PIC16C55-10I/SO - 8-bit CMOS MCU, 768B OTP, 28-SOIC | Microchip
MPN: PIC16C55-10I/SO β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.67 | $1.67 |
| 10 | $1.55 | $15.50 |
| 100 | $1.42 | $142.00 |
| 500 | $1.3 | $650.00 |
| 1,000 | $1.18 | $1,180.00 |
PIC16C55-10I/SO Overview
An 8-bit CMOS microcontroller (often abbreviated 8-bit MCU) is a single-chip computer built around an 8-bit data path, integrating a CPU core, non-volatile program memory (ROM/EPROM/Flash/OTP), volatile data memory (RAM), and programmable peripherals. Within the broader semiconductor taxonomy, an MCU sits under microcontroller -> embedded processor -> digital IC -> semiconductor. The PIC16C5X architecture uses a Harvard design with separate program and data buses, a 12-bit-wide instruction word enabling high code density, and a two-level hardware stack - characteristics that made the PIC family a workhorse for cost-sensitive 8-bit designs in the 1990s and early 2000s.
Key features of the PIC16C55-10I/SO include a fixed hardware stack of two levels, seven or eight special-function hardware registers, direct/indirect/relative addressing modes for both data and instructions, an 8-bit real-time clock/counter (TMR0) with an 8-bit programmable prescaler, a Watchdog Timer (WDT) with its own on-chip RC oscillator, Power-On Reset (POR), and power-saving SLEEP mode. The "I" suffix denotes the industrial operating-temperature grade of -40C to +85C.
The architecture uses a RISC-style instruction set with only 33 single-word single-cycle instructions; combined with the 4:1 internal clock divider relative to the external oscillator, a 10 MHz crystal yields a 2.5 MIPS instruction throughput. The OTP (one-time-programmable) EPROM allows prototype and low-to-medium-volume production programming using Microchip's MPLAB PM3 or comparable device programmers.
Typical applications include consumer white goods control (washing machines, microwave ovens, coffee makers), simple sensor conditioning and display drivers, low-cost remote controls, hobbyist and education platforms, appliance user-interface replacement of discrete logic, and industrial timing/counter modules. The 28-pin SOIC footprint also makes it suitable as a drop-in upgrade path for older 8051-based designs where code density matters.
When designing with this device, plan for an external clock source or crystal on OSC1/OSC2, place a 0.1uF decoupling capacitor within 5 mm of VDD, and note that the PIC16C5X family lacks interrupts and on-chip peripherals beyond TMR0/WDT - any advanced functionality (UART, ADC, PWM) must be implemented in software or added externally. Configuration word MCLR and oscillator selection bits must be set during programming and cannot be changed in-circuit.
This page synthesizes distributor pricing, same-package drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, giving procurement and design engineers a single decision-ready reference for the PIC16C55-10I/SO.
Drop-in alternatives for PIC16C55-10I/SO β 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/SO (same form factor and footprint) β differing in Package, Program Memory Type, Mounting Type, Program Memory Size, Hardware Stack.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C55-10/SO
β Drop-Inβ In Stock
$2.49 / Unit
View Datasheet βPIC16C55T-10I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C55-10E/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16F57-I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C55-10I/SO Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit CMOS Microcontroller (MCU) |
| Series | PIC16C5X (PIC16C55 sub-family) |
| Program Memory Type | EPROM / OTP (One-Time Programmable) |
| Program Memory Size | 768 bytes (512 x 12 words) |
| Data RAM | 25 bytes |
| Instruction Width | 12-bit |
| Data Path Width | 8-bit |
| Maximum Clock Frequency | 10 MHz |
| Supply Voltage (Vdd) | 4.5 V to 5.5 V |
| Number of I/O Pins | 20 (Ports RA, RB, RC) |
| Timers | 1 x 8-bit (TMR0) with 8-bit prescaler |
| Watchdog Timer (WDT) | Yes, with on-chip RC oscillator |
| Hardware Stack | 2 levels |
| Operating Temperature | -40 C to +85 C (Industrial grade "I") |
| Package | 28-pin SOIC (SO), 7.50 mm body width |
| Mounting Type | Surface Mount |
| Oscillator Modes | RC, XT, LP, HS (configuration word) |
| RoHS Status | ROHS3 Compliant |
PIC16C55-10I/SO Pin Configuration
| Pin 1 | RA2 β Port A bit 2 (bidirectional digital I/O) |
| Pin 2 | RA3 β Port A bit 3 (bidirectional digital I/O) |
| Pin 3 | RTCC β TMR0 real-time clock/counter external clock input |
| Pin 4 | MCLR β Master Clear (reset) input, active low |
| Pin 5 | VSS β Ground reference |
| Pin 6 | RB0 β Port B bit 0 (bidirectional digital I/O) |
| Pin 7 | RB1 β Port B bit 1 (bidirectional digital I/O) |
| Pin 8 | RB2 β Port B bit 2 (bidirectional digital I/O) |
| Pin 9 | RB3 β Port B bit 3 (bidirectional digital I/O) |
| Pin 10 | RB4 β Port B bit 4 (bidirectional digital I/O) |
| Pin 11 | RB5 β Port B bit 5 (bidirectional digital I/O) |
| Pin 12 | RB6 β Port B bit 6 (bidirectional digital I/O) |
| Pin 13 | RB7 β Port B bit 7 (bidirectional digital I/O) |
| Pin 14 | VSS β Ground reference |
| Pin 15 | OSC2 β Oscillator crystal/ceramic output |
| Pin 16 | OSC1 β Oscillator crystal/ceramic input or external clock input |
| Pin 17 | VDD β Positive supply voltage (+5 V nominal) |
| Pin 18 | RC0 β Port C bit 0 (bidirectional digital I/O) |
| Pin 19 | RC1 β Port C bit 1 (bidirectional digital I/O) |
| Pin 20 | RC2 β Port C bit 2 (bidirectional digital I/O) |
| Pin 21 | RC3 β Port C bit 3 (bidirectional digital I/O) |
| Pin 22 | RC4 β Port C bit 4 (bidirectional digital I/O) |
| Pin 23 | RC5 β Port C bit 5 (bidirectional digital I/O) |
| Pin 24 | RC6 β Port C bit 6 (bidirectional digital I/O) |
| Pin 25 | RC7 β Port C bit 7 (bidirectional digital I/O) |
| Pin 26 | VSS β Ground reference |
| Pin 27 | RA0 β Port A bit 0 (bidirectional digital I/O) |
| Pin 28 | RA1 β Port A bit 1 (bidirectional digital I/O) |
Typical Applications
PIC16C55-10I/SO is suitable for 6 applications: Consumer White Goods Control, Remote Control and IR Transmitter, Sensor Conditioning and Display Driver, Industrial Timer and Counter Module, Hobbyist and Educational Platform, Legacy 8051 Logic Replacement.
Consumer White Goods Control
The PIC16C55-10I/SO is well suited to white-goods control boards (washing machines, microwave ovens, dishwashers) where its 768-byte OTP memory, 20 I/O pins, and 4.5V-5.5V supply match the simplicity of solenoid/relay/buzzer interfaces. Its industrial -40C to +85C temperature grade handles appliance under-cabinet environments with margin. A 10 MHz oscillator divided by 4 yields 2.5 MIPS, enough to scan a 4x4 keypad, drive a multiplexed LED or LCD segment display, and execute state-machine control code in tight loops. The PIC16C5X baseline core's deterministic instruction timing simplifies IEC 60730 class B safety-code review for household appliances.
Recommended
Remote Control and IR Transmitter
Handheld IR remote controls and simple RF key fobs pair naturally with the PIC16C55-10I/SO thanks to its low pin count, single 5 V supply, and TMR0-based interrupt-free timing loops that can synthesize 38 kHz / 40 kHz / 56 kHz carrier frequencies in firmware. The 25-byte RAM is sufficient to debounce a 4x4 matrix keyboard and buffer 8-16 button states, while the 768-byte OTP stores the encoding tables for NEC, RC5, or proprietary protocols. The industrial temp grade survives glove-compartment and outdoor environments, and the 28-SOIC footprint fits inside a slim AAA-battery plastic enclosure with surface-mount IR LED driver transistors on the same PCB.
Recommended
Sensor Conditioning and Display Driver
Industrial sensor-interface boards that read thermistor, RTD, or simple 4-20 mA loops often deploy a PIC16C55-10I/SO as the scan controller and LED or character-LCD driver. With 20 I/O lines, the device can multiplex a 4-digit 7-segment display plus a 4x4 keypad while still leaving pins for SPI communication to an external ADC and a UART link to a host. The 10 MHz instruction throughput is fast enough to refresh a multiplexed display at 100 Hz with no visible flicker, and the deterministic 4-clock instruction cycle simplifies closed-loop PID timing. The OTP memory locks firmware against field tampering in metering applications.
Recommended
Industrial Timer and Counter Module
Standalone industrial timer, counter, and rate-meter modules use the PIC16C55-10I/SO for its hardware TMR0 register with 8-bit programmable prescaler, which can count external events on the T0CKI pin up to 10 MHz when the part is clocked at 10 MHz. Combined with WDT for fault recovery and SLEEP mode for power-saving between events, the device fits DIN-rail timer products that need UL 508 / CE-EMC compliance. The 28-SOIC industrial temp grade survives -40C cold-start outdoor installations, and the OTP memory prevents unauthorized firmware modification in OEM-installed control panels.
Recommended
Hobbyist and Educational Platform
The PIC16C55-10I/SO is widely used in university embedded-systems courses and hobbyist 8-bit retro-projects because of its simple PIC16C5X baseline architecture: only 33 single-word single-cycle instructions, no interrupt controller, and a 2-level hardware stack make the assembly-language mental model approachable for first-time students. The 28-pin SOIC version drops into standard 0.1" SOIC-to-DIP adapter boards, and the device is supported by Microchip's MPLAB X IDE with the MPASM assembler and simulators. Its 10 MHz limit and 768-byte OTP encourage careful code-size budgeting, an excellent pedagogical exercise that mirrors 1980s-era 8051 design constraints.
Recommended
Legacy 8051 Logic Replacement
Engineers tasked with cost-down redesigns of legacy 4 MHz / 8 MHz 8051 boards often swap to a PIC16C55-10I/SO for its higher code density (2:1 compression over typical 8-bit CISC parts), integrated WDT/POR, and competitive unit cost. The 28-SOIC package is smaller than the typical 8051's 40-pin DIP, freeing PCB real estate, and the 5 V single supply matches the existing 7805-based power tree without redesign. OTP memory eliminates the need for external program-memory chips and parallel address/data buses, reducing BOM count and improving reliability in long-life industrial products.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C55-10I/SO β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55-10/SO | PIC16C55T-10I/SO | PIC16C55-10E/SO | PIC16F57-I/SO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-pin SOIC | 28-pin SOIC - same | 28-pin SOIC - same | 28-pin SOIC - same | 28-pin SOIC - same |
| Program Memory | 768 B OTP (512 x 12) | 768 B OTP | 768 B OTP | 768 B OTP | 2 KB Flash |
| RAM | 25 B | 25 B | 25 B | 25 B | 72 B |
| Max Clock | 10 MHz | 10 MHz | 10 MHz | 10 MHz | 20 MHz |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 2.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | Flash (re-programmable) |
| I/O Pins | 20 | 20 | 20 | 20 | 20 |
| Pin-to-Pin Compatible | Reference | Yes | Yes | Yes | Yes |
Key Differentiators
- Industrial -40C to +85C temperature grade (vs PIC16C55-10/SO)
- Flash-based upgrade path available in same footprint (vs PIC16F57-I/SO)
- Compact 28-SOIC surface-mount package vs CERDIP (vs PIC16C55/JW)
Design Notes
Estimated: The PIC16C55-10I/SO draws approximately 2 mA active at 5 V and 10 MHz, rising to roughly 5 mA at full I/O switching. Place a 0.1 uF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 17), and add a 10 uF bulk capacitor at the board entry point. The device has no internal POR capacitor delay beyond the standard Microchip PIC16C5X POR circuit, so verify that VDD rise time is below the datasheet's 0.05 V/ms threshold or the device may experience spurious resets.
The PIC16C5X baseline core has only a 2-level hardware stack and no interrupt controller - do not write subroutines that nest deeper than 2 calls or that depend on interrupts for real-time response. Configuration-word bits (watchdog enable, oscillator mode RC/XT/HS/LP, code-protect) are programmed once at the same time as code memory and cannot be changed in-circuit; selecting the wrong oscillator mode can render the device unable to communicate with the programmer. Use Microchip's MPLAB PM3 or PICkit 3 with the baseline device-support adapter for programming.
Keep the OSC1/OSC2 trace length under 10 mm for HS-mode crystals above 4 MHz to avoid stray capacitance that detunes the oscillator. Place a ground guard ring around the crystal and tie both crystal load capacitors' returns to the VSS pin (pin 14) closest to OSC1/OSC2 rather than a distant board ground, to prevent ground-bounce-induced jitter. For RC-oscillator mode, route the timing resistor and capacitor with short traces away from switching signals.
Compliance Information
ROHS3 compliant per ics-embedded listing. Not AEC-Q100 qualified - automotive applications should select an automotive-grade PIC16 or PIC18 part instead. Lead-free matte-tin finish confirmed.
