PIC16C54T-XTI/SO - 8-bit 4MHz OTP MCU, 512B EPROM | Microchip
MPN: PIC16C54T-XTI/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.62 | $16.20 |
| 100 | $1.4 | $140.00 |
| 500 | $1.22 | $610.00 |
| 1,000 | $1.05 | $1,050.00 |
PIC16C54T-XTI/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, data RAM, and peripheral I/O on one piece of silicon. The PIC16C5x family is one of the original Microchip baseline architectures, implementing a Harvard RISC core with 12-bit-wide instructions that yield approximately 2:1 code compression over competitive 8-bit CISC devices of its class. PIC16C54 sits at the entry of the PIC taxonomy: PIC16C54 -> PIC16C5x family -> PIC baseline -> 8-bit PIC -> Microcontroller -> Semiconductor. Its simple, deterministic instruction set enables compact code development and predictable real-time interrupt response.
Key features include a 4 MHz oscillator input (XT grade), 33 single-word instructions, a 12-bit instruction word, two 8-bit I/O ports (Port A and Port B, total 12 I/O pins), an 8-bit real-time clock/counter with 8-bit programmable prescaler, power-on reset, watchdog timer with on-chip RC oscillator, and code-protection EPROM. The CMOS process keeps active supply current low while supporting 3.0V to 6.25V operation (industrial variants typically 3.0V-6.25V) and offers a power-saving SLEEP mode that wakes on pin change or watchdog timeout.
The PIC16C54 architecture uses a single accumulator (W register) and a two-level hardware stack, characteristic of baseline PIC devices. The Harvard memory map separates program EPROM (512 x 12) from data RAM (25 x 8) and the 7-bit file register space. The wide 12-bit instruction word allows most instructions to execute in a single instruction cycle (4 oscillator clocks), giving an effective 1 MIPS throughput at 4 MHz - adequate for logic replacement, simple sequencer, and glue-logic consolidation duties.
Typical applications include logic replacement in appliance controls, RC servo and PWM generator firmware, simple sensor interface front-ends (with external ADC), automotive interior trim controls, security keypads, low-end consumer devices, and industrial timer/counter modules. The industrial -40C to +85C range plus wide 3.0V-6.25V supply tolerance makes it robust for 5V industrial environments. The OTP EPROM is suitable for low-to-medium volume production where the final firmware is fixed before release.
When designing with the PIC16C54T-XTI/SO, use the Microchip MPASM assembler and MPLAB SIM/MPLAB X IDE for code development, and the MPLAB PM3 universal programmer for OTP device programming. The XT oscillator mode requires a 4 MHz crystal or ceramic resonator with the appropriate load capacitors per the datasheet. For new designs, consider migrating to the flash-based PIC16F54 in the same 18-pin SOIC footprint, which offers identical peripherals and in-circuit programmability.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes that are not consolidated on a single manufacturer page.
Drop-in alternatives for PIC16C54T-XTI/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 PIC16C54T-XTI/SO (same form factor and footprint) — differing in Package, Program Memory Type, Core Architecture, Program Memory Size, Watchdog Timer.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C54T-XTI/SO
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC16C54-XTI/SO
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →PIC16C54T-LPI/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.55 / Unit
View Datasheet →PIC16C54CT-20I/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.95 / Unit
View Datasheet →PIC16C54T-RCI/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.55 / Unit
View Datasheet →PIC16C54C-04I/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.18 / Unit
View Datasheet →PIC16C54T-XTI/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (baseline) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 768 B (512 x 12) |
| Data RAM | 25 B |
| Maximum CPU Frequency | 4 MHz (XT grade) |
| Instruction Set | 33 single-word instructions, 12-bit wide |
| I/O Pins | 12 (Port A + Port B) |
| Timers | 1 x 8-bit timer/counter with 8-bit prescaler |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| Supply Voltage Range | 3.0 V to 6.25 V |
| Operating Temperature Range | -40 C to +85 C (industrial) |
| Package | 18-SOIC (0.295 in / 7.50 mm body width) |
| Mounting Type | Surface Mount |
| Programming Method | OTP (one-time-programmable via MPLAB PM3) |
| Power-Saving Mode | SLEEP mode with wake on pin change or WDT |
PIC16C54T-XTI/SO Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (bidirectional I/O) |
| Pin 2 | RA3 — Port A bit 3 (bidirectional I/O) |
| Pin 3 | RTCC — Real-time clock/counter input (also RA0) |
| Pin 4 | MCLR — Master clear reset (active low) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Port B bit 0 (interrupt on change) |
| 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 voltage (3.0V-6.25V) |
| Pin 15 | OSC2 — Oscillator output (crystal/ceramic resonator) |
| Pin 16 | OSC1 — Oscillator input (crystal/ceramic resonator) |
| Pin 17 | RA1 — Port A bit 1 |
| Pin 18 | RA0 — Port A bit 0 (also TOCKI timer input) |
Typical Applications
PIC16C54T-XTI/SO is suitable for 6 applications: Appliance Logic Replacement, Remote Control Encoder / Decoder, Sensor Signal Front-End, PWM Motor and Lighting Control, Automotive Interior Electronics, Industrial Timer and Counter Modules.
Appliance Logic Replacement
The PIC16C54T-XTI/SO excels at replacing discrete logic gates and 555-timer circuits in appliance control boards, where its 33-instruction baseline PIC core and 1 MIPS throughput at 4 MHz handle button scanning, LED multiplexing, relay sequencing, and buzzer tone generation. Its industrial -40C to +85C temperature range survives refrigerator and washing-machine environments, while the wide 3.0V-6.25V supply tolerates unregulated 5V rails. The OTP EPROM locks firmware against copying, and the 18-SOIC package fits the same footprint as legacy TTL/CMOS logic. Designers program the device using MPLAB PM3 during board-level programming, then seal firmware against field tampering.
Recommended
Remote Control Encoder / Decoder
For IR remote controls, RF key fobs, and security keypads, the PIC16C54T-XTI/SO provides just enough program memory (512 x 12) to encode Manchester, RC5, or proprietary timing protocols while staying inside a tight BOM budget. Its SLEEP mode draws microamp-level current for battery-powered transmitters, waking on RB0 interrupt to service button presses. The 4 MHz XT grade gives 1us instruction cycle granularity - sufficient for sub-millisecond IR carrier timing. OTP EPROM prevents reverse-engineering of rolling-code security algorithms. Pair with a 38 kHz IR receiver module or 433 MHz SAW resonator for complete wireless link.
Recommended
Sensor Signal Front-End
As a sensor interface front-end, the PIC16C54T-XTI/SO reads analog sensors through an external ADC (e.g., MCP3002 over SPI bit-bang) or interfaces digital sensors over one-wire or I2C protocols. Its 12 I/O pins allocate enough headroom for sensor enable, interrupt, and serial data lines while leaving room for status LEDs and a buzzer. The wide supply range (3.0V-6.25V) accommodates both 3.3V digital sensors and 5V analog front-ends. SLEEP mode with watchdog wake-up enables duty-cycled battery operation in environmental monitors. Industrial temperature grade suits HVAC and outdoor sensor enclosures.
Recommended
PWM Motor and Lighting Control
The PIC16C54T-XTI/SO generates PWM waveforms for small DC motor speed control, LED dimming, and triac-fired lamp dimmers by toggling an I/O pin in software using the 8-bit timer interrupt. At 4 MHz the instruction cycle is 1us, allowing PWM frequencies from 100 Hz to 10 kHz with 8-bit duty-cycle resolution. The OTP EPROM stores fixed lighting scenes and motor acceleration curves without field reprogramming risk. SLEEP mode reduces idle current to microamps between user-triggered events. Industrial temperature range handles automotive interior LED strip and dashboard dimming applications reliably.
Recommended
Automotive Interior Electronics
For non-safety automotive interior applications - such as HVAC mode switches, seat-position memory, dashboard illumination, and accessory timer circuits - the PIC16C54T-XTI/SO provides industrial-grade reliability at -40C to +85C in a compact 18-SOIC footprint. Its 3.0V to 6.25V supply range tolerates 12V-battery transients when paired with external regulation. Watchdog timer with on-chip RC oscillator prevents firmware lockup in electrically noisy environments. OTP EPROM locks configuration data and timing parameters. For safety-critical or AEC-Q100 applications, migrate to the PIC16F family with automotive qualification.
Recommended
Industrial Timer and Counter Modules
The PIC16C54T-XTI/SO serves as the brain of standalone industrial timers, cycle counters, and process-interval controllers where fixed firmware is acceptable. Its on-chip 8-bit timer with 8-bit prescaler supports timing intervals from microseconds to seconds when fed by the 4 MHz XT oscillator. Multiple PIC16C54 chips can be networked over GPIO bit-banged UART for distributed control, or stand alone for cost-sensitive OEM equipment. The 18-SOIC package reflow-solders onto standard SMT lines. Industrial -40C to +85C operation suits factory-floor cabinets; OTP EPROM protects proprietary timing algorithms from field duplication.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54T-XTI/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54-XTI/SO | PIC16C54T-LPI/SO | PIC16C54CT-20I/SO |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC (0.295 in) | 18-SOIC (0.295 in) - same | 18-SOIC (0.295 in) - same | 18-SOIC (0.295 in) - same |
| Program Memory | 768 B (512 x 12) OTP EPROM | 768 B (512 x 12) OTP EPROM | 768 B (512 x 12) OTP EPROM | 2 KB (approx) OTP EPROM |
| Max Oscillator Frequency | 4 MHz (XT) | 4 MHz (XT) | 32 kHz (LP) | 20 MHz |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| Supply Voltage | 3.0V to 6.25V | 3.0V to 6.25V | 3.0V to 6.25V | 3.0V to 6.25V |
| Packing Media | Tape & Reel | Tube | Tape & Reel | Tape & Reel |
| Watchdog Timer | Yes | Yes | Yes | Yes |
| Lifecycle Status | NRND | NRND | NRND | NRND |
Key Differentiators
- Industrial temperature grade with Tape & Reel packing (vs PIC16C54-XTI/SO)
- XT oscillator grade for 4 MHz crystal timing (vs PIC16C54T-LPI/SO)
- Baseline PIC core simplicity vs higher-end families (vs PIC16C54CT-20I/SO)
Design Notes
Estimated: At 4 MHz oscillator, 5V supply, and all I/O pins static, the PIC16C54T-XTI/SO draws approximately 1.7 mA active supply current per the PIC16C5x datasheet typical characteristics. In SLEEP mode current drops to under 1 uA with watchdog disabled, or roughly 5-7 uA with watchdog enabled. Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of the VDD pin (pin 14) to suppress switching transients. For battery-powered designs, gate the supply with an external P-channel MOSFET controlled by an I/O pin to achieve deep power-down states below 1 uA total system current.
The XT grade accepts a 4 MHz crystal or ceramic resonator between OSC1 (pin 16) and OSC2 (pin 15). Use load capacitors of 15-33 pF on each leg to ground, with values selected per the crystal manufacturer's CL specification. For cost-sensitive designs, an external 4 MHz CMOS clock can drive OSC1 directly while leaving OSC2 floating. Avoid routing the crystal traces near I/O switching lines; keep the oscillator loop under 5 mm trace length to prevent EMI coupling and frequency instability.
The OTP EPROM requires high-voltage programming (typically 13V on MCLR) using the Microchip MPLAB PM3 universal programmer or equivalent third-party device programmer. Production programming should occur before SMT soldering, or via in-circuit programming adapter headers if design allows. Once programmed, OTP bits cannot be erased - budget for one-time engineering parts and validate firmware on PIC16F54 (flash equivalent) before committing to OTP volume orders. Code-protect bits should be set for production to prevent firmware extraction.
Common mistakes include (1) leaving MCLR floating - tie to VDD through a 10 kohm resistor with a 100 nF decoupling cap directly at the pin; (2) exceeding the 6.25V absolute maximum VDD rating, which permanently damages the device; (3) using uninitialized RAM contents at startup - clear the file registers during initialization; (4) forgetting to enable the watchdog timer in electrically noisy environments where firmware lockup is a risk; (5) attempting to use PIC16C54 firmware on PIC16F5x without verifying register map differences - the baseline PIC core is similar but configuration bits differ between revisions.
Compliance Information
RoHS compliance status not confirmed in current distributor data as of 2026-09-16; request certificate from Microchip or distributor. Not AEC-Q100 qualified - use PIC16F family for automotive safety-critical applications.
