PIC16LC54CT-04/SS - 4MHz 8-Bit OTP MCU 20-SSOP | Microchip
MPN: PIC16LC54CT-04/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.42 | $2.42 |
| 10 | $2.18 | $21.80 |
| 100 | $1.94 | $194.00 |
| 500 | $1.74 | $870.00 |
| 1,000 | $1.55 | $1,550.00 |
PIC16LC54CT-04/SS Overview
A baseline PIC microcontroller is an 8-bit RISC MCU from Microchip's PIC16C5X family, the lowest-cost tier of the PIC architecture. PIC microcontrollers are single-chip computers containing a CPU, ROM/EPROM/Flash program memory, RAM, and I/O peripherals in one package. PIC MCUs sit within the broader taxonomy of microcontrollers -> embedded processors -> semiconductor devices. The PIC16C5X baseline family uses 12-bit-wide opcodes that achieve roughly 2:1 code compression over competing 8-bit MCUs, allowing denser functionality in smaller program memory footprints.
Key features include 12 bidirectional I/O pins, a Power-On Reset (POR) circuit, an independent Watchdog Timer (WDT) with its own on-chip RC oscillator, and a code-protection bit. The device offers a 33-instruction set with 2:1 code compression and a two-stack-deep subroutine return stack. The WDT improves reliability in unattended or electrically noisy environments, while the POR eliminates external reset circuitry in many designs.
The PIC16C5X architecture uses a Harvard-design RISC core with separate program and data buses. The OTP program memory is programmed once with a device programmer and cannot be erased, which suits low-cost, high-volume production. The 12-bit instruction width is unusually wide for an 8-bit MCU and is the reason the 768-byte memory holds 512 instructions. OTP occupies a niche between mask-ROM (cheapest, longest lead time) and Flash (reprogrammable, higher cost).
Typical applications include low-cost consumer appliances, battery-powered handheld devices, simple sensor interfaces, automotive body controllers, and industrial timer/replacement-logic modules. The commercial temperature range and 4 MHz clock make it suitable for non-real-time control tasks where deterministic behavior and minimal BOM cost matter more than computational throughput.
When designing with this device, note that OTP memory cannot be field-updated. Plan firmware revision control carefully, or consider a Flash-based sibling such as the PIC16F54 for engineering builds. The 20-SSOP package requires standard surface-mount assembly; the WDT should be enabled in any product where firmware lockup would create a safety or operational hazard.
This page synthesizes Microchip datasheet specifications, verified distributor pricing, drop-in SSOP-packaged pin-to-pin replacements, and practical design notes for baseline PIC embedded designs not consolidated elsewhere.
Drop-in alternatives for PIC16LC54CT-04/SS — 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-04/SS (same form factor and footprint) — differing in Watchdog Timer, Package, Program Memory Size, Program Memory Type, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC54C-04/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC54AT-04/SS
✅ Drop-In✓ In Stock
$0.86 / Unit
View Datasheet →PIC16LC54A-04/SS
✅ Drop-In✓ In Stock
$3.85 / Unit
View Datasheet →PIC16LC54C-04I/P
✅ Drop-In✓ In Stock
$2.31 / Unit
View Datasheet →PIC16LC54AT-04I/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC16LC54CT-04/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C5X baseline, 8-bit RISC |
| Program Memory | 768 B (512 x 12) OTP |
| Data RAM | 25 B (25 x 8) |
| Maximum Clock Frequency | 4 MHz |
| Operating Voltage Range (LC) | 2.5 V to 6.25 V |
| I/O Pins | 12 bidirectional |
| Instruction Set | 33 instructions, 12-bit wide |
| Subroutine Stack | 2 levels |
| Watchdog Timer | Yes, independent on-chip RC oscillator |
| Power-On Reset | Yes |
| Code Protection | Yes (security fuse) |
| Package | 20-SSOP (5.30 mm body, 0.65 mm pitch) |
| Mounting Type | Surface Mount |
| Lead-Free / RoHS | Lead-free finish (verify lot, legacy part) |
| Temperature Grade | Commercial |
PIC16LC54CT-04/SS Pin Configuration
| Pin 1 | RA0 — Port A bit 0 (bidirectional digital I/O) |
| Pin 2 | RA1 — Port A bit 1 (bidirectional digital I/O) |
| Pin 3 | RA2 — Port A bit 2 (bidirectional digital I/O) |
| Pin 4 | RA3 — Port A bit 3 (bidirectional digital I/O) |
| Pin 5 | RB0 — Port B bit 0 (bidirectional digital I/O) |
| Pin 6 | RB1 — Port B bit 1 (bidirectional digital I/O) |
| Pin 7 | RB2 — Port B bit 2 (bidirectional digital I/O) |
| Pin 8 | RB3 — Port B bit 3 (bidirectional digital I/O) |
| Pin 9 | RB4 — Port B bit 4 (bidirectional digital I/O) |
| Pin 10 | RB5 — Port B bit 5 (bidirectional digital I/O) |
| Pin 11 | RB6 — Port B bit 6 (bidirectional digital I/O) |
| Pin 12 | RB7 — Port B bit 7 (bidirectional digital I/O) |
| Pin 13 | OSC1 — Oscillator input (XT/RC/HS mode) |
| Pin 14 | OSC2 — Oscillator output (crystal mode) |
| Pin 15 | /MCLR — Master Clear reset input (active low) |
| Pin 16 | VSS — Ground reference |
| Pin 17 | VDD — Positive supply voltage (2.5 V to 6.25 V) |
| Pin 18 | NC — Not connected (reserved) |
| Pin 19 | NC — Not connected (reserved) |
| Pin 20 | NC — Not connected (reserved) |
Typical Applications
PIC16LC54CT-04/SS is suitable for 6 applications: Low-Cost Consumer Appliance Controllers, Battery-Powered Handheld Devices, Automotive Body Electronics, Industrial Timer and Replacement-Logic Modules, Simple Sensor Interface Modules, Educational and Hobby Embedded Projects.
Low-Cost Consumer Appliance Controllers
The PIC16LC54CT-04/SS is ideal for low-cost consumer appliances such as coffee makers, rice cookers, toaster ovens, and simple kitchen timers where BOM cost dominates design decisions. With 768 bytes of OTP memory and 12 I/O pins, it can read a keypad, drive an LED or 7-segment display, and control a relay or TRIAC for heater or motor switching. The 2.5 V to 6.25 V supply range enables direct connection to 3-cell alkaline or 5 V wall-adapter power without a separate regulator. The integrated Watchdog Timer recovers the appliance automatically if firmware lockup occurs, an essential feature for unattended consumer products. Compared with Flash MCUs in the same price tier, the OTP PIC16LC54C delivers lower per-unit cost in high-volume production runs (100k+ units), which is the typical breakeven point for OTP-based designs.
Recommended
Battery-Powered Handheld Devices
The PIC16LC54CT-04/SS suits battery-powered handheld devices such as remote controls, simple toys, IR transmitters, and personal-care tools. The LC low-voltage variant operates down to 2.5 V, enabling direct operation from two AA alkaline cells without a boost converter, which maximizes runtime and minimizes BOM cost. The 4 MHz clock and 33-instruction RISC core deliver deterministic execution of timing-critical tasks like IR carrier generation (typically 38 kHz) within tight interrupt latency. At full 4 MHz operation the part draws only a few mA active and microamps in sleep mode, supporting months of standby life on primary cells. The 12 I/O pins are sufficient to scan a 3x4 keypad matrix and drive status LEDs with no external logic. The OTP memory prevents accidental firmware modification in the field, which is desirable for safety-critical or regulatory-certified products.
Recommended
Automotive Body Electronics
The PIC16LC54CT-04/SS (commercial temperature grade) is suitable for non-safety automotive body electronics such as interior lighting controllers, window-lift timers, seat-heater switches, and accessory delay modules. The Watchdog Timer and Power-On Reset provide robustness against automotive electrical transients, while the wide 2.5 V to 6.25 V supply tolerance accommodates cranking and load-dump events (with external TVS protection). The 4 MHz core is sufficient for sequencing relay outputs, debouncing switches, and generating PWM dimming signals. For under-hood or safety-critical applications requiring -40C to +125C operation, the PIC16LC54CT-04I/SS industrial-temperature variant is pin-to-pin compatible and may be substituted directly. The OTP memory format prevents field tampering with calibration or vehicle security firmware, an advantage for OEM production programming.
Recommended
Industrial Timer and Replacement-Logic Modules
The PIC16LC54CT-04/SS is well suited to industrial timer modules, sequence controllers, and CMOS- or TTL-replacement logic boards where a single low-cost MCU can replace dozens of discrete logic ICs. The 2:1 code compression of the 12-bit PIC instruction word lets a small OTP footprint absorb what would otherwise require 74HC-series gates, latches, and counters. Industrial control panels, conveyor segment timers, and pump-cycle controllers benefit from the deterministic instruction timing and integrated WDT for unattended operation. The 20-SSOP package fits into compact DIN-rail enclosures, and the commercial temperature range covers most factory-floor cabinets. For harsher industrial environments, the industrial-temperature PIC16LC54AT-04I/SS is pin-to-pin compatible and supports the same SSOP-20 footprint, allowing the same PCB to be populated with either grade depending on the deployment.
Recommended
Simple Sensor Interface Modules
The PIC16LC54CT-04/SS works well as a front-end interface MCU for simple sensor modules including thermistor readers, photocell light sensors, contact-debounce inputs, and basic pulse counters. The 12-bit instruction set and 4 MHz clock enable 10-bit equivalent ADC-free measurement by integrating RC-charge timing through the I/O pins, eliminating an external ADC IC. The 25 bytes of RAM can buffer a small moving-average filter for noise rejection, and the 768-byte OTP holds lookup tables for linearization (thermistor Steinhart-Hart, photocell lux curves). The integrated Power-On Reset prevents false readings at startup, which is critical for sensors feeding alarms or control loops. Low active and sleep currents support battery-powered wireless sensor nodes where the MCU spends most of its time in sleep, waking periodically to take a measurement.
Recommended
Educational and Hobby Embedded Projects
The PIC16LC54CT-04/SS serves as a low-cost teaching platform for introductory microcontroller courses, hobby electronics, and maker projects where the goal is learning 8-bit embedded programming fundamentals without the complexity of modern peripherals. The 33-instruction RISC instruction set is small enough to teach assembly in a single lab session, and the 2-level hardware stack forces students to write iterative rather than deeply-nested code. The OTP constraint teaches production-engineering discipline: code must be debugged in a simulator before committing to the part. The 20-SSOP package is breadboard-friendly with an SSOP-to-DIP adapter. For hobby prototyping where Flash reprogrammability is needed, the PIC16F54-I/SS shares the SSOP-20 footprint and PIC16C5X instruction set, enabling students to develop code on Flash parts and migrate to OTP PIC16LC54C for cost-optimized final builds.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC54CT-04/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC54C-04/SS | PIC16LC54AT-04/SS | PIC16LC54A-04/SS | PIC16LC54C-04I/P | PIC16LC54AT-04I/SO |
|---|---|---|---|---|---|---|
| Package | 20-SSOP (0.65 mm pitch) | 20-SSOP (same) | 20-SSOP (same) | 20-SSOP (same) | 20-PDIP (different footprint) | 20-SOIC (1.27 mm pitch, different footprint) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | PIC16C5X baseline, 8-bit RISC | PIC16C5X baseline (same) | PIC16C5X with "A" extensions | PIC16C5X with "A" extensions | PIC16C5X baseline (same) | PIC16C5X with "A" extensions |
| Program Memory | 768 B (512 x 12) OTP | 768 B OTP (same) | 768 B OTP (same) | 768 B OTP (same) | 768 B OTP (same) | 768 B OTP (same) |
| Maximum Clock | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Supply Voltage Range | 2.5 V to 6.25 V (LC) | 2.5 V to 6.25 V | 2.5 V to 6.25 V | 2.5 V to 6.25 V | 2.5 V to 6.25 V | 2.5 V to 6.25 V |
| Temperature Grade | Commercial (0C to +70C) | Commercial | Commercial | Commercial | Industrial (-40C to +85C) | Industrial (-40C to +85C) |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| Watchdog Timer | Yes (independent RC osc) | Yes (same) | Yes (same) | Yes (same) | Yes (same) | Yes (same) |
Key Differentiators
- Lowest-cost 8-bit MCU in the PIC16C5X baseline family with tape-and-reel packaging (vs PIC16LC54C-04/SS)
- Low-voltage LC variant operates down to 2.5 V for 2-cell battery designs (vs PIC16C54C-04/SS)
- Commercial temperature grade optimized for indoor consumer/industrial applications (vs PIC16LC54CT-04I/SS)
- OTP memory prevents accidental firmware modification in the field (vs PIC16F54-I/SS)
Design Notes
PIC16LC54CT-04/SS uses OTP (One-Time Programmable) memory, which cannot be erased or rewritten once programmed. A firmware bug locked into OTP cannot be patched in the field - only by replacing the physical part. Always fully validate firmware on a Flash-based equivalent (e.g., PIC16F54-I/SS) before committing to OTP production programming. Plan for at least one firmware spin before production release. The configuration word (oscillator type, WDT enable, code protection) is also OTP and must be set correctly on the first programming pass.
Add a 0.1 uF ceramic decoupling capacitor as close as possible to the VDD pin (pin 17), with a short ground return to the nearest VSS pin (pin 16). The PIC16C5X core is sensitive to VDD ripple during clock-edge transitions; inadequate decoupling can cause intermittent code-execution failures that mimic firmware bugs. For battery-powered designs with long wire harnesses, add a 10 uF bulk capacitor at the MCU supply pin to absorb battery-voltage transients during load steps (relay activation, motor start). The /MCLR pin (pin 15) should be pulled up to VDD through a 10 kohm resistor to ensure proper Power-On Reset.
The PIC16LC54CT-04/SS in 20-SSOP has a thermal resistance (theta_JA) of approximately 100 C/W. At maximum active current (about 2 mA at 4 MHz, 5 V), power dissipation is roughly 10 mW, resulting in a junction temperature rise of only 1 C above ambient. Thermal management is not a concern for this part in normal commercial applications. However, in enclosed industrial enclosures with no airflow, ambient temperature can rise to +50 C or higher; verify the commercial-temperature upper limit (typically +70 C) is not exceeded. Substitute the industrial-temperature variant (PIC16LC54CT-04I/SS) if higher ambient temperatures are expected.
Route the oscillator traces (OSC1 pin 13 and OSC2 pin 14) as short and direct as possible, with a ground guard ring around the crystal or resonator. Keep oscillator traces away from high-current switching traces (relay coils, TRIAC drivers) to prevent injection of noise into the clock signal. For RC-oscillator mode, place the R and C components within 5 mm of the OSC1 pin to minimize parasitic capacitance. The /MCLR trace should also be kept short and direct, with the pull-up resistor placed close to the /MCLR pin, not at the supply rail end of the trace, to maximize noise immunity.
Compliance Information
Lead-free (Pb-free) finish per Microchip product page. The PIC16LC54C family predates mandatory RoHS transitions; verify lot-level RoHS compliance certificate if required for EU export. Halogen-free status not explicitly published; treat as unknown unless declared on the shipment paperwork. AEC-Q100 not applicable - PIC16LC54C is not qualified for automotive safety applications; for automotive use, choose PIC16LC54CT-04I/SS industrial-temperature variant.
