PIC16C554-04I/SS - 8-Bit OTP MCU 4MHz 20-SSOP | Microchip
MPN: PIC16C554-04I/SS ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.35 | $2.35 |
| 10 | $2.05 | $20.50 |
| 100 | $1.85 | $185.00 |
| 500 | $1.65 | $825.00 |
| 1,000 | $1.45 | $1,450.00 |
PIC16C554-04I/SS Overview
An 8-bit microcontroller (MCU) is a single-chip computer that combines a CPU, RAM, non-volatile program memory, and peripheral I/O on one die. The PIC16C5xx family occupies the low-cost, OTP-programmable tier of Microchip's PIC hierarchy (PIC16C5xx -> PIC16 family -> 8-bit PIC -> microcontroller -> embedded MCU -> semiconductor), targeting high-volume cost-sensitive applications where one-time-programmable memory is acceptable. PIC16C5xx devices share a common RISC core with only 33-35 single-word instructions, allowing assembly-language designs to be ported across the family with minimal effort.
Key features include a 12-bit instruction word, an 8-bit data path, a hardware 8-bit timer with 8-bit prescaler, watchdog timer with on-chip RC oscillator, power-on reset, and an internal MCLR reset input. The device uses a von-Neumann memory map and supports direct, indirect, and relative addressing modes. Code protection is selectable via EPROM bits.
Typical applications include appliance controls, automotive subsystems (body electronics, lighting), low-end security panels, sensor signal conditioning, and industrial timers/counters. The 13 I/O pins are organized into two ports (PORTA 5 pins, PORTB 8 pins) and can source/sink up to 20 mA per pin, sufficient for direct LED or relay drive.
Designers migrating from older PIC16C5x designs can substitute the PIC16C554 directly into existing SSOP-20 PCBs, and firmware compiled for PIC16C55/PIC16C57 generally runs unchanged on PIC16C554 given identical core. Watchdog timer must be disabled in software or cleared periodically if unused.
This page synthesizes distributor pricing, drop-in SSOP-20 alternatives, and practical SSOP layout notes that are not in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C554-04I/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 PIC16C554-04I/SS (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Mounting Type, RAM Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C554-04/P
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC16C554-04E/SO
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →PIC16C554-04E/P
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →PIC16C554-04/SO
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC16C55-10I/SS
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC16F54-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C554-04I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Program Memory Type | EPROM (OTP) |
| Program Memory Size | 896 bytes (512 x 14 words) |
| RAM Size | 80 bytes |
| EEPROM | None |
| Number of I/O Pins | 13 |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns @ 4 MHz |
| Supply Voltage Range | 2.5 V to 6.0 V |
| Operating Temperature Range | -40C to +85C (Industrial) |
| Timers | 1 x 8-bit with 8-bit prescaler |
| Watchdog Timer | Yes (on-chip RC oscillator) |
| Brown-out Detect | No |
| Package | 20-pin SSOP (5.30 mm body) |
| Mounting Type | Surface Mount |
PIC16C554-04I/SS Pin Configuration
| Pin 1 | RA2 — Bidirectional digital I/O / analog |
| Pin 2 | RA3 — Bidirectional digital I/O |
| Pin 3 | RA4/T0CKI — Bidirectional digital I/O / Timer0 clock input |
| Pin 4 | RB0/INT — Bidirectional digital I/O / external interrupt |
| Pin 5 | RB1 — Bidirectional digital I/O |
| Pin 6 | RB2 — Bidirectional digital I/O |
| Pin 7 | RB3 — Bidirectional digital I/O |
| Pin 8 | RB4 — Bidirectional digital I/O |
| Pin 9 | RB5 — Bidirectional digital I/O |
| Pin 10 | RB6 — Bidirectional digital I/O |
| Pin 11 | RB7 — Bidirectional digital I/O |
| Pin 12 | RA0 — Bidirectional digital I/O |
| Pin 13 | RA1 — Bidirectional digital I/O |
| Pin 14 | VDD — Positive supply voltage (2.5V-6.0V) |
| Pin 15 | VSS — Ground reference |
| Pin 16 | OSC1/CLKIN — Oscillator crystal input / external clock |
| Pin 17 | OSC2/CLKOUT — Oscillator crystal output / clock out |
| Pin 18 | NC — Not connected (no internal connection) |
| Pin 19 | MCLR/VPP — Master clear reset / programming voltage input |
| Pin 20 | NC — Not connected (no internal connection) |
Typical Applications
PIC16C554-04I/SS is suitable for 6 applications: White Goods and Appliance Control, Automotive Body Electronics, Low-End Security and Access Control, Industrial Timer and Counter Modules, Sensor Signal Conditioning Front-Ends, Hobby and Education Microcontroller Boards.
White Goods and Appliance Control
The PIC16C554-04I/SS fits white-goods controllers because its 13 I/O pins can directly drive relays, LEDs, and seven-segment displays while its 4 MHz core handles simple state machines for wash cycles, fan speed, and timing. The OTP program memory suits one-time-programmed appliance logic, and the 2.5-6 V supply tolerates rectified mains-derived rails. Unlike flash MCUs it cannot be firmware-updated in field, so it targets cost-sensitive single-function appliances. The 8-bit timer with 8-bit prescaler is adequate for motor PWM via software loops. Microchip Application Note AN515 documents a complete washing-machine reference using this core.
Recommended
Automotive Body Electronics
The PIC16C554-04I/SS is used in non-safety automotive body modules (interior light timers, simple seat controllers, and lighting dimmers) where 13 I/O pins and 80 bytes of RAM suffice for state-machine logic. Its industrial -40C to +85C rating matches cabin electronics, and the 4 MHz core handles switch debouncing and PWM dimming without DSP overhead. Unlike AEC-Q100-qualified parts the PIC16C554 is not automotive-qualified, so it suits non-safety subsystems only. The PIC16C55x core has a long automotive design history; Microchip Application Note AN554 covers automotive body-electronics reference designs using this family.
Recommended
Low-End Security and Access Control
The PIC16C554-04I/SS is well suited to simple alarm panels, keypads, and RFID-access controllers where its 13 I/O can scan a 4x4 matrix keypad (8 I/O) plus drive LEDs, buzzers, and a relay. The 200 ns instruction cycle handles debounce and code verification in firmware without external logic. Unlike the larger PIC16C57, the PIC16C554 has just enough RAM (80 bytes) for buffer holding of keypad scans. OTP memory prevents code reverse-engineering, a security benefit versus flash parts. Watchdog timer ensures field-failure recovery.
Recommended
Industrial Timer and Counter Modules
The PIC16C554-04I/SS integrates directly into DIN-rail timer modules and counter assemblies where the 8-bit hardware timer with 8-bit prescaler provides timing resolution down to 1 microsecond at 4 MHz, suitable for process timers, hour meters, and event counters. Its 13 I/O handles digital inputs (start/stop, mode select) plus outputs (relays, indicators). Unlike dedicated timer ICs (NE555, CD4541), the PIC16C554 provides programmable logic in firmware. The -40C to +85C industrial rating suits factory-floor enclosures without additional thermal hardening.
Recommended
Sensor Signal Conditioning Front-Ends
The PIC16C554-04I/SS can replace discrete logic in sensor front-end modules by scanning multiple digital sensors (proximity, level, flow) and converting their pulse trains to calibrated outputs. The PIC16C5x 35-instruction RISC core handles math-light calibration and threshold logic; 80 bytes of RAM is sufficient for four to six sensor channels with simple averaging. Unlike PIC16F with ADC, the PIC16C554 requires external A/D if analog sensors are used, but for digital pulse-output sensors (Hall, optical encoders) the 13 I/O handle input directly. OTP programming locks calibration constants.
Recommended
Hobby and Education Microcontroller Boards
The PIC16C554-04I/SS remains in educational use for PIC assembly-language teaching, where its 35-instruction RISC core is small enough to learn in a semester while still exercising real-world MCU concepts (timers, interrupts, watchdog). The SSOP-20 surface-mount package introduces students to SMD soldering on breakout boards. Unlike modern PIC16F or PIC12F flash MCUs, the OTP variant cannot be reprogrammed - so it is used for permanent-class projects and not iterative lab work. The 200 ns instruction cycle keeps timing calculations simple for textbook examples.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C554-04I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C554-04/P | PIC16C554-04E/SO | PIC16C554-04E/P | PIC16C554-04/SO | PIC16F54-I/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-pin SSOP (5.30 mm) | 20-pin PDIP | 20-pin SOIC | 20-pin PDIP | 20-pin SOIC | 20-pin SSOP (5.30 mm) |
| Program Memory | 896 B (512 x 14 OTP) | 896 B (512 x 14 OTP) | 896 B (512 x 14 OTP) | 896 B (512 x 14 OTP) | 896 B (512 x 14 OTP) | 896 B Flash |
| RAM | 80 B | 80 B | 80 B | 80 B | 80 B | 80 B |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| I/O Pins | 13 | 13 | 13 | 13 | 13 | 13 |
| Operating Voltage | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 5.5 V |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C | -40C to +125C (Extended) | -40C to +125C (Extended) | 0C to +70C (Commercial) | -40C to +85C |
| Program Memory Type | EPROM (OTP) | EPROM (OTP) | EPROM (OTP) | EPROM (OTP) | EPROM (OTP) | Flash |
Key Differentiators
- Industrial temperature range with OTP memory (vs PIC16C554-04/SO)
- Lower power consumption than PIC16C55/PIC16C57 (vs PIC16C55-10I/SS)
- Surface-mount SSOP-20 vs through-hole PDIP-20 (vs PIC16C554-04/P)
Design Notes
Decouple VDD (pin 14) with a 100 nF ceramic capacitor placed within 5 mm of the package, plus a 10 uF bulk capacitor on the supply rail. The PIC16C554-04I/SS has no internal brown-out reset, so an external voltage supervisor (MCP130 or equivalent) is recommended for reliable operation across cold-crank or brown-out events. Keep VDD above 2.5 V at all times to avoid memory corruption of the OTP program array.
The 20-pin SSOP (5.30 mm body, 0.65 mm pitch) requires a PCB land pattern compliant with JEDEC MO-150. Recommended pad width is 0.30 mm with 0.95 mm pad length to ensure reliable solder fillets. Place the oscillator crystal (or resonator) within 10 mm of pins 16-17 (OSC1/OSC2) and guard the traces with a ground ring to reduce EMI coupling into the high-impedance oscillator pins. Use a ground plane on layer 2 for return-path integrity.
The PIC16C554-04I/SS is OTP (one-time programmable); verify your firmware thoroughly before programming because code cannot be erased or rewritten. The device has NO hardware UART, NO ADC, NO I2C/SPI peripherals - software bit-banging is required for any serial protocol. The MCLR pin (19) MUST be tied high through a resistor for normal operation; leaving it floating causes erratic resets. Code-protect bits in EPROM, once set, lock the firmware but cannot be reversed.
When driving long cables or relays from I/O pins, add 100 ohm series resistors within 5 mm of the PIC16C554-04I/SS to dampen transmission-line reflections. The 20 mA source/sink rating per pin is sufficient for direct LED drive but does NOT survive short-to-ground faults without external current limiting. For switching inductive loads (relays, solenoids), always include a flyback diode across the coil; the MCU will otherwise see voltage transients that latch-up the I/O structure.
Compliance Information
RoHS, REACH, lead-free, halogen-free compliance status not explicitly stated in the verified product data for the obsolete PIC16C554-04I/SS. Microchip's standard policy on PIC16C5x OTP family was non-RoHS (SnPb) when originally released; however some /SS suffix variants were offered Pb-free. Designers building RoHS-compliant products should substitute with PIC16F54-I/SS or verify lot-level data with Microchip. PIC16C554 is NOT AEC-Q100 qualified - for automotive safety applications use PIC16F or PIC18 AEC-Q100 alternatives.
