PIC16C554T-04/SS - 8-Bit OTP MCU, 896B EPROM, 20-SSOP | Microchip
MPN: PIC16C554T-04/SS ✗ 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 | $1.14 | $1,140.00 |
PIC16C554T-04/SS Overview
A microcontroller (MCU) is a single-chip computer that combines a CPU core, program memory (ROM/Flash/OTP), working RAM, and peripheral interfaces on one silicon die. Within the broader taxonomy, an MCU is a sub-class of microprocessor ICs and a member of the embedded computing family. The PIC16C5xx family, introduced in the early 1990s, uses a 12-bit instruction word RISC core and remains popular for cost-sensitive, deterministic, low-power embedded applications where modern Cortex-M-class parts would be overkill.
Key features of the PIC16C554T-04/SS include a 4 MHz maximum oscillator input with a 200 ns instruction cycle, an 8-bit timer/counter, a watchdog timer (WDT) with on-chip RC oscillator, power-on reset (POR), and power-saving SLEEP mode. The instruction set comprises 33 single-word, single-cycle instructions, and the device supports external oscillator operation with configurable clock modes.
Architecturally, the part uses a Harvard memory layout with separate program and data buses, a two-stage pipeline, and a fixed 8-level hardware stack. Its ultra-compact OTP memory suits low-volume production, prototyping, and legacy design maintenance where code updates are infrequent.
Typical applications include appliance control, sensor interface modules, LED drivers, remote controls, low-end security keypads, and simple motor-control user interfaces. The PIC16C554 family is well suited when a small, proven, deterministic controller is preferred over a larger Flash MCU. Designers should note that the 'T' suffix indicates tape-and-reel packaging, and the 896-byte OTP memory cannot be electrically erased — verified firmware is required before programming.
Drop-in alternatives for PIC16C554T-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 PIC16C554T-04/SS (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, RoHS Status, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C554-04I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C554-04/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C554-20I/SS
✅ Drop-In✓ In Stock
$1.82 / Unit
View Datasheet →PIC16C554T-04I/SS
✅ Drop-In✓ In Stock
$1.09 / Unit
View Datasheet →PIC16C554T-04E/SS
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC16C554T-04/SS Maximum Ratings & Electrical Characteristics
| Architecture | PIC16 8-bit RISC |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 896 B (512 x 14) |
| RAM Size | 80 B |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle | 200 ns |
| Supply Voltage Range | 3.0 V to 5.5 V |
| Number of I/O Pins | 13 |
| Package | 20-pin SSOP (SS) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | 0 C to +70 C (Commercial) |
| Timer/Counters | 1 x 8-bit |
| Watchdog Timer | Yes (on-chip RC oscillator) |
| Power-On Reset | Yes |
| Instruction Set Size | 33 single-word instructions |
| RoHS Status | Compliant |
| Packaging | Tape & Reel (T) |
PIC16C554T-04/SS Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O, Port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O, Port A bit 3 |
| Pin 3 | RA4/T0CKI — Bidirectional I/O / Timer0 clock input |
| Pin 4 | MCLR — Master Clear reset input (active low) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Bidirectional I/O, Port B bit 0 / external interrupt |
| 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 | VSS — Ground reference (secondary) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock in |
| Pin 17 | RA0 — Bidirectional I/O, Port A bit 0 |
| Pin 18 | RA1 — Bidirectional I/O, Port A bit 1 |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (3.0–5.5 V) |
Typical Applications
PIC16C554T-04/SS is suitable for 6 applications: Appliance Control Boards, Remote Control Transmitters, LED Display Drivers, Security Keypads and Access Modules, Sensor Interface Modules, Motor-Control User Interfaces.
Appliance Control Boards
The PIC16C554T-04/SS is well suited to appliance control boards such as washing-machine timers, microwave oven user interfaces, and rice-cooker controllers. Its 896-byte OTP memory holds the small state-machine firmware typical of these designs, and the 13 I/O pins directly drive seven-segment LEDs, keypads, and relay coils without external logic. Each pin sinks up to 25 mA per the Microchip datasheet, eliminating the need for discrete transistor drivers. Compared with a Flash MCU, the OTP cost advantage is meaningful when the firmware is finalized and production volumes exceed tens of thousands of units.
Recommended
Remote Control Transmitters
The PIC16C554T-04/SS fits IR/RF remote-control transmitters where the firmware is fixed and BOM cost dominates. Its 4 MHz oscillator supports 200 ns instruction execution, easily generating standard 38 kHz carrier waveforms for IR modulation. The 80-byte RAM accommodates button-debounce state and transmission buffers, while the SLEEP mode with watchdog wake-up extends battery life in standby. Per the Microchip PIC16C554 datasheet, supply current drops to a few microamps in SLEEP, making the part practical for coin-cell-powered remotes.
Recommended
LED Display Drivers
In LED matrix and seven-segment display drivers, the PIC16C554T-04/SS multiplexes rows and columns using its 13 I/O pins and a software PWM loop. The 200 ns instruction cycle keeps refresh rates above 100 Hz, eliminating visible flicker in 8×8 matrices. Each I/O pin sinks 25 mA directly, so low-current LEDs can be driven without external transistors. For higher-current strings, an external driver such as the ULN2003A is added — the MCU remains the timing master. This architecture is common in scrolling-message signs and indicator panels.
Recommended
Security Keypads and Access Modules
The PIC16C554T-04/SS is widely deployed in low-cost security keypads and access-control modules where deterministic response and OTP firmware protection matter. Its 80-byte RAM stores PIN buffers and debounce state, while the 896-byte OTP holds the authentication logic that is difficult to reverse-engineer compared with Flash. The watchdog timer detects code lockup and resets the MCU, hardening the system against firmware hangs. The 5 V supply also drives backlit keypads directly without level-shifters.
Recommended
Sensor Interface Modules
The PIC16C554T-04/SS serves as a low-cost front-end for sensor interface modules such as thermistor readers, photodiode samplers, and switch-debounce panels. With a 4 MHz clock, it samples digital sensors via polled GPIO at rates exceeding 10 kS/s, suitable for HVAC airflow monitors and water-leak detectors. The integrated watchdog timer resets the MCU on firmware faults, critical in unattended sensor installations. For designs requiring analog inputs, an external ADC such as the MCP3002 can be added over a bit-banged SPI interface.
Recommended
Motor-Control User Interfaces
In small motor-control user-interface panels — such as fan-speed selectors, drill torque dials, and treadmill consoles — the PIC16C554T-04/SS reads encoder inputs and button states, then drives indicator LEDs and low-side MOSFETs via its 25 mA I/O pins. The 4 MHz execution rate handles quadrature decoding and PWM generation for variable-speed drives. Because the firmware is locked in OTP, manufacturers protect calibration constants and proprietary speed curves from end-user modification. The commercial 0 °C to +70 °C grade suits indoor appliance environments.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C554T-04/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C554-04I/SS | PIC16C554-04/SS | PIC16C554-20I/SS | PIC16C554T-04I/SS | PIC16C554T-04E/SS |
|---|---|---|---|---|---|---|
| Package | 20-SSOP (SS) | 20-SSOP (SS) - same | 20-SSOP (SS) - same | 20-SSOP (SS) - same | 20-SSOP (SS) - same | 20-SSOP (SS) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 4 MHz | 4 MHz |
| Program Memory | 896 B OTP | 896 B OTP | 896 B OTP | 896 B OTP | 896 B OTP | 896 B OTP |
| RAM Size | 80 B | 80 B | 80 B | 80 B | 80 B | 80 B |
| Temperature Grade | Commercial 0C to +70C | Industrial -40C to +85C | Commercial 0C to +70C | Industrial -40C to +85C | Industrial -40C to +85C | Extended -40C to +125C |
| Packaging Form | Tape & Reel (T) | Tube | Tube | Tube | Tape & Reel (T) | Tape & Reel (T) |
| Supply Voltage | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V |
Key Differentiators
- Tape-and-reel packaging for high-volume SMT assembly (vs PIC16C554-04/SS)
- Commercial temperature grade optimized for indoor appliances (vs PIC16C554T-04I/SS)
- 4 MHz tuning optimized for deterministic control loops (vs PIC16C554-20I/SS)
Design Notes
The PIC16C554T-04/SS uses OTP EPROM, not Flash — once programmed, the memory cannot be electrically erased. Prototype and validate the firmware on a Flash-based sibling (e.g. PIC16F15344) before committing code to OTP parts. Per the Microchip datasheet, a failed bit can only be re-programmed if the new bit is a '0' (programmed state); reverting to '1' requires UV erase, which the SSOP package does not expose.
Place a 0.1 µF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 20) and a bulk 10 µF electrolytic on the supply rail. The Microchip PIC16C554 datasheet recommends separating analog and digital VDD traces even though the MCU itself is fully digital — this prevents inrush noise from triggering spurious resets on long supply cables in appliance installations.
Keep the 4 MHz crystal or resonator traces between pins 15 (OSC2) and 16 (OSC1) short, surrounded by a grounded guard ring, and away from switching signals. SSOP-20 packages are sensitive to trace crosstalk in the 5 mm vicinity of the oscillator pins. Estimated: at 4 MHz with a 10 MHz edge rate, traces longer than 8 mm may pick up noise that shifts the internal instruction cycle by 5–10 ns.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified — automotive designs must use a qualified PIC16F variant. Halogen-free status not explicitly stated in provided data.
