PIC16C54A-20I/SO - 8-Bit 20MHz OTP MCU 768B | Microchip
MPN: PIC16C54A-20I/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.76 | $1.76 |
| 10 | $1.58 | $15.80 |
| 100 | $1.42 | $142.00 |
| 500 | $1.28 | $640.00 |
| 1,000 | $1.15 | $1,150.00 |
PIC16C54A-20I/SO Overview
An 8-bit microcontroller is a small computing system-on-chip integrating an 8-bit CPU core, program memory, data RAM, and peripheral interfaces. The PIC16C5X family uses a RISC architecture with 33 single-word/single-cycle instructions, achieving 2:1 code compression versus competing 8-bit MCUs in its class. It executes most instructions in 200 ns at 20 MHz, providing deterministic timing suitable for cost-sensitive embedded control. The PIC16C54A specifically targets applications requiring absolute minimalism — no interrupts, two-level hardware stack, and seven/eight SFRs — making it a baseline controller for hard real-time logic.
Key features include a 12-bit wide instruction word with 8-bit data path, an 8-bit real-time clock/counter (TMR0), direct/indirect/relative addressing modes, 12 I/O pins, and an integrated power-on reset / brown-out detector on later revisions. The wide operating voltage (4.0V–6.0V) and industrial temperature range (-40°C to +85°C, denoted by the 'I' suffix) suit industrial, automotive aftermarket, and consumer appliances.
Typical applications include timer replacements, smart-card readers, simple motor drives, security keypads, and battery chargers. The EPROM-based OTP memory makes it ideal for low-volume production where Flash reprogrammability is unnecessary but fast time-to-market matters.
When designing with this part, note that the PIC16C54A is now flagged as Not Recommended for New Designs by Microchip — consider the Flash-based PIC16F54 as a modern drop-in equivalent for new projects, while continuing to source the OTP version for legacy repairs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes that go beyond what the manufacturer datasheet alone provides, including lifecycle guidance for NRND parts.
Drop-in alternatives for PIC16C54A-20I/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-20I/SO (same form factor and footprint) — differing in Package, Operating Temperature, Program Memory Size, Program Memory Type, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C54A-20/SO
✅ Drop-In✓ In Stock
$1.4 / Unit
View Datasheet →PIC16C54A-04I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C54A-10I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F54-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C54C-20I/SO
✅ Drop-In✓ In Stock
$1.15 / Unit
View Datasheet →PIC16C54A-20I/SO Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC® 16C |
| Core Processor | PIC |
| Core Size | 8-Bit |
| Maximum Clock Frequency | 20 MHz |
| Program Memory Size | 768 B (512 × 12) OTP |
| RAM Size | 25 B |
| Number of I/O Pins | 12 |
| Data Converters | None |
| Oscillator Type | External |
| Operating Voltage Range | 4.0 V to 6.0 V |
| Operating Temperature Range | -40 °C to +85 °C (Industrial, 'I' suffix) |
| Package / Case | 18-SOIC (SO, 0.295 inch, 7.50 mm width) |
| Mounting Type | Surface Mount |
| Program Memory Type | OTP (One-Time Programmable, EPROM) |
| Instruction Set Width | 12-bit |
| Stack Depth | 2 hardware levels |
| Number of Instructions | 33 single-word/single-cycle |
| Instruction Cycle Time | 200 ns @ 20 MHz |
| Peripherals | TMR0 8-bit timer/counter, POR (power-on reset) |
| RoHS Status | Compliant (lead-free SO package) |
| Lifecycle Status | Not Recommended for New Designs (NRND) |
| Recommended Replacement | PIC16F54-I/SO (Flash-based, drop-in) |
PIC16C54A-20I/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O pin; bit 2 of PORTA |
| Pin 2 | RA3 — Bidirectional I/O pin; bit 3 of PORTA |
| Pin 3 | T0CKI — Timer0 clock input (shared with RA4) |
| Pin 4 | MCLR — Master Clear (Reset) input, active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Bidirectional I/O pin; bit 0 of PORTB |
| Pin 7 | RB1 — Bidirectional I/O pin; bit 1 of PORTB |
| Pin 8 | RB2 — Bidirectional I/O pin; bit 2 of PORTB |
| Pin 9 | RB3 — Bidirectional I/O pin; bit 3 of PORTB |
| Pin 10 | RB4 — Bidirectional I/O pin; bit 4 of PORTB |
| Pin 11 | RB5 — Bidirectional I/O pin; bit 5 of PORTB |
| Pin 12 | RB6 — Bidirectional I/O pin; bit 6 of PORTB |
| Pin 13 | RB7 — Bidirectional I/O pin; bit 7 of PORTB |
| Pin 14 | VDD — Positive supply voltage (4.0 V to 6.0 V) |
| Pin 15 | OSC2 — Oscillator output (crystal/RC clock driver) |
| Pin 16 | OSC1 — Oscillator input (crystal/RC/external clock) |
| Pin 17 | RA0 — Bidirectional I/O pin; bit 0 of PORTA |
| Pin 18 | RA1 — Bidirectional I/O pin; bit 1 of PORTA |
Typical Applications
PIC16C54A-20I/SO is suitable for 6 applications: Timer and Sequencer Replacements, Smart Card and RFID Reader Controllers, Security Keypads and Access Control Panels, Battery Chargers and Power Management Controllers, Small Appliance and White-Goods Control, Automotive Aftermarket Accessories.
Timer and Sequencer Replacements
The PIC16C54A-20I/SO replaces legacy 555/4020-based timer circuits with a programmable solution delivering 20 MHz timing precision (200 ns instruction cycle) and 768 bytes of OTP code storage. Its 8-bit TMR0 counter combined with software loops enables accurate delays from microseconds to hours without external components. The 18-SOIC industrial-grade package (-40 °C to +85 °C) is ideal for replacing electromechanical timers in industrial control panels where determinism and PCB integration matter more than processing headroom.
Recommended
Smart Card and RFID Reader Controllers
The PIC16C54A-20I/SO serves as the protocol controller in low-cost smart-card and 125 kHz RFID readers, where its 12-bit instruction word and 33-instruction RISC core provide deterministic bit-banging of ISO 7816 or EM4100 protocols. The 768-byte OTP program memory stores the card-handshake routines and security algorithms, while the 25-byte RAM holds transient buffers. With 20 MHz throughput, the MCU meets the 9600–115200 baud smart-card timing requirements at industrial temperature grade, and its compact 18-SOIC footprint suits miniaturized reader PCBs.
Recommended
Security Keypads and Access Control Panels
Security keypads and access-control panels benefit from the PIC16C54A-20I/SO's deterministic response time (200 ns instruction cycle, 2-level hardware stack enabling rapid pin-code validation). Its 12 I/O pins drive 4×4 key-scan matrices directly while leaving pins for relay outputs and buzzer control. The OTP memory locks firmware against reverse-engineering, which is critical for anti-tamper security products. The 18-SOIC industrial-grade (-40 °C to +85 °C) rating ensures reliable operation in outdoor enclosures across climates from winter cold to desert heat.
Recommended
Battery Chargers and Power Management Controllers
Linear and switch-mode battery chargers use the PIC16C54A-20I/SO as the supervisory controller, where its 12-bit instruction word encodes CC/CV charge profiles and safety timers in 768 bytes of OTP. The 8-bit TMR0 generates PWM control signals at 20 MHz with sub-microsecond resolution, while the 12 I/O pins drive MOSFET gates, monitor voltage dividers, and control status LEDs. The 4.0 V–6.0 V supply range matches single-cell Li-ion and 6 V lead-acid systems, and the industrial temperature grade supports outdoor charger enclosures.
Recommended
Small Appliance and White-Goods Control
Small appliances like rice cookers, coffee makers, and bread machines deploy the PIC16C54A-20I/SO as the user-interface controller, reading button inputs, driving 7-segment or LCD displays, and switching relay outputs. Its 20 MHz throughput easily handles 100 Hz display refresh rates and concurrent thermostat sampling. The 12 I/O pins comfortably drive 4-digit 7-segment panels and triac gates, while the 768-byte OTP holds preset recipes. Industrial temperature grade (-40 °C to +85 °C) and 18-SOIC PCB footprint suit both countertop and built-in appliance designs.
Recommended
Automotive Aftermarket Accessories
Automotive aftermarket accessories such as alarm modules, remote-starters, and lighting controllers use the PIC16C54A-20I/SO as a low-cost deterministic controller with industrial temperature range (-40 °C to +85 °C) suitable for cabin installations. Its 12-bit instruction word executes security-code matching and PWM lighting fades in 768 bytes of OTP, with the 25-byte RAM holding transient key-fob buffers. The 18-SOIC surface-mount package suits compact alarm-control PCBs, and the wide 4.0 V–6.0 V supply tolerance handles 12 V vehicle rails after regulator stepping.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54A-20I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54A-20/SO | PIC16C54A-04I/SO | PIC16C54A-10I/SO | PIC16F54-I/SO | PIC16C54C-20I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC (SO) | 18-SOIC (SO) - same | 18-SOIC (SO) - same | 18-SOIC (SO) - same | 18-SOIC (SO) - same | 18-SOIC (SO) - same |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 4 MHz | 10 MHz | 20 MHz | 20 MHz |
| Program Memory | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP | 768 B Flash | 768 B OTP |
| RAM Size | 25 B | 25 B | 25 B | 25 B | 25 B | 25 B |
| Operating Temperature | -40 °C to +85 °C (Industrial) | 0 °C to +70 °C (Commercial) | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| Memory Type | OTP (EPROM) | OTP | OTP | OTP | Flash | OTP |
| Lifecycle Status | NRND | NRND | NRND | NRND | Active | NRND |
Key Differentiators
- Higher 20 MHz clock speed vs 4 MHz grade (vs PIC16C54A-04I/SO)
- Industrial temperature grade (-40 °C to +85 °C) (vs PIC16C54A-20/SO)
- OTP memory locks firmware against extraction (vs PIC16F54-I/SO)
Design Notes
PIC16C54A-20I/SO has only a 2-level hardware stack — subroutines can be nested at most 2 deep. Code that relies on deeper call chains must be flattened into inlined logic, or migrated to PIC16F54 which retains the same architecture. Interrupts are not supported on this baseline part, so all timing must be polled from TMR0 or external interrupts emulated via polling.
Place the decoupling capacitor (100 nF ceramic) within 5 mm of the VDD pin (pin 14), with a direct ground return to VSS (pin 5). For crystal oscillator operation, keep the crystal and load capacitors within 10 mm of OSC1/OSC2 (pins 16/15). Avoid routing digital signal traces under the oscillator traces or near the MCLR pin (pin 4) reset circuit.
The PIC16C54A-20I/SO operates from 4.0 V to 6.0 V with a typical operating current of <2 mA at 5 V/4 MHz and <10 mA at 20 MHz. For battery-powered designs, the PIC16LV54A variant supports 2.0 V–3.8 V operation and consumes under 1 mA at 32 kHz, dramatically extending battery life. Add a 10 µF bulk capacitor at the regulator output to suppress motor-load transients.
Compliance Information
Per Microchip's PIC16C54A product page, the SO package is RoHS-compliant and lead-free. AEC-Q100 not applicable (this is an industrial-grade part, not automotive-qualified). For automotive designs, choose AEC-Q100-qualified PIC16F54 variants.
