PIC16LC54CT-04I/SO - 8-Bit 4MHz OTP MCU, 768B | Microchip
MPN: PIC16LC54CT-04I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.12 | $3.12 |
| 10 | $2.78 | $27.80 |
| 100 | $2.31 | $231.00 |
| 500 | $1.95 | $975.00 |
| 1,000 | $1.62 | $1,620.00 |
PIC16LC54CT-04I/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates an 8-bit CPU core, program memory, data RAM, and peripherals such as timers and I/O ports. The PIC16C5X series, introduced by Microchip in the early 1990s, established the PIC (Peripheral Interface Controller) RISC architecture that became foundational for embedded control. It belongs to the broader hierarchy: 8-bit microcontroller -> microcontroller -> embedded processor -> semiconductor IC, and uses a Harvard architecture with separate program and data buses, allowing simultaneous instruction fetch and operand access. This base MCU class underpins millions of low-cost industrial, automotive, and consumer devices where deterministic timing and code simplicity outweigh raw compute throughput.
Key features of the PIC16LC54CT-04I/SO include 12 I/O pins (GPIO), Power-On Reset (POR), Watchdog Timer (WDT), and OTPROM program memory that is programmed once and cannot be erased, making the device cost-optimized for high-volume, fixed-function applications. The 'LC' suffix denotes the low-voltage CMOS process variant supporting 3.0 V to 6.25 V operation, and the 'T' indicates tape-and-reel packaging. The 33 single-word instruction set provides deterministic execution, ideal for state machines and timing-critical control loops.
Architecturally, the PIC16LC54C uses a 12-bit instruction word, allowing most instructions to execute in a single instruction cycle (4 oscillator clocks), yielding 1 MIPS at 4 MHz. Compared with the original PIC16C54 (which lacked the brown-out reset and configuration bits), the 'C' revision adds oscillator calibration and improved POR behavior. The absence of on-chip debug and Flash means the part is intended for production-only flows where code is finalized before OTP programming.
Typical applications include appliance control (washing machines, microwave ovens, coffee makers), HVAC thermostats, security keypads, simple sensor interfaces, and legacy industrial equipment replacements. The wide 3.0 V to 6.25 V supply range suits both 3.3 V logic and 5 V systems directly.
When designing with this part, note that OTP memory cannot be re-programmed - firmware must be fully validated on a windowed (JW) or emulator part before OTP programming for production. Provide adequate decoupling (0.1 uF ceramic plus bulk) on VDD and ensure MCLR pin handling matches the chosen reset topology (internal or external).
This page synthesizes distributor pricing, verified drop-in alternatives, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC16LC54CT-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 PIC16LC54CT-04I/SO (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Core, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC54C-04I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC54AT-04I/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC16C54CT-04I/SO
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC16LC55A-04I/SO
✅ Drop-In✓ In Stock
$1.4 / Unit
View Datasheet →PIC16LC54CT-04I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Family | PIC16C5X |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 768 bytes (512 x 12 bits) |
| Data RAM | 25 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Set | 33 single-word instructions |
| Instruction Word Length | 12 bits |
| I/O Pins (GPIO) | 12 |
| Supply Voltage Range | 3.0 V to 6.25 V |
| Peripherals | POR (Power-On Reset), WDT (Watchdog Timer) |
| Operating Temperature Range | -40C to +85C (Industrial) |
| Package Type | 18-pin SOIC (7.50 mm body width) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC16LC54CT-04I/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O pin / register select for external memory |
| Pin 2 | RA3 — Bidirectional I/O pin |
| Pin 3 | RA4/T0CKI — Bidirectional I/O pin / Timer0 clock input |
| Pin 4 | MCLR — Master clear reset input (active low) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Bidirectional I/O pin / external interrupt input |
| Pin 7 | RB1 — Bidirectional I/O pin |
| Pin 8 | RB2 — Bidirectional I/O pin |
| Pin 9 | RB3 — Bidirectional I/O pin |
| Pin 10 | RB4 — Bidirectional I/O pin |
| Pin 11 | RB5 — Bidirectional I/O pin |
| Pin 12 | RB6 — Bidirectional I/O pin |
| Pin 13 | RB7 — Bidirectional I/O pin |
| Pin 14 | VDD — Positive supply voltage (3.0 V to 6.25 V) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock output |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 17 | RA0 — Bidirectional I/O pin |
| Pin 18 | RA1 — Bidirectional I/O pin |
Typical Applications
PIC16LC54CT-04I/SO is suitable for 7 applications: White Goods Appliance Control, HVAC Thermostat and Climate Control, Security Keypad and Access Control, Industrial Sensor Interface Module, Battery-Operated Remote Control, Simple LED Lighting Controller, Automotive Interior Accessory Module.
White Goods Appliance Control
The PIC16LC54CT-04I/SO is widely used as the main controller in white goods such as washing machines, dishwashers, and microwave ovens. Its 768-byte OTP memory is sufficient for appliance state machines, button-debounce routines, and simple user-interface code. The 12 GPIO pins directly drive relay drivers, LED indicators, buzzer PWM, and a 7-segment or matrix display without external I/O expanders. The wide 3.0 V to 6.25 V supply range accepts either a regulated 5 V rail or a rectified 12 V down-regulated supply. Compared to a 32-bit MCU solution, this part saves USD 1-2 per unit at production volumes, a critical BOM advantage in cost-sensitive consumer appliances. Use it with companion relay drivers (e.g., ULN2003A) and triac optocouplers for AC load switching.
Recommended
HVAC Thermostat and Climate Control
The PIC16LC54CT-04I/SO's industrial -40C to +85C temperature range and deterministic interrupt handling make it ideal for HVAC thermostat and climate control modules. The 4 MHz clock and 12-bit instruction set provide 1 MIPS throughput, enough to scan temperature sensor inputs (NTC thermistor via ADC), update an LCD driver via GPIO bit-banging, and run a PID control loop on the compressor relay. The 25-byte RAM is sufficient for one or two control variables and a small scheduling array. The 12 GPIO pins multiplex temperature sense, fan relay control, mode-select buttons, and LCD data lines. The 3.0 V minimum supply allows 2-AA battery backup for time-of-day retention across power cycles, an important feature for programmable thermostats. The OTP memory ensures firmware cannot be accidentally overwritten by supply glitches.
Recommended
Security Keypad and Access Control
In security keypads and simple access control panels, the PIC16LC54CT-04I/SO provides a low-cost, secure OTP-based controller for PIN-code verification and door strike activation. The 768-byte OTP memory stores a fixed PIN validation routine, preventing firmware reverse engineering - a security advantage over Flash parts where the binary can be extracted. The 12 GPIO pins drive a 4x3 matrix keypad scan, status LEDs, buzzer, and a relay output for the electric door strike. The 33 single-word instruction set simplifies code review and certification for security-sensitive deployments. The industrial -40C to +85C temperature range supports outdoor keypads in unheated enclosures. The 3.0 V to 6.25 V supply range accepts both 5 V regulated and 12 V down-regulated power typical of access control installations.
Recommended
Industrial Sensor Interface Module
The PIC16LC54CT-04I/SO is well-suited for industrial sensor interface modules that aggregate simple switch or analog inputs and report status over a UART or GPIO bit-bang interface. The 4 MHz clock and 1 MIPS throughput handle polling loops for 4-8 sensor channels with debounce and basic averaging. The 12 GPIO pins are split between sensor inputs, status LEDs, and a half-duplex UART using one TX and one RX pin. The wide 3.0 V to 6.25 V supply supports 24 V industrial bus systems via a simple zener-regulated dropper. The -40C to +85C industrial temperature range meets typical factory-floor environments. The OTP memory locks down calibration coefficients, preventing field tampering. This is a typical PLC remote-I/O digital slice architecture where the PIC16LC54C sits at the bottom of the I/O hierarchy.
Recommended
Battery-Operated Remote Control
For battery-operated remote controls and IR/RF transmitters, the PIC16LC54CT-04I/SO's 3.0 V minimum supply and CMOS process provide modest battery life at low duty cycles. The 768-byte OTP stores fixed command codes for TV, set-top box, or industrial crane remote control. The 12 GPIO pins drive IR LEDs, status confirmation buzzers, and scan a 4x4 keypad matrix. The 33 single-word instruction set keeps firmware simple and verification fast. The 4 MHz clock with most instructions in 1 cycle keeps active-mode current low. The OTP memory prevents end-user firmware tampering or accidental erasure. Compared to a Flash MCU, the OTP variant saves cost at the expense of field upgradeability - acceptable for low-cost disposable-style remotes. Typical battery life extends 1-2 years on 2x AAA cells at modest usage rates.
Recommended
Simple LED Lighting Controller
The PIC16LC54CT-04I/SO serves as a compact controller in simple LED lighting fixtures and decorative lighting products. Its 12 GPIO pins can directly drive multiple MOSFET gates (via gate drivers) for RGBW channels or addressable LED strip data lines. The 768-byte OTP memory stores fixed chase-pattern, dimming curve, or color-cycle routines. The 3.0 V to 6.25 V supply range accepts 5 V USB power or 12 V LED-driver outputs directly. The 4 MHz clock and 1 MIPS throughput handle 8-bit PWM generation via timer interrupts for smooth dimming. The -40C to +85C temperature range supports outdoor-rated luminaires. The OTP memory locks the lighting behavior at production, preventing end-user modification - useful for brand-protection in commercial lighting. This is a typical use case where cost dominates over flexibility.
Recommended
Automotive Interior Accessory Module
While the PIC16LC54CT-04I/SO is not AEC-Q100 qualified, it is used in non-safety automotive interior accessories such as ambient lighting controllers, seat-heater switches, and accessory timers. The -40C to +85C industrial temperature range handles cabin environments. The 768-byte OTP memory stores fixed timing routines for delayed-off accessories. The 12 GPIO pins drive LED indicators, switch inputs, and relay/MOSFET outputs. The 3.0 V to 6.25 V supply range accepts 12 V automotive battery systems via a simple regulator. The OTP memory ensures firmware stability against automotive electrical transients that could potentially corrupt Flash parts. For safety-critical automotive designs, the AEC-Q100-qualified PIC16F variant is required; this part is appropriate only for non-safety accessory modules where cost is the dominant constraint.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC54CT-04I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC54C-04I/SO | PIC16LC54AT-04I/SO | PIC16C54CT-04I/SO | PIC16LC55A-04I/SO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| 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 |
| Program Memory | 768 bytes (512 x 12) OTP | 768 bytes OTP - same | 768 bytes OTP - same | 768 bytes OTP - same | 768 bytes OTP - same |
| Data RAM | 25 bytes | 25 bytes - same | 25 bytes - same | 25 bytes - same | 25 bytes - same |
| Maximum Clock | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same | 4 MHz - same |
| Supply Voltage | 3.0 V to 6.25 V | 3.0 V to 6.25 V - same | 3.0 V to 6.25 V - same | 4.5 V to 5.5 V - narrower (-20%) | 3.0 V to 6.25 V - same |
| I/O Pins | 12 | 12 - same | 12 - same | 12 - same | 12 - same |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C - same | -40C to +85C - same | -40C to +85C - same | -40C to +85C - same |
| Silicon Revision | 'C' revision | 'C' revision - same | 'A' revision - earlier die | 'C' revision (no LC) - same die, std Vdd | 'A' revision (16C55 family) - similar core, different I/O mapping |
Key Differentiators
- Low-voltage 3.0 V to 6.25 V supply range versus standard 4.5 V to 5.5 V PIC16C54 (vs PIC16C54CT-04I/SO)
- Includes 'C' silicon revision with improved POR behavior (vs PIC16LC54AT-04I/SO)
- Tape-and-reel packaging format for SMT production (vs PIC16LC54C-04I/SO)
Design Notes
Estimated: VDD decoupling requires a 0.1 uF ceramic capacitor placed within 5 mm of the VDD pin (14) and a 1 uF to 10 uF bulk capacitor on the same rail. The PIC16LC54CT-04I/SO has modest active current draw (typically 1-2 mA at 4 MHz per the Microchip datasheet) but the supply rail must remain within 3.0 V to 6.25 V under all transient conditions. For battery applications, add a 100 nF plus 10 uF bulk decoupling pair. A series ferrite bead or inductor (10 uH) on VDD can reduce noise coupling from relay or triac loads sharing the same supply.
Estimated: The 18-SOIC package has a 1.27 mm pin pitch and 7.50 mm body width. Provide minimum 0.2 mm clearance between SOIC pins and adjacent traces. Route the MCLR pin trace (pin 4) away from switching load traces to avoid spurious resets. Place the oscillator crystal or resonator within 5 mm of pins 15-16 (OSC2/CLKOUT and OSC1/CLKIN) and guard the oscillator traces with a ground ring to reduce EMI susceptibility. Maintain a continuous ground plane under the MCU for thermal dissipation and EMI reduction. The 18-SOIC has approximately 31 C/W theta_JA per the Microchip package thermal data - acceptable for the modest 1-2 mA active current of this part.
Do not exceed 6.25 V on VDD - the absolute maximum per the datasheet is 7 V, but sustained operation above 6.25 V violates the specification. The MCLR pin (pin 4) requires proper handling: if not used as a reset, tie to VDD through a 10 kohm pull-up resistor to prevent spurious resets. The OSC1 pin must not float - if using the internal RC oscillator (where supported by configuration bits), tie OSC1 to ground and leave OSC2 unconnected. OTP memory cannot be erased - validate firmware on a JW (windowed) part or PIC16F Flash equivalent before committing to OTP production programming. Brown-out reset is not available on this base PIC16LC54C variant; consider adding external voltage supervision if the supply is unregulated.
Estimated: The PIC16LC54CT-04I/SO GPIO pins have limited drive strength (typical 20 mA source/sink per pin, 100 mA total per port per the Microchip datasheet). For loads exceeding these limits, use a buffer such as ULN2003A (Darlington) for inductive loads or a MOSFET for high-current switching. Keep GPIO trace lengths under 50 mm to minimize ringing when driving cables or capacitive loads. For RC oscillator configurations, use a ceramic resonator with built-in load capacitors rather than a discrete RC network to reduce noise sensitivity and frequency drift across temperature. Add 100 ohm series resistors on GPIO pins that drive off-board connectors to limit ESD and transient current.
Compliance Information
RoHS and lead-free compliance per Microchip product page. NOT AEC-Q100 qualified - this part is not suitable for automotive safety-critical applications; for automotive, use AEC-Q100 qualified PIC16F variants. Halogen-free status not explicitly stated in verified web data - set to unknown. REACH compliance per Microchip general statement.
