PIC16C54A-04/SO - 8-Bit 4MHz OTP MCU, 18-SOIC | Microchip
MPN: PIC16C54A-04/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.1 | $2.10 |
| 10 | $1.95 | $19.50 |
| 100 | $1.75 | $175.00 |
| 500 | $1.55 | $775.00 |
| 1,000 | $1.4 | $1,400.00 |
PIC16C54A-04/SO Overview
An OTP microcontroller is a member of the broader microcontroller family, which itself belongs to the embedded processing class of semiconductors. Within the PIC16C5x hierarchy, the PIC16C54A sits at the low-pin-count, low-memory tier (768B code, 25B RAM, 12 I/O pins) and is positioned below the PIC16C55/56/57/58 variants. The part is designed for cost-sensitive, high-volume embedded control where ROM/EPROM/Flash flexibility is unnecessary and one-time factory or in-circuit programming at production time is acceptable.
Key features include a 12-bit instruction word with 33 single-word instructions, a two-level deep stack for subroutine nesting, seven or eight special-function hardware registers, an 8-bit real-time counter/timer (TMR0) with 8-bit prescaler, direct/indirect/relative addressing modes, and 12 bidirectional digital I/O pins grouped into two ports (PORTB, PORTA-style). Power-saving SLEEP mode and a Watchdog Timer (WDT) are provided for unattended and brown-out-tolerant applications, though the commercial-temperature PIC16C54A does not include the Low-Voltage Programming (LVP) feature found on later F-series parts.
The PIC16C5x architecture uses a 12-bit-wide instruction set with an 8-bit-wide data path, yielding approximately 2:1 code compression versus other 8-bit microcontrollers in its class and giving the PIC16C54A a meaningful performance/cost advantage in timing-sensitive control loops. Two addressing modes for data plus a two-level hardware stack make assembly code portable across the 16C5x/16F5x family, simplifying migration to PIC16F54 when flash-based reprogramming is desired.
Typical applications include simple appliance controllers, remote-control transmitters, LED driving and lighting controllers, battery chargers, sensor signal conditioning, smart toys and consumer gadgets, automotive body and interior modules, and any cost-driven 5V embedded node. The 18-pin SOIC footprint keeps the BOM small and the PCB layout straightforward for hand-solderable prototypes as well as high-volume reflow assembly.
When designing with the PIC16C54A-04/SO, choose a 4 MHz crystal or external clock with two 22 pF loading capacitors and ensure the MCLR reset network (typically 10 kohm pull-up plus 100 nF cap) is present. Because the memory is OTP, firmware bugs cannot be field-updated, so a verified production flow (or migration to PIC16F54 for development convenience) is recommended. This page synthesizes distributor pricing, drop-in alternatives and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC16C54A-04/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-04/SO (same form factor and footprint) — differing in Program Memory Type, Program Memory Size, Package, Timers, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C54C-04/SO
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →PIC16C54A-04I/SO
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC16C54CT-04/SO
✅ Drop-In✓ In Stock
$1.41 / Unit
View Datasheet →PIC16F54-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C54A-04/SO Maximum Ratings & Electrical Characteristics
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 768 B (512 x 12) |
| RAM Size | 25 B |
| CPU Speed | 4 MHz |
| Instruction Set Width | 12-bit |
| Data Path Width | 8-bit |
| Number of I/O Pins | 12 |
| Supply Voltage (Vdd) | 4.5 V to 5.5 V |
| Operating Temperature Range | 0C to +70C (Commercial) |
| Package | 18-SOIC (SOIC-18, 0.300") |
| Timers | 1 x 8-bit (TMR0) with 8-bit prescaler |
| Stack Depth | 2 levels (hardware) |
| Watchdog Timer | Yes |
| ADC | None (digital-only) |
| Mounting Type | Surface Mount |
PIC16C54A-04/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 (also digital I/O on some revisions) |
| Pin 4 | MCLR — Master clear reset input (active low, external pull-up required) |
| 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 | RB3 — Bidirectional I/O port B, bit 3 |
| Pin 10 | RB4 — Bidirectional I/O port B, bit 4 |
| Pin 11 | RB5 — Bidirectional I/O port B, bit 5 |
| Pin 12 | RB6 — Bidirectional I/O port B, bit 6 |
| Pin 13 | RB7 — Bidirectional I/O port B, bit 7 |
| Pin 14 | Vdd — Positive supply, 4.5 V to 5.5 V |
| Pin 15 | OSC2 — Oscillator output (crystal/ceramic resonator) |
| Pin 16 | OSC1 — Oscillator input (crystal/ceramic resonator or external clock) |
| Pin 17 | RA0 — Bidirectional I/O port A, bit 0 |
| Pin 18 | RA1 — Bidirectional I/O port A, bit 1 |
Typical Applications
PIC16C54A-04/SO is suitable for 7 applications: Appliance Control Boards, Remote Control Transmitters, LED Lighting Controllers, Battery Chargers, Automotive Body & Interior Controllers, Smart Toys & Consumer Gadgets, Sensor Signal Conditioning Nodes.
Appliance Control Boards
The PIC16C54A-04/SO is well-suited to appliance controllers (microwaves, washing machines, coffee makers) where its 12 GPIO pins can drive relays, triacs, keypads and 7-segment LEDs directly. Its 768 B OTP (512 x 12-bit words) is sufficient for typical state-machine firmware with timing routines, and the 4 MHz CPU gives 1 microsecond instruction execution for fast loop response. The 18-SOIC footprint keeps the PCB small for integration inside tight enclosures. Engineers commonly place this MCU between a 5 V LDO and the user interface, using TMR0 for timing the wash cycle or heating element.
Recommended
Remote Control Transmitters
For IR/RF remote-control transmitters, the PIC16C54A-04/SO's minimal pin count and 25 B data RAM are exactly what's required to encode button presses and drive an IR LED or SAW transmitter. Its 4 MHz instruction rate easily generates 38 kHz carrier modulation for IR protocols, and the SLEEP mode with watchdog wake-up minimizes idle current for battery-powered remotes. The 12-bit instruction word keeps the encoding firmware compact (typically under 256 words), fitting within the 768 B OTP budget. A typical circuit places a 4 MHz ceramic resonator on OSC1/OSC2 with two 22 pF caps.
Recommended
LED Lighting Controllers
The PIC16C54A-04/SO is commonly used to drive LED strings, RGB controllers and decorative lighting where precise PWM-like timing is needed across multiple channels. With TMR0 plus software loops, the 4 MHz CPU can multiplex several LED digits or fade RGB channels without external driver ICs. The 12 GPIO pins are sufficient for 7-segment displays plus key inputs or DMX-style signal generation. Power consumption is low (a few mA active), and the OTP memory prevents accidental firmware tampering in commercial lighting products.
Recommended
Battery Chargers
The PIC16C54A-04/SO can serve as the supervisory microcontroller in simple NiCd/NiMH/Li-ion charger designs, using TMR0 to time charge phases and GPIO to drive MOSFET switches and indicator LEDs. Its 4.5-5.5 V supply range pairs naturally with USB or 6 V wall-adapter inputs through an LDO. The 25 B RAM is sufficient for state counters, and the two-level stack handles one nested interrupt context. A typical circuit uses the MCLR pin with a 10 kohm pull-up for clean reset on power-up.
Recommended
Automotive Body & Interior Controllers
For cost-sensitive automotive body controllers (interior lighting, mirror adjust, simple seat controllers), the industrial-temperature PIC16C54A-04I/SO variant (same die, -40C to +85C) is preferred. The 12 GPIO pins drive relays and FET pre-drivers, while TMR0 schedules debounce and PWM-style soft-start routines. The 18-SOIC package withstands typical automotive PCB reflow profiles. AEC-Q100 qualification is not claimed on this part, so it is generally limited to non-safety body modules rather than powertrain or chassis.
Recommended
Smart Toys & Consumer Gadgets
The PIC16C54A-04/SO is widely used in toy electronics, novelties and consumer gadgets where unit cost is the dominant constraint and OTP prevents firmware piracy. Its 768 B program memory fits simple sound-effect sequences, motor control loops and LED animations, and the 25 B RAM is enough for state variables. The 4 MHz clock supports software-generated tone output for piezo buzzers. Typical BOM pairs the MCU with a 4 MHz crystal, two 22 pF caps, a reset network and a 5 V regulator.
Recommended
Sensor Signal Conditioning Nodes
The PIC16C54A-04/SO can be used as a low-cost signal-conditioning MCU that reads digital sensors (Hall-effect switches, PIR outputs, reed switches) and drives indicator LEDs or simple serial bit-banged outputs. Although it has no on-chip ADC, external sigma-delta or comparator-front-end ICs can be polled via GPIO. The 4 MHz CPU gives predictable timing for debounce, hysteresis and serial framing routines, while the OTP memory locks calibration constants at production.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54A-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54C-04/SO | PIC16C54A-04I/SO | PIC16C54CT-04/SO | PIC16F54-I/SO |
|---|---|---|---|---|---|
| Package | 18-SOIC (0.300") | 18-SOIC - same | 18-SOIC - same | 18-SOIC - same | 18-SOIC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| CPU Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz instruction rate (20 MHz max) |
| Program Memory | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP | 768 B Flash |
| RAM | 25 B | 25 B | 25 B | 25 B | 25 B |
| I/O Pins | 12 | 12 | 12 | 12 | 12 |
| 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 (broader) |
| Operating Temperature | 0C to +70C (Commercial) | 0C to +70C | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| Memory Type | OTP | OTP | OTP | OTP | Flash (reprogrammable) |
Key Differentiators
- Lowest unit cost in the PIC16C5x OTP family (vs PIC16F54-I/SO)
- Commercial temperature grade for cost-sensitive consumer products (vs PIC16C54A-04I/SO)
- Established long-term availability through broad distributor stock (vs PIC16C54CT-04/SO)
Design Notes
Power the PIC16C54A-04/SO from a regulated 5 V supply with a 100 nF decoupling capacitor as close as possible to Vdd (pin 14) and a 10 microfarad bulk capacitor on the same rail. Because the part is OTP and fully static, brownouts will not corrupt code but can leave registers in an indeterminate condition; use the MCLR pin with a 10 kohm pull-up and 100 nF cap to guarantee a clean reset on power-up.
Connect a 4 MHz crystal or ceramic resonator between OSC1 (pin 16) and OSC2 (pin 15) with two 22 pF load capacitors to ground. For cost-sensitive designs a 4 MHz external CMOS clock can drive OSC1 directly; in that configuration OSC2 can be left floating. Avoid using slow starting resonators that delay instruction accuracy beyond the application's timing budget.
Use a continuous ground plane under the 18-SOIC footprint and route Vdd as a star from the regulator. Group the high-current GPIO traces (LED rows, relay drivers) away from the oscillator traces to prevent switching noise from corrupting the clock - keep at least 5 mm of separation or use a guard ground trace.
OTP memory cannot be erased: once the part is programmed, firmware bugs are permanent, so always verify code on a flash equivalent (PIC16F54 or PIC16C54C development setup) before programming production parts. The PIC16C54A has no on-chip ADC, no UART and only a two-level hardware stack - complex C-style algorithms will not fit; restrict code to assembly or highly optimized state machines.
Compliance Information
RoHS/REACH/lead-free status not stated in the retrieved web data and must be confirmed against the manufacturer product page before use in regulated products. The PIC16C54A is Not Recommended for New Designs (NRND) per Microchip and is NOT AEC-Q100 qualified.
