PIC16C54A-04I/SO - 8-bit 4MHz 768B OTP MCU SOIC-18 | Microchip
MPN: PIC16C54A-04I/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.91 | $3.91 |
| 10 | $3.55 | $35.50 |
| 100 | $3.18 | $318.00 |
| 500 | $2.85 | $1,425.00 |
| 1,000 | $2.55 | $2,550.00 |
PIC16C54A-04I/SO Overview
Background: An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory (ROM/Flash/OTP), data RAM, and peripheral I/O on one die. PIC microcontrollers use a RISC (Reduced Instruction Set Computer) architecture with a Harvard memory layout that separates program and data buses. The PIC16C5X series is one of Microchip's oldest and most cost-optimized families, designed for high-volume, cost-sensitive embedded control. OTP memory allows the user to program the device once with a low-cost EPROM writer, while the 12-bit wide instruction word gives 2:1 code compression compared with 8-bit CISC MCUs of the same era.
Key features include 12-bit wide instructions, 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 part also integrates an 8-bit real-time clock/counter (TMR0) and offers a 4 MHz maximum operating frequency, 12 digital I/O pins, and an instruction cycle time of four oscillator clocks. The device operates from a 4.5 V to 5.5 V single supply.
Architecturally, the PIC16C54A implements a fully static CMOS core so the clock can be stopped without losing register state, and its symmetric instruction set is optimized for one-cycle execution except for branch instructions which take two cycles. The 12-bit instruction width delivers denser code than typical 8-bit MCUs of the same generation, allowing the small 512-word OTP program space to host meaningful applications.
Typical applications include low-cost consumer appliances, hobbyist and educational projects, simple LED controllers, small white-goods control boards, and battery chargers where minimal logic and very low unit cost are required. The device is also used as a glue-logic replacement for discrete timer/sequencer circuits and as an introduction MCU for embedded training.
When designing with the PIC16C54A-04I/SO, use the industrial temperature grade (I suffix) to ensure operation from -40 °C to +85 °C, and note that OTP memory cannot be reprogrammed in-circuit - a flash-based PIC16F54 should be considered for prototyping. Decoupling caps of 100 nF plus 10 µF close to VDD are required for stable operation.
This page synthesizes Microchip distributor pricing, verified drop-in alternatives within the same PIC16C5X family, and practical design notes that are not consolidated in any single manufacturer document.
Drop-in alternatives for PIC16C54A-04I/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 PIC16C54A-04I/SO (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Timers, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
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Request AlternativesPIC16C54A-04I/SO Maximum Ratings & Electrical Characteristics
| Family | PIC® 16C |
| Core | 8-bit RISC PIC16C5X |
| Program Memory Type | OTP (One-Time-Programmable EPROM) |
| Program Memory Size | 768 B (512 x 12 words) |
| Data RAM | 25 B |
| Maximum CPU Frequency | 4 MHz |
| Instruction Word Width | 12 bits |
| Data Path Width | 8 bits |
| Operating Supply Voltage | 4.5 V to 5.5 V |
| I/O Pins | 12 |
| Timers | 1 x 8-bit (TMR0) |
| Hardware Stack Depth | 2 levels |
| Addressing Modes | Direct, Indirect, Relative |
| Package | 18-SOIC (0.295 inch / 7.50 mm body width) |
| Operating Temperature Range | -40 °C to +85 °C (Industrial / 'I' grade) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (unlimited floor life) |
PIC16C54A-04I/SO Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (bidirectional digital I/O) |
| Pin 2 | RA3 — Port A bit 3 (bidirectional digital I/O) |
| Pin 3 | RTCC — TMR0 real-time clock/counter external input |
| Pin 4 | MCLR — Master Clear reset input (active low, internal pull-up) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Port B bit 0 (bidirectional digital I/O) |
| Pin 7 | RB1 — Port B bit 1 (bidirectional digital I/O) |
| Pin 8 | RB2 — Port B bit 2 (bidirectional digital I/O) |
| Pin 9 | RB3 — Port B bit 3 (bidirectional digital I/O) |
| Pin 10 | RB4 — Port B bit 4 (bidirectional digital I/O) |
| Pin 11 | RB5 — Port B bit 5 (bidirectional digital I/O) |
| Pin 12 | RB6 — Port B bit 6 (bidirectional digital I/O) |
| Pin 13 | RB7 — Port B bit 7 (bidirectional digital I/O) |
| Pin 14 | VDD — Positive supply voltage (4.5 V to 5.5 V) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock output |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 17 | RA0 — Port A bit 0 (bidirectional digital I/O) |
| Pin 18 | RA1 — Port A bit 1 (bidirectional digital I/O) |
Typical Applications
PIC16C54A-04I/SO is suitable for 7 applications: Low-Cost LED Lighting Controller, Small Appliance Control Board, Educational / Hobbyist MCU Trainer, Discrete Logic / Timer Sequencer Replacement, Battery Charger and Simple Power Controller, Industrial Sensor and Indicator Modules, Toy and Consumer Electronics Embedded Controller.
Low-Cost LED Lighting Controller
The PIC16C54A-04I/SO fits simple LED driver and lighting controller designs where one fixed OTP firmware drives up to 12 I/O pins and timing is handled by TMR0 at 4 MHz. Its 512-word OTP program memory is sufficient for chase patterns, dimming ramps, and on/off scheduling stored as lookup tables, while the industrial -40 to +85 C grade allows deployment in outdoor or automotive interior lighting fixtures. Place a 100 nF decoupling cap on VDD and use the MCLR pin with a 10 kohm pull-up for clean resets. Unlike microchip flash MCUs, the OTP die keeps per-unit cost low for high-volume runs of 10k+ units.
Recommended
Small Appliance Control Board
The PIC16C54A-04I/SO is well suited to control boards in toasters, coffee makers, blenders, and small kitchen appliances that need a simple state machine, button debouncing, and relay/triac driving on 12 I/O pins. Its 4 MHz CPU clock and 12-bit instruction word deliver compact code for timers and PWM emulated via TMR0 interrupts, while the 4.5-5.5 V supply matches standard rectified mains-derived rails. OTP storage locks firmware at production time, preventing field tampering and reducing per-unit cost in 100k+ production runs. A 10 uF bulk plus 100 nF ceramic decoupling network at VDD mitigates motor/relay noise back into the MCU.
Recommended
Educational / Hobbyist MCU Trainer
The PIC16C54A-04I/SO is a popular teaching MCU in university embedded systems and electronics hobbyist courses because it exposes the full PIC16C5X instruction set, register architecture, and 12-bit opcode encoding in a clear, easy-to-document way. With 512 words of OTP, 25 bytes of RAM, and only 7 special function registers, students can master the entire memory model in a single semester. Industrial temperature grade allows lab work in unheated spaces. Use the PIC16F54-I/SO for in-circuit reprogramming during coursework, since it shares the same instruction set but adds flash.
Recommended
Discrete Logic / Timer Sequencer Replacement
When designers consolidate a 555-timer, 74HC counter, and discrete flip-flop sequencer into a single chip, the PIC16C54A-04I/SO is a frequent choice. Its 12 I/O pins can replace 3-4 standard logic packages, while the OTP program memory stores the entire timing sequence in 512 words or less, often 2:1 denser than equivalent 8-bit CISC code. Industrial temperature grade handles outdoor or factory-floor enclosures. Estimated BOM savings in volume typically exceed 30 percent versus discrete logic, and OTP eliminates any risk of firmware bit-rot during product lifetime.
Recommended
Battery Charger and Simple Power Controller
The PIC16C54A-04I/SO can run simple lead-acid or NiMH charge profiles using TMR0 for elapsed-time counting and 4-8 I/O pins to drive MOSFET gates and read voltage dividers. Its 4.5-5.5 V supply range matches 6 V battery packs and 5 V regulated rails, and OTP firmware locks the charge algorithm at production. Industrial -40 to +85 C operation supports under-hood or outdoor battery management. Provide at least 100 nF ceramic plus 10 uF electrolytic decoupling on VDD to suppress switching transients from the power stage.
Recommended
Industrial Sensor and Indicator Modules
The PIC16C54A-04I/SO fits simple sensor-interface modules that read a digital input, apply a threshold or pulse-count routine, and drive status LEDs or relays. Its 12 I/O pins support up to four digital sensors plus four indicator outputs, and the OTP program space handles state tables for alarm priorities. Industrial temperature grade ensures reliable operation in factory cabinets and outdoor enclosures. With a footprint of 7.5 mm wide, the SOIC-18 package fits into space-constrained DIN-rail modules. A 100 nF decoupling capacitor within 5 mm of VDD is mandatory per Microchip layout guidelines.
Recommended
Toy and Consumer Electronics Embedded Controller
The PIC16C54A-04I/SO powers low-end toys, talking gadgets, and consumer novelties where the firmware is locked at production and unit cost must stay below one dollar. Its 512-word OTP memory easily stores sound playback tables, motor sequences, and button-debounce state machines for these applications. Industrial temperature grade ensures reliable operation across climate zones, and the SOIC-18 package supports automated pick-and-place assembly on high-volume lines. Once the design is validated, Microchip offers last-time-buy support to lock supply for the product lifetime, but new designs should target the PIC16F54-I/SO flash MCU.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54A-04I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54A-04I/P | PIC16C54A-04/SO | PIC16C54C-04/SO | PIC16C54A-04/SS | PIC16C54A-04E/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SOIC-18 (0.295 inch) | PDIP-18 - through-hole equivalent | SOIC-18 - same | SOIC-18 - same | SSOP-20 with 2 NC pins | SSOP-20 with 2 NC pins |
| Program Memory | 768 B (512 x 12 OTP) | 768 B (512 x 12 OTP) - same | 768 B (512 x 12 OTP) - same | 768 B (512 x 12 OTP) - same | 768 B (512 x 12 OTP) - same | 768 B (512 x 12 OTP) - same |
| Maximum Clock Frequency | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same | 4 MHz - same | 4 MHz - same |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C - same | 0 C to +70 C (Commercial) | 0 C to +70 C (Commercial) | 0 C to +70 C (Commercial) | -40 C to +125 C (Extended) |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V - same | 4.5 V to 5.5 V - same | 4.5 V to 5.5 V - same | 4.5 V to 5.5 V - same | 4.5 V to 5.5 V - same |
| Data RAM | 25 B | 25 B - same | 25 B - same | 25 B - same | 25 B - same | 25 B - same |
| I/O Pins | 12 | 12 - same | 12 - same | 12 - same | 12 + 2 NC - same active count | 12 + 2 NC - same active count |
| Silicon Revision | PIC16C54A (original 'A' die) | PIC16C54A - same | PIC16C54A - same | PIC16C54C (later revision) | PIC16C54A - same | PIC16C54A - same |
Key Differentiators
- Industrial temperature grade in SOIC-18 footprint (vs PIC16C54A-04/SO)
- Later silicon revision available for the same footprint (vs PIC16C54C-04/SO)
- Through-hole drop-in option with identical industrial grade (vs PIC16C54A-04I/P)
Design Notes
Estimated: at VDD = 5.0 V and 4 MHz CPU clock, the PIC16C54A-04I/SO draws approximately 1.8 mA active and 1 uA typical standby (watchdog disabled). Place a 100 nF ceramic decoupling capacitor within 5 mm of pin 14 (VDD) and a 10 uF bulk capacitor on the same supply rail; for noisy relay-driven boards, add a ferrite bead in series with VDD. If using sleep mode, ensure MCLR (pin 4) is not floating - tie it to VDD via a 10 kohm pull-up to avoid spurious wake-ups. Brown-out detection is not present on this die, so external voltage supervision is required for mission-critical applications.
The 18-SOIC (0.295 inch body) footprint requires 1.27 mm pin pitch. Route all digital I/O traces with at least 0.2 mm clearance to analog or oscillator traces, and keep the crystal or resonator within 5 mm of pins 15 and 16 (OSC2/CLKOUT, OSC1/CLKIN). Add a guard ring around the oscillator pins tied to VSS to reduce EMI. For noisy industrial environments, place a 100 ohm series resistor on MCLR (pin 4) to limit reset transients. OTP programming requires a high-voltage VPP on MCLR (~13 V) during programming mode, so design the reset network to tolerate VPP without latching upstream supervisors.
Common pitfalls with the PIC16C54A-04I/SO include: (1) confusing the 'I' (industrial) suffix with the 'E' (extended -40 to +125 C) suffix - some vendors misuse these labels; (2) assuming the PIC16C54C is the same die as PIC16C54A - it is a later revision but register-compatible at 4 MHz, but minor errata differences exist at higher clock rates; (3) using a non-OTP programmer and losing firmware in the field - the OTP cell can only be written once, so prototype with the PIC16F54-I/SO instead; (4) forgetting the 12-bit instruction word width when porting code from 14-bit PIC16F MCUs - the opcode format is different and will not assemble correctly.
Compliance Information
RoHS and REACH status were not explicitly stated in the verified web data; lead-free is assumed for the SOIC package per Microchip's standard assembly materials. The PIC16C5X family is industrial/commercial grade and is NOT AEC-Q100 qualified for automotive use; AEC-Q100 status is therefore not applicable. For conflict minerals, Microchip publishes a compliant CMRT declaration on its corporate responsibility page.
