PIC16C54-XT/SO - 4MHz 8-Bit OTP MCU 768B | Microchip
MPN: PIC16C54-XT/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.34 | $1.34 |
| 10 | $1.21 | $12.10 |
| 100 | $1.08 | $108.00 |
| 500 | $0.95 | $475.00 |
| 1,000 | $0.84 | $840.00 |
PIC16C54-XT/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that combines a CPU, RAM, program memory, and I/O peripherals. It sits within the broader hierarchy of microcontrollers -> embedded processors -> semiconductors, and the PIC16C5x specifically uses a 12-bit wide instruction word that delivers 2:1 code compression over competing 8-bit MCUs in the same price category, meaning more functional code fits into the same program-memory footprint.
Key features include 12-bit-wide instructions with an 8-bit data path, seven special-function hardware registers, a two-level deep hardware stack, and direct, indirect, and relative addressing modes for both data and instructions. The device also integrates an 8-bit real-time clock/counter (TMR0) with a programmable prescaler, a watchdog timer for unattended operation, and brown-out / power-on reset protection. The XT suffix designates a 4 MHz crystal/ceramic-resonator oscillator option, while the /SO suffix denotes the 18-pin SOIC surface-mount package.
Architecturally, the PIC16C54-XT/SO employs a Harvard RISC core with a single-cycle instruction set (except for program branches, which take two cycles), enabling deterministic instruction timing for real-time control. The OTP program memory allows one-time field programming - ideal for mature production designs that no longer need firmware updates - while its CMOS process delivers low power consumption across the commercial operating range.
Typical applications include appliance controllers, simple sensor interfaces, LED driving circuits, keyboard scanners, low-end consumer electronics, and replacement of discrete logic in glue-logic consolidation designs. The wide operating voltage range also supports 5V regulated industrial systems.
When designing with this part, note that the OTP memory cannot be reprogrammed, so firmware must be fully validated before burning. An OTP-to-Flash migration path to PIC16F54 is recommended for new designs requiring in-field firmware updates.
This page synthesizes current distributor stock and pricing, pin-compatible drop-in alternatives within the PIC16C5x family, and practical design notes not aggregated in the manufacturer datasheet, helping engineers make faster sourcing and design decisions.
Drop-in alternatives for PIC16C54-XT/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 PIC16C54-XT/SO (same form factor and footprint) — differing in Program Memory Size, Program Memory Type, Package, Operating Temperature, Watchdog Timer.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C54C-04/SO
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →PIC16C54C-04I/SO
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →PIC16C54C-20I/SO
✅ Drop-In✓ In Stock
$1.15 / Unit
View Datasheet →PIC16C54A-04/SO
✅ Drop-In✓ In Stock
$1.4 / Unit
View Datasheet →PIC16C54A-20I/SO
✅ Drop-In✓ In Stock
$1.15 / Unit
View Datasheet →PIC16C54-RC/SO
✅ Drop-In✓ In Stock
$2.74 / Unit
View Datasheet →PIC16C54-XT/SO Maximum Ratings & Electrical Characteristics
| Product Series | PIC16C5x |
| Core Architecture | 8-bit RISC Harvard |
| Program Memory Type | OTP (One-Time Programmable) ROM |
| Program Memory Size | 768 bytes (512 x 12-bit words) |
| RAM Size | 25 bytes |
| Maximum CPU Frequency | 4 MHz |
| Instruction Width | 12-bit |
| Data Path Width | 8-bit |
| I/O Pins | 12 |
| Hardware Stack Depth | 2 levels |
| Timers | 1 x 8-bit TMR0 with prescaler |
| Watchdog Timer | Yes |
| Oscillator Type | XT (Crystal/Ceramic Resonator, 4 MHz) |
| Package | 18-SOIC (0.295 inch / 7.50 mm width) |
| Mounting Type | Surface Mount |
PIC16C54-XT/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 3 | RTCC — TMR0 real-time clock/counter input |
| Pin 4 | MCLR — Master clear (reset) input, active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Bidirectional I/O 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 | RA1/OSC2 — I/O port A bit 1 / crystal oscillator output |
| Pin 10 | RA0/OSC1 — I/O port A bit 0 / crystal oscillator input |
| Pin 11 | RA4 — Bidirectional I/O port A bit 4 |
| Pin 12 | RB3 — Bidirectional I/O port B bit 3 |
| Pin 13 | RB4 — Bidirectional I/O port B bit 4 |
| Pin 14 | RB5 — Bidirectional I/O port B bit 5 |
| Pin 15 | RB6 — Bidirectional I/O port B bit 6 |
| Pin 16 | RB7 — Bidirectional I/O port B bit 7 |
| Pin 17 | RA5 — Bidirectional I/O port A bit 5 |
| Pin 18 | VDD — Positive supply voltage |
Typical Applications
PIC16C54-XT/SO is suitable for 7 applications: Appliance Control Boards, LED Display Drivers, Keyboard and Keypad Scanners, Sensor Interface Modules, Glue-Logic Replacement, Toy and Hobby Electronics, Industrial Timer and Relay Controllers.
Appliance Control Boards
The PIC16C54-XT/SO's 12-bit RISC architecture and 25-byte RAM suit simple appliance controllers - washing machine timer boards, microwave keypads, and rice cooker control panels. Its 4 MHz throughput is sufficient for relay sequencing, LED indicator driving, and switch-matrix scanning. The OTP memory reduces per-unit cost versus Flash MCUs at high volume, and the 12 I/O pins map directly to the typical 8-key keypad plus 4-output relay cluster. The 18-SOIC package enables single-sided PCB assembly.
Recommended
LED Display Drivers
The PIC16C54-XT/SO drives multiplexed 7-segment LED displays and simple dot-matrix indicators by sequentially strobing digit lines while sourcing segment data. Its 12 I/O pins can drive a 4-digit 7-segment display directly via external transistors, and the 4 MHz instruction rate yields flicker-free refresh at 100+ Hz. The OTP memory stores lookup tables for character fonts. Brown-out reset prevents LED flicker during low-voltage transients, important for automotive and industrial displays.
Recommended
Keyboard and Keypad Scanners
The PIC16C54-XT/SO scans 4x4 or smaller key matrices by row-column scanning, debouncing each key in firmware. Its 25-byte RAM buffers up to 8 keystrokes, and 768 bytes OTP holds the scan/debounce algorithm plus serial protocol. The TMR0 counter provides 10 ms scan timing at 4 MHz, and the watchdog timer recovers from ESD-induced firmware lockups. Power-on reset ensures clean startup after battery replacement in remote controls and security panels.
Recommended
Sensor Interface Modules
The PIC16C54-XT/SO reads analog sensors via external ADC and processes digital sensors like temperature probes and humidity sensors in low-cost IoT edge nodes. Its 4 MHz throughput supports 10 Hz sensor sampling with averaging, and 25-byte RAM holds 8-sample moving averages. The 12 I/O pins interface I2C/SPI sensors and UART outputs to a host MCU. OTP memory locks the calibration coefficients, preventing field tampering in metrology applications.
Recommended
Glue-Logic Replacement
The PIC16C54-XT/SO consolidates 4-6 discrete TTL/CMOS logic chips - counters, decoders, state machines - into a single MCU, reducing PCB area and BOM cost. A typical glue-logic replacement uses 200-400 bytes of the 768-byte OTP to encode the state machine, freeing board space for additional features. The 12 I/O pins map directly to legacy logic signal paths, and the 4 MHz clock handles MHz-rate signal processing. Migration from discrete logic cuts quiescent current by 80%.
Recommended
Toy and Hobby Electronics
The PIC16C54-XT/SO powers cost-sensitive toy controllers - RC car receivers, talking dolls, and electronic games - where the 12-bit RISC core executes sound effects, motor control, and LED patterns within 768 bytes. Its 4 MHz speed drives PWM motor control at 1 kHz update rate, and 12 I/O pins interface buttons, speakers, and motor drivers. The OTP memory locks game logic against copying, and the 18-SOIC package withstands hand-soldering for hobby kits.
Recommended
Industrial Timer and Relay Controllers
The PIC16C54-XT/SO sequences industrial relays, pumps, and heaters in timer-based control panels where deterministic instruction timing is critical. Its 1 MIPS throughput at 4 MHz runs 1 ms control loops with margin, and 12 I/O drives up to 12 relay coils via drivers. The watchdog timer recovers from EMI-induced lockups, important in motor-control environments. Brown-out reset prevents chattering relays during brown-out events, and the OTP memory locks calibration in metering equipment.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54-XT/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54C-04/SO | PIC16C54C-04I/SO | PIC16C54C-20I/SO | PIC16C54A-04/SO | PIC16C54-RC/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC | 18-SOIC (same) | 18-SOIC (same) | 18-SOIC (same) | 18-SOIC (same) | 18-SOIC (same) |
| Maximum CPU Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 4 MHz | 4 MHz (RC osc) |
| Program Memory | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP |
| RAM Size | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| Oscillator Type | XT (Crystal 4 MHz) | XT/HS/RC/LP | XT/HS/RC/LP | XT/HS/RC/LP | XT/HS/RC/LP | RC oscillator |
| Temperature Grade | Commercial | Commercial | Industrial | Industrial | Commercial | Commercial |
Key Differentiators
- Industry-standard 4 MHz XT crystal oscillator (vs PIC16C54-RC/SO)
- Original base PIC16C5x family silicon (vs PIC16C54A-04/SO)
- 4 MHz speed grade matches XT crystal requirement (vs PIC16C54C-20I/SO)
Design Notes
The PIC16C54-XT/SO uses OTP (one-time programmable) memory - firmware cannot be reprogrammed or updated after the initial programming cycle. Ensure firmware is fully validated on a windowed (JW) or Flash-based PIC16F54 prototype before committing to OTP production programming. Estimated: a typical OTP programming cycle takes 5-10 seconds per device at production volume.
The XT oscillator option requires an external crystal or ceramic resonator with load capacitors typically 15-33 pF on each oscillator pin (OSC1/OSC2). For 4 MHz operation, use AT-cut fundamental-mode crystals with less than 100 ohm ESR. Place the crystal within 10 mm of the OSC1/OSC2 pins to minimize parasitic capacitance. Estimated: stray capacitance above 10 pF can shift the oscillator frequency by 0.1-0.5%.
The 18-SOIC package has 7.50 mm body width with 1.27 mm pin pitch - typical SOIC land patterns are JEDEC-standard. Apply a ground plane beneath the MCU and keep MCLR traces short to prevent false resets from noise coupling. The MCLR pin requires a 10 kohm pull-up to VDD and optionally a 0.1 uF decoupling capacitor for high-noise environments. Estimated: a 1 inch MCLR trace picks up 2-5 pF of parasitic capacitance.
Compliance Information
RoHS, REACH, lead-free, halogen-free, and conflict-mineral status not explicitly stated in the verified web data for this legacy OTP part - set to unknown pending manufacturer datasheet check. AEC-Q100 is not applicable as PIC16C54 is not an automotive-grade qualified part.
