC16C55-10I/P for control boards in washing machines, dishwashers, and microwave ovens during the late 1990s and 2000s due to its 768-byte OTP capacity and 20 I/O count. The device drives 7-segment LED displays, mechanical relays, and rotary encoder inputs directly at 5V. The 4-6V supply range tolerates rectified mains-rail variation, and the industrial temperature grade supports under-counter and utility-room environments. The OTP memory locks firmware at production time, preventing field tampering and reducing manufacturing cost versus UV-erasable parts. The PIC16C5X 12-bit instruction set is well-suited to state-machine control of pumps, motors, and door interlocks with deterministic timing.
Recommended
Automotive Body Electronics (Interior Lighting / Wipers)
The PIC16C55-10I/P appears in automotive interior body modules including dome-light controllers, intermittent wiper timers, and seat-position memories where its 4-6V operation tolerates 12V battery transients after on-board regulation. The 20 mA per-pin drive capacity switches low-side relay coils and LED strings without driver transistors, reducing BOM cost in high-volume vehicle platforms. Its polled I/O architecture is well-matched to slow-changing switch inputs and timing-based motor control. While not AEC-Q100 qualified, the -40C to +85C industrial temperature range covers cabin and trunk environments. For underhood or safety-critical applications, Microchip recommends AEC-Q100-qualified PIC16F counterparts.
Recommended
Remote Sensor Transmitter / Wireless Encoder
Battery-powered remote sensor transmitters using the PIC16C55-10I/P leverage its low 2 mA active current and ability to drive piezo buzzers or LED indicators directly. With only 24 bytes of RAM, the device is suited to single-channel encoding applications such as garage-door openers, simple alarm transmitters, and 433 MHz OOK/ASK key-fob encoders. The PIC16C5X 12-bit core produces compact timing routines for protocol bit-banging at 1-10 kbps. Designers typically use sleep modes between transmissions, waking via the watchdog timer (1.8-second nominal period) to extend battery life. The OTP memory locks transmitter IDs at production time, preventing cloning in security applications.
Recommended
Educational / Training Microcontroller Platform
The PIC16C55-10I/P is widely used in university embedded-systems courses and self-learning kits because its PIC16C5X baseline architecture is the simplest in the PIC family with only 33 instructions and a 2-level hardware stack. The 28-DIP package is breadboard-friendly, the 5V supply is TTL-compatible, and all 20 I/O pins are accessible on through-hole pads for student wiring exercises. The OTP memory is not a drawback for teaching since each student programs a fresh chip, and the absence of interrupts reduces pedagogical complexity. Companion lab kits pair the part with LEDs, push-buttons, 7-segment displays, and a serial EEPROM to teach state machines, polling loops, and timing diagrams.
Recommended
Legacy Replacement / Service Inventory
The PIC16C55-10I/P is primarily used today as a form-fit-function replacement part for industrial controllers, building-automation systems, and appliance boards designed in the 1990s-2000s where the original firmware was written for the PIC16C5X baseline core. The Microchip product page lists the device as Obsolete but still supported for legacy customers via last-time-buy programs and distributor inventory. Service engineers specify this exact part number (including -10I/P suffix) to ensure correct temperature grade and oscillator specification. For new designs we recommend migrating to flash-based PIC16F54-I/P (same 28-DIP) or PIC16F505-I/P (more peripherals), but legacy designs with locked OTP firmware continue to depend on PIC16C55 inventory.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C55-10I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55-10/SP | PIC16C55-HSI/P | PIC16C54A-20I/P | PIC16C54-10I/P | PIC16F54-I/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-DIP (0.600 in) | 28-DIP (0.600 in) - same | 28-DIP (0.600 in) - same | 28-DIP (0.600 in) - same | 28-DIP (0.600 in) - same | 28-DIP (0.600 in) - same |
| Program Memory (bytes) | 768 | 768 - same | 768 - same | 512 (-33%) | 512 (-33%) | 512 words flash |
| Max Clock Frequency | 10 MHz | 10 MHz - same | 20 MHz (+100%) | 20 MHz (+100%) | 10 MHz - same | 20 MHz |
| Memory Type | OTP EPROM | OTP EPROM - same | OTP EPROM - same | OTP EPROM - same | OTP EPROM - same | Flash (different) |
| Operating Temperature | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| Supply Voltage Range | 4.0V to 6.0V | 4.0V to 6.0V - same | 4.0V to 6.0V - same | 2.5V to 6.0V (wider) | 4.0V to 6.0V - same | 2.0V to 5.5V (wider) |
| ICSP Support | No (external programmer only) | No - same | No - same | No - same | No - same | Yes (flash-based) |
| RAM Size (bytes) | 24 | 24 - same | 24 - same | 24 - same | 24 - same | 25 (+4%) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Active |
Key Differentiators
- Industrial temperature grade in 28-DIP package (vs PIC16C55-10/SP)
- 768 bytes OTP program memory - the largest in the PIC16C5X baseline family (vs PIC16C54-10I/P)
- Standard 10 MHz clock grade for mainstream 5V applications (vs PIC16C55-HSI/P)
Design Notes
The PIC16C55-10I/P supply range is 4.0V to 6.0V nominal; operation below 4V may cause brown-out reset during transient load dips. Add a 100 nF decoupling capacitor as close as possible to VDD (pin 28) and VSS (pin 5/14/25) to suppress switching noise. For 5V industrial environments, a 7805 LDO or DC-DC buck with at least 100 mA headroom is sufficient, since the device draws only 2-5 mA active and 1 uA standby. Estimated: input current at 10 MHz active = approximately 2.5 mA typical from datasheet typical curves.
Code written for PIC16F or PIC18 cores (mid-range and enhanced cores) does NOT run on PIC16C55-10I/P. The PIC16C5X baseline core has a different 12-bit instruction set with only 33 instructions, no interrupts, and a 2-level hardware stack (versus 8-level in mid-range PIC). When migrating existing PIC16C55 firmware to PIC16F54 for ICSP support, you must rewrite using the 14-bit mid-range instruction set - it is not source-compatible. Also note that the PIC16C5X TRIS register sets I/O direction differently than mid-range PIC16F parts.
Place the external crystal or ceramic resonator within 0.5 inches of OSC1 (pin 27) and OSC2 (pin 26) with short, symmetric traces to minimize parasitic capacitance. For RC oscillator mode (lowest cost), connect a resistor between OSC1 and VDD, and a capacitor between OSC1 and VSS, both within 0.25 inches of the pin. Keep high-current switching traces (relay coils, LED strings) away from the oscillator loop to prevent injected noise that can cause timing drift or clock glitches.
The PIC16C55-10I/P in the 28-DIP package is conservatively rated for industrial -40C to +85C operation with no special thermal management required. Power dissipation at 5V/4 MHz active is approximately 12.5 mW (5V x 2.5 mA), well below the 1 W absolute maximum. The plastic DIP package handles thermal stress adequately in standard through-hole PCB designs with normal copper pours; no heatsink is required.
Compliance Information
PIC16C55-10I/P is classified Obsolete by Microchip. RoHS, REACH, lead-free, and halogen-free compliance status was not present in the verified web data - marked [DATA_NEEDED] in specs[]. The 28-DIP through-hole package on legacy OTP devices typically uses tin-lead plating and is generally NOT RoHS compliant. For RoHS-compliant 28-DIP PIC MCUs in the same family, PIC16F54-I/P is recommended.
