PIC16C54CT-20I/SO - 8-Bit 20MHz OTP MCU, 18-SOIC | Microchip
MPN: PIC16C54CT-20I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.95 | $1.95 |
| 10 | $1.72 | $17.20 |
| 100 | $1.45 | $145.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $0.95 | $950.00 |
PIC16C54CT-20I/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and peripheral interfaces (timers, I/O, communications). The PIC16C5X family occupies the lowest tier of Microchip's 8-bit PIC architecture hierarchy (MCU -> microcontroller -> 8-bit MCU -> PIC16 -> PIC16C5X baseline), using a 12-bit-wide instruction set with 33 single-cycle opcodes. This 2:1 code compression versus typical 8-bit CISC architectures of its era made the PIC16C5X popular in high-volume, ROM/EPROM-driven appliance and industrial control designs.
Key features of this variant include 20 MHz maximum clock speed, 12 I/O pins shared with peripheral functions, a hardware watchdog timer for unattended operation, and OTP program memory suited for low-volume production runs where in-field updates are not required. The 'I' suffix denotes an industrial operating range of -40 °C to +85 °C, while 'CT' identifies tape-and-reel packaging and '20' the 20 MHz speed grade. OTP parts replace the older UV-erasable windowed CERDIP PIC16C54, eliminating the quartz erase window for surface-mount assembly.
Architecturally, the PIC16C54C uses a Harvard RISC core with a 2-stage pipeline, two 8-bit file registers, an 8-bit ALU, and a dedicated hardware stack. The OTP program memory is written once via standard Microchip device programmers; field updates require device replacement. The external oscillator mode supports RC, XT, LP, and HS oscillator types with appropriate passive component selection, giving designers flexibility between low-power (LP, ~32 kHz) and high-speed (HS, 20 MHz) operation.
Typical applications include low-cost appliance controllers (washing machines, microwave ovens, HVAC fan controls), simple sensor interfaces, LED driving sequences, and battery-backed alarm or timing subsystems. Industrial-grade parts are also deployed in factory automation auxiliary controls where extended temperature tolerance and long-term Microchip supply commitments are valued over the latest peripheral mix.
When designing with this MCU, reserve RA0-RA3 and RB0-RB7 for general digital I/O and verify the chosen oscillator mode against the supply voltage and frequency expected. Ensure decoupling is placed within 5 mm of VDD/VSS pins, and program the CONFIG word for the correct oscillator and watchdog behavior before the first OTP write, since OTP memory cannot be re-programmed.
Drop-in alternatives for PIC16C54CT-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 PIC16C54CT-20I/SO (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Operating Temperature, MSL Level.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C54C-20I/SO
✅ Drop-In✓ In Stock
$1.15 / Unit
View Datasheet →PIC16C54CT-20/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C54CT-20E/SO
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →PIC16C54AT-20/SO
✅ Drop-In✓ In Stock
$2.15 / Unit
View Datasheet →PIC16C54C-20I/SS
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC16C54A-20I/SO
✅ Drop-In✓ In Stock
$1.15 / Unit
View Datasheet →PIC16C54CT-20I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 768 B (512 x 12) |
| RAM Size | 25 B |
| Maximum Clock Speed | 20 MHz |
| Supply Voltage (VDD) | 4.5 V to 5.5 V |
| I/O Pins | 12 |
| Package | 18-SOIC (7.50 mm width, 0.295") |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 °C to +85 °C (Industrial) |
| Oscillator Type | External (RC, XT, LP, HS) |
| Watchdog Timer | Yes (WDT) |
| Power-On Reset | Yes (POR) |
| Instruction Set Width | 12-bit |
| Number of Instructions | 33 |
| MSL Level | MSL-1 (per JEDEC J-STD-020) |
| RoHS Status | Compliant |
PIC16C54CT-20I/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O pin / bit 2 of port A |
| Pin 2 | RA3 — Bidirectional I/O pin / bit 3 of port A |
| Pin 3 | RTCC — Real-Time Clock/Counter input (TMR0 external clock) |
| Pin 4 | MCLR — Master Clear (reset) input, active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Bidirectional I/O pin / bit 0 of port B |
| Pin 7 | RB1 — Bidirectional I/O pin / bit 1 of port B |
| Pin 8 | RB2 — Bidirectional I/O pin / bit 2 of port B |
| Pin 9 | RB3 — Bidirectional I/O pin / bit 3 of port B |
| Pin 10 | RB4 — Bidirectional I/O pin / bit 4 of port B |
| Pin 11 | RB5 — Bidirectional I/O pin / bit 5 of port B |
| Pin 12 | RB6 — Bidirectional I/O pin / bit 6 of port B |
| Pin 13 | RB7 — Bidirectional I/O pin / bit 7 of port B |
| Pin 14 | VDD — Positive supply voltage (4.5 V to 5.5 V) |
| Pin 15 | OSC2 — Oscillator output / external clock return |
| Pin 16 | OSC1 — Oscillator input / external clock source |
| Pin 17 | RA0 — Bidirectional I/O pin / bit 0 of port A |
| Pin 18 | RA1 — Bidirectional I/O pin / bit 1 of port A |
Typical Applications
PIC16C54CT-20I/SO is suitable for 6 applications: White Goods Appliance Control, HVAC Fan and Damper Control, LED Sequence and Chase Lighting, Simple Sensor Interface Hubs, Battery-Backed Alarm and Timer Subsystems, Industrial Auxiliary Control.
White Goods Appliance Control
The PIC16C54CT-20I/SO's 768 B OTP and 12 GPIO lines at 20 MHz match the typical control loops found in white goods: motor direction sequencing, sensor polling, and LED indicators. The device's -40 to +85 C industrial rating covers under-counter and garage environments. With 25 B of RAM, designers implement simple state machines without an external bus. The OTP memory model suits the high-volume, firmware-stable nature of appliance lines where every cent of BOM cost matters.
Recommended
HVAC Fan and Damper Control
In heating, ventilation, and air-conditioning subsystems, the PIC16C54CT-20I/SO drives triac-controlled fan motors and reads NTC temperature sensors with its 12 GPIO. The 20 MHz instruction rate easily handles 10 ms control loops typical for indoor blower modulation. Industrial-grade operation tolerates attic and basement installations. Power-On Reset and Watchdog Timer ensure unattended, fail-safe recovery from brown-outs and firmware hangs.
Recommended
LED Sequence and Chase Lighting
For decorative chase lighting, marquee displays, and signage animation, the PIC16C54CT-20I/SO drives up to 12 LED channels directly from its GPIO with bit-banged patterns updated at up to 5 MHz instruction throughput. The industrial temperature range enables outdoor installations. The Watchdog Timer recovers the system if a lighting pattern fault locks the CPU. The OTP memory model matches fixed lighting sequences shipped in millions of identical units.
Recommended
Simple Sensor Interface Hubs
As a sensor-interface hub, the PIC16C54CT-20I/SO aggregates digital inputs from limit switches, reed sensors, and rotary encoders, then drives relays or buzzer outputs. The 12 I/O lines accommodate 8 inputs plus 4 outputs in a typical burglar-alarm keypad or door-control panel. Industrial temperature operation tolerates unheated warehouse and outdoor cabinet installations. Brown-out recovery via the integrated Power-On Reset ensures clean startup after power interruptions.
Recommended
Battery-Backed Alarm and Timer Subsystems
In battery-backed alarm panels and timer subsystems, the PIC16C54CT-20I/SO's low-power LP oscillator mode (32 kHz watch crystal) keeps quiescent draw in the microamp range while still running real-time scheduling. The Watchdog Timer recovers the device if a software lockup disables the alarm loop. With 768 B of program memory and 25 B of RAM, the PIC16C54CT-20I/SO fits typical alarm firmware under 400 instructions. Industrial temperature tolerance handles unheated equipment rooms.
Recommended
Industrial Auxiliary Control
Factory automation auxiliary controls (conveyor starters, indicator towers, push-button remotes) use the PIC16C54CT-20I/SO as a dedicated logic coordinator. The 12 GPIO lines scan 8 push-button inputs and drive 4 indicator outputs, while the 20 MHz instruction rate processes debouncing and sequencing without external logic. The industrial temperature range tolerates cabinet environments where temperatures routinely exceed 60 C. The OTP memory model aligns with fixed-function industrial designs where firmware changes are infrequent.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54CT-20I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54C-20I/SO | PIC16C54CT-20/SO | PIC16C54CT-20E/SO | PIC16C54AT-20/SO | PIC16C54C-20I/SS | PIC16C54A-20I/SO |
|---|---|---|---|---|---|---|---|
| Package | 18-SOIC (7.50 mm) | 18-SOIC (7.50 mm) - same | 18-SOIC (7.50 mm) - same | 18-SOIC (7.50 mm) - same | 18-SOIC (7.50 mm) - same | 18-SSOP - smaller footprint, same pinout | 18-SOIC (7.50 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Clock Speed (max) | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Program Memory Size | 768 B (512 x 12) OTP | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP |
| RAM Size | 25 B | 25 B | 25 B | 25 B | 25 B | 25 B | 25 B |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +125 C (Extended) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) |
| Silicon Revision | 'C' revision | 'C' revision | 'C' revision | 'C' revision | 'A' revision | 'C' revision | 'A' revision |
| Packaging Form | Tape & Reel | Tube | Tape & Reel | Tape & Reel | Tape & Reel | Tube | Tube |
Key Differentiators
- Same-die part with tube packaging for through-hole and prototype assembly (vs PIC16C54C-20I/SO)
- Industrial temperature grade covers -40 C to +85 C factory and outdoor deployments (vs PIC16C54CT-20/SO)
- 'C' silicon revision offers improved ESD and tighter oscillator specs (vs PIC16C54AT-20/SO)
Design Notes
Estimated: The PIC16C54CT-20I/SO draws approximately 2.5 mA at 5 V, 20 MHz with all 12 GPIO switching (per PIC16C5X datasheet DC characteristics, ICC = 2.5 mA typical at 20 MHz). Add a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 14) and a bulk 10 µF electrolytic on the same supply rail to suppress switching noise from internal clock edges. Without proper decoupling, brown-out events above VDD = 4.5 V can trigger spurious POR resets.
Select the CONFIG word oscillator mode based on the crystal frequency: RC (low-cost RC network), LP (32-200 kHz low-power), XT (100 kHz-4 MHz), or HS (4-20 MHz). For 20 MHz operation, HS mode is mandatory. Use a fundamental-mode crystal with 20-33 pF load capacitors on OSC1/OSC2. Mismatched capacitance or using XT mode at 20 MHz results in erratic startup or oscillator failure.
Keep the OSC1/OSC2 traces short and surrounded by a ground pour to minimize radiated EMI and stray capacitance. Place the MCLR pull-up resistor (typically 10 kΩ) close to pin 4 and add a 100 nF capacitor to VSS if the reset line is long or routed near noisy signals. Route the VDD and VSS traces as wide as the SOIC pads allow to maintain a low-impedance return path for transient currents.
The PIC16C54CT-20I/SO uses One-Time Programmable memory that CANNOT be re-written. Verify the CONFIG word, oscillator mode, watchdog enable, and code protection bits in simulation before programming. For prototype development, use a windowed CERDIP PIC16C54 (PIC16C54/JW) or migrate to the flash-based PIC16F54. A mis-configured OTP part is a bricked part.
Compliance Information
RoHS compliant per Microchip product declaration. REACH SVHC declaration not explicitly listed in distributor pages reviewed; consult Microchip's product environmental compliance documentation. Not AEC-Q100 qualified - the 'I' suffix is industrial, not automotive grade.
