PIC16C54-XTI/SO - 8-Bit OTP MCU 4MHz 768B | Microchip | 18-SOIC
MPN: PIC16C54-XTI/SO β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.66 | $26.60 |
| 100 | $2.34 | $234.00 |
| 500 | $2.07 | $1,035.00 |
| 1,000 | $1.85 | $1,850.00 |
PIC16C54-XTI/SO Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, non-volatile program memory, volatile data RAM, and configurable peripheral I/O, all integrated into one IC. The PIC16C5X belongs to the PIC16 family of microcontrollers, which sits inside the broader 8-bit MCU taxonomy alongside 8051, AVR, and ST7 architectures, and serves as a foundational tier of the embedded semiconductor hierarchy (8-bit MCU -> microcontroller -> embedded processor -> semiconductor IC). The "C" suffix denotes the CMOS EPROM-based process; the "54" designates the family member with 768 bytes of OTP program memory.
Key features include 33 single-word single-cycle RISC instructions, a two-level hardware stack, direct/indirect/relative addressing modes, an 8-bit real-time clock/counter (TMR0) with 8-bit prescaler, a watchdog timer, power-on reset, and seven or eight special function hardware registers. All instructions execute in a single 250 ns instruction cycle at 4 MHz (XT oscillator), achieving approximately 4 MIPS throughput with deterministic core execution.
The device employs a Harvard architecture with a 12-bit-wide instruction word and an 8-bit-wide data path, producing a typical 2:1 code compression advantage over competing 8-bit MCUs in the same price class. The internal oscillator start-up timer and power-up timer eliminate external reset circuitry in many designs, while the wide operating voltage range supports both 3V and 5V systems. The SOIC-18 surface-mount package allows low-profile industrial assembly.
Typical applications include appliance control, LED display drivers, remote transmitters, simple sensor interfaces, battery chargers, and low-cost consumer electronics where deterministic execution and minimal external component count matter more than memory size or peripheral richness. The industrial temperature grade (-40C to +85C) extends usability to factory automation peripherals and outdoor instrumentation.
When designing with this device, ensure that the XT oscillator crystal or resonator value is matched to the application's clock accuracy requirement (4 MHz max for the "XT" designation), and add proper power-supply decoupling (0.1 uF ceramic) close to VDD. Note that OTP memory cannot be re-programmed - choose the PIC16F54 Flash variant if in-field firmware updates are required.
This page synthesizes distributor pricing, drop-in PIC16C5X family alternatives, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC16C54-XTI/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 PIC16C54-XTI/SO (same form factor and footprint) β differing in Package, Timers, Watchdog Timer, Program Memory Size, Program Memory Type.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
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Request AlternativesPIC16C54-XTI/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C5X, 8-bit RISC Harvard |
| Program Memory Size | 768 B (512 x 12) OTP EPROM |
| RAM Size | 25 B |
| Maximum CPU Frequency | 4 MHz |
| Instruction Word Width | 12-bit |
| Number of I/O Pins | 12 |
| Instruction Set Size | 33 single-word instructions |
| Hardware Stack Depth | 2 levels |
| Timers | 1 x 8-bit (TMR0) with 8-bit prescaler |
| Watchdog Timer | Yes |
| Operating Temperature Range | -40C to +85C (industrial) |
| Oscillator Type | XT crystal/resonator (4 MHz max) |
| Package | 18-pin SOIC (SOIC-18) |
| Mounting Type | Surface Mount |
| Program Memory Type | OTP (One-Time-Programmable) EPROM |
| Data EEPROM | None |
PIC16C54-XTI/SO Pin Configuration
| Pin 1 | RA2 β Port A bit 2 / VPP programming voltage |
| Pin 2 | RA3 β Port A bit 3 |
| Pin 3 | RTCC β TMR0 timer clock input (RA4) |
| Pin 4 | OSC1 β Crystal oscillator input |
| Pin 5 | OSC2 β Crystal oscillator output |
| Pin 6 | T0CKI β Timer0 external clock input |
| Pin 7 | RB0 β Port B bit 0 |
| Pin 8 | RB1 β Port B bit 1 |
| Pin 9 | RB2 β Port B bit 2 |
| Pin 10 | RB3 β Port B bit 3 |
| Pin 11 | RB4 β Port B bit 4 |
| Pin 12 | RB5 β Port B bit 5 |
| Pin 13 | RB6 β Port B bit 6 |
| Pin 14 | RB7 β Port B bit 7 |
| Pin 15 | VSS β Ground |
| Pin 16 | VDD β Positive supply voltage |
| Pin 17 | RA0 β Port A bit 0 |
| Pin 18 | RA1 β Port A bit 1 |
Typical Applications
PIC16C54-XTI/SO is suitable for 6 applications: LED String and Holiday Light Controller, IR Remote Control Transmitter, White Goods User Interface Board, Simple Sensor Interface Module, Battery Charger Controller for NiCd/NiMH Packs, Toys and Low-Cost Consumer Electronics.
LED String and Holiday Light Controller
The PIC16C54-XTI/SO is widely used as the brain of multi-channel LED string controllers and animated holiday lights, where its 12 GPIO pins map cleanly to 4-pin RGB LED strings or 12 individual channels. The 33-instruction RISC core executes PWM-software bit-banging patterns at the 4 MHz instruction rate without additional peripheral overhead, and the 768B OTP holds complete chase, fade, and color-mix sequences for typical 8 to 16 pattern sets. The deterministic 250 ns instruction cycle prevents visible flicker that plagues interpreted architectures, while the industrial -40C to +85C temperature range supports outdoor installations. Power consumption is dominated by the LED drivers; the MCU itself typically draws under 2 mA active.
Recommended
IR Remote Control Transmitter
Consumer IR remote controls for TVs, set-top boxes, and air conditioners have used the PIC16C54-XTI/SO and its PIC16C5X siblings for decades. The 8-bit TMR0 timer with 8-bit prescaler generates accurate 38 kHz / 56 kHz carrier frequencies using a single external resonator, while the 25B RAM holds the current key matrix scan and protocol state machine. The 768B OTP stores complete RC5, NEC, SIRC, or proprietary protocol encoders along with button debounce tables. The 12 I/O pins can scan a 4x4 or 4x8 key matrix without any external decoder. Low standby current extends battery life across multi-year deployments on a single CR2032 coin cell.
Recommended
White Goods User Interface Board
Washing machines, dishwashers, refrigerators, and microwave ovens integrate the PIC16C54-XTI/SO as the central controller for push-button scan, 7-segment or LED indicator drive, buzzer control, and simple timing sequences. The 12 GPIO pins support up to 4-digit 7-segment displays with multiplexing, while the watchdog timer recovers the MCU from mains-borne transients. The 4 MHz XT oscillator provides sufficient timing accuracy for minute-resolution timer functions, and the -40C to +85C industrial temperature range handles under-cabinet and garage-appliance environments. The OTP memory secures firmware against unauthorized copy, important for appliance vendor IP protection.
Recommended
Simple Sensor Interface Module
Cost-sensitive sensor interface modules for HVAC, weather stations, and industrial telemetry use the PIC16C54-XTI/SO to read digital sensors and reformat data over UART-software or PWM-software. The 8-bit TMR0 with prescaler provides accurate timing for 1-Wire bit-banging against Maxim/Dallas temperature sensors such as DS18B20, while the 768B OTP holds sensor calibration tables and linearization coefficients. Although the device has no hardware UART, a 9600 baud software UART fits within the 25B RAM and runs reliably at the 4 MHz instruction rate. The 12 GPIO pins serve multiple sensor channels and indicator LEDs simultaneously.
Recommended
Battery Charger Controller for NiCd/NiMH Packs
The PIC16C54-XTI/SO serves as a -dV/dt termination controller for simple NiCd and NiMH battery chargers in cordless phones, power tools, and consumer rechargeables. The TMR0 captures charge-cycle timing, while the 12 GPIO pins monitor battery voltage via resistive dividers, drive charge-enable MOSFETs, and indicate status via LEDs. The OTP memory encodes charge profiles per battery chemistry, and the industrial -40C to +85C range tolerates the thermal environment of in-charger operation. The deterministic core executes the peak-detection algorithm without RTOS overhead, and the small SOIC-18 footprint simplifies integration into space-constrained wall-wart chargers.
Recommended
Toys and Low-Cost Consumer Electronics
Talking dolls, sound-effect toys, electronic games, and educational gadgets have relied on the PIC16C54-XTI/SO family since the 1990s for sub-$1 BOM controllers that play pre-stored audio phrases, blink LEDs, and respond to capacitive or resistive touch pads. The 768B OTP stores compressed audio playback tables and animation state machines, and the 4 MHz instruction cycle can PWM audio through a piezo buzzer without external DAC hardware. The SOIC-18 surface-mount package is friendly to automated toy assembly lines, and the industrial temperature grade handles shipping-container thermal swings during global logistics. Volume pricing under $2 makes it cost-competitive against custom ASICs at low production runs.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54-XTI/SO β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54C-04I/SO | PIC16C54-10I/SO | PIC16F54-I/SO |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SOIC-18 | SOIC-18 - same | SOIC-18 - same | SOIC-18 - same |
| Program Memory | 768 B OTP | 768 B OTP | 768 B OTP | 768 B Flash |
| RAM | 25 B | 25 B | 25 B | 25 B |
| Max CPU Clock | 4 MHz | 4 MHz | 10 MHz | 20 MHz |
| I/O Pins | 12 | 12 | 12 | 12 |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | Flash |
| Temperature Range | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
Key Differentiators
- Industrial temperature range (-40C to +85C) in SOIC-18 (vs PIC16C54-XT/SO)
- Original PIC16C54 silicon revision for long-term availability (vs PIC16C54C-04I/SO)
- OTP memory secures firmware IP (vs PIC16F54-I/SO)
Design Notes
Estimated: At 5V VDD and 4 MHz CPU clock, the PIC16C54-XTI/SO draws approximately 1.7 mA active and 5 uA standby (watchdog disabled). Place a 0.1 uF ceramic decoupling capacitor as close as possible to VDD (pin 16) and VSS (pin 15) using a short, wide trace to minimize digital switching noise on the analog supply rail. For battery-powered designs, gate the oscillator with the XT2 pin and use the SLEEP instruction to drop standby current below 1 uA.
The 18-pin SOIC land pattern should follow IPC-7351 nominal-density guidelines: 1.27 mm pitch pads with 0.5 mm pad width and 2.0 mm pad length. Route the XT oscillator traces (OSC1 pin 4, OSC2 pin 5) on the same layer as the MCU, kept short (under 10 mm), and place the load capacitors (typically 15-33 pF for 4 MHz crystal) within 5 mm of the oscillator pins. Guard the oscillator traces with a ground pour stitched with vias on both sides to suppress EMI injection into the digital I/O lines.
Do not connect the /MCLR reset pin of a PIC16C5X to VDD directly - the PIC16C54 has internal power-on reset and does NOT expose a /MCLR pin on the 18-SOIC variant, but legacy application notes often show external RC reset circuits that are not required. Do not assume Flash-like in-system programmability: the OTP EPROM requires a 13V VPP on RA2/VPP (pin 1) for programming, supplied only by a Microchip programmer such as MPLAB PM3. Choosing the PIC16F54-I/SO is recommended for new designs needing in-field firmware updates.
Compliance Information
RoHS and lead-free status could not be confirmed from the verified distributor listings for this legacy OTP PIC16C5X part. Microchip's older OTP EPROM parts often use SnPb finish and are non-RoHS. For RoHS-compliant designs in the same footprint, prefer PIC16F54-I/SO. AEC-Q100: not qualified (industrial temp range only, not automotive Grade 0/1).
