PIC16C554T-04I/SS - 8-Bit 4MHz OTP MCU 13 I/O 20-SSOP
MPN: PIC16C554T-04I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.62 | $1.62 |
| 10 | $1.49 | $14.90 |
| 100 | $1.34 | $134.00 |
| 500 | $1.21 | $605.00 |
| 1,000 | $1.09 | $1,090.00 |
PIC16C554T-04I/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, data RAM, and peripheral interfaces into one package. The PIC16C family uses a Harvard architecture with separate program and data buses, enabling single-cycle instruction fetch and decode. Within the broader semiconductor hierarchy, the PIC16C554 sits at the bottom of Microchip's mid-range 8-bit lineup, below the enhanced PIC16F and PIC18 families, and is classified as an OTP device - meaning the program memory can be written once and is not re-programmable in-circuit.
Key features include a 35-instruction set optimized for C-compiled code, an on-chip Power-On Reset (POR) circuit, a Watchdog Timer (WDT) for runaway code recovery, a 4 MHz external oscillator interface, and low-power CMOS construction. The 20-SSOP package measures 5.30 mm x 7.20 mm with a 0.65 mm pin pitch, supporting surface-mount assembly on compact boards. Operating voltage is 4.5 V to 5.5 V (industrial spec per Microchip PIC16C554 datasheet), making the part suitable for 5V-only legacy systems.
Architecturally, the PIC16C554 uses a 14-bit instruction word with 8-bit data path, eight-level hardware stack, and two file-select registers (FSR) for indirect addressing. Peripherals are minimal: 13 GPIO, one 8-bit timer/counter, and POR/WDT. The device does not include ADC, UART, or PWM, so designers use software bit-banging or external peripherals for analog and serial functions.
Typical applications include low-cost consumer appliances, white-goods control boards, automotive body modules (non-safety), industrial sensor interfaces, and legacy replacement designs migrating from discrete logic. The industrial temperature grade suits factory-floor and outdoor enclosures. In automotive, prefer the PIC16C554T-04I/SS only for non-safety body electronics; safety-critical systems require AEC-Q100 qualified parts.
When designing, note that OTP memory cannot be field-updated - plan firmware revisions carefully. The 4 MHz maximum clock restricts instruction throughput for math-intensive loops, and the 80-byte RAM limits stack depth and buffer sizes. Designers should use the MPLAB IDE with a Hi-Tech PICC or XC8 compiler.
This page synthesizes distributor pricing, drop-in pin-compatible alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C554T-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 PIC16C554T-04I/SS (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Watchdog Timer, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C554T-04E/SS
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC16C554T-04/SS
✅ Drop-In✓ In Stock
$1.14 / Unit
View Datasheet →PIC16C554-20I/SS
✅ Drop-In✓ In Stock
$1.82 / Unit
View Datasheet →PIC16C554-04I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C554T-04/SO
✅ Drop-In✓ In Stock
$1.15 / Unit
View Datasheet →PIC16C554T-04I/SS Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC 16C |
| Core Processor | PIC |
| Core Size | 8-Bit |
| Maximum Clock Speed | 4 MHz |
| Instruction Cycle Time | 200 ns |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 896 B (512 x 14 words) |
| Data RAM Size | 80 B |
| I/O Pins | 13 |
| Supply Voltage (Vdd) | 4.5 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 20-SSOP |
| Mounting Type | Surface Mount |
| Peripherals | POR, WDT |
| Oscillator Type | External |
| Number of Instructions | 35 |
| Packaging | Tape & Reel |
| RoHS Status | Compliant |
PIC16C554T-04I/SS Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / Programming voltage |
| Pin 2 | RA0 — Port A bit 0 (digital I/O) |
| Pin 3 | RA1 — Port A bit 1 (digital I/O) |
| Pin 4 | RA2 — Port A bit 2 (digital I/O) |
| Pin 5 | RA3 — Port A bit 3 (digital I/O) |
| Pin 6 | RA4 — Port A bit 4 (digital I/O, open-drain) |
| Pin 7 | VSS — Ground reference |
| Pin 8 | OSC1/CLKIN — External oscillator input / clock in |
| Pin 9 | OSC2/CLKOUT — External oscillator output / clock out |
| Pin 10 | RC0 — Port C bit 0 (digital I/O) |
| Pin 11 | RC1 — Port C bit 1 (digital I/O) |
| Pin 12 | RC2 — Port C bit 2 (digital I/O) |
| Pin 13 | RC3 — Port C bit 3 (digital I/O) |
| Pin 14 | RC4 — Port C bit 4 (digital I/O) |
| Pin 15 | RC5 — Port C bit 5 (digital I/O) |
| Pin 16 | RC6 — Port C bit 6 (digital I/O) |
| Pin 17 | RC7 — Port C bit 7 (digital I/O) |
| Pin 18 | VDD — Positive supply voltage (4.5V-5.5V) |
| Pin 19 | RB0/INT — Port B bit 0 / External interrupt |
| Pin 20 | RB7 — Port B bit 7 (digital I/O) |
Typical Applications
PIC16C554T-04I/SS is suitable for 6 applications: Low-Cost Consumer Appliance Control, Industrial Sensor Interface Module, Automotive Body Electronics (Non-Safety), Legacy Board Replacement (Cost-Down), Battery-Backed Sensor Hub, Educational & Development Platform.
Low-Cost Consumer Appliance Control
The PIC16C554T-04I/SS fits white-goods and small-appliance controllers where BOM cost dominates and firmware is fixed. Its 896-byte OTP memory is sufficient for typical appliance state machines (relay sequencing, button debounce, LED indication) while the 4 MHz clock handles simple timing loops. The 13 GPIO pins drive triac interfaces, mechanical relays, and segment LEDs without external mux. Industrial temperature grade (-40C to +85C) tolerates kitchen and laundry environments.
Recommended
Industrial Sensor Interface Module
For factory-floor sensor aggregation nodes, the PIC16C554T-04I/SS reads digital sensors and bit-bangs UART/I2C to a higher-level controller. Its 4 MHz core executes 200 ns per instruction - fast enough for 9600 baud UART in software without hardware overhead. The 80-byte RAM buffers short sensor packets, and the Watchdog Timer recovers from EMI-induced lockups common in industrial settings. Industrial temp grade survives -40C cold-start in unheated enclosures.
Recommended
Automotive Body Electronics (Non-Safety)
The PIC16C554T-04I/SS controls non-safety automotive loads such as interior lighting, seat position memory, and accessory timers. Its 4 MHz clock is adequate for these slow response-time applications, and the 13 GPIO drive LED drivers and small relays. The industrial temperature grade handles cabin and under-hood proximity. Note: this part is NOT AEC-Q100 qualified; for safety-critical applications choose AEC-Q100 parts like PIC16F15344-I/SS.
Recommended
Legacy Board Replacement (Cost-Down)
When modernizing a legacy 8051 or PIC16C design, the PIC16C554T-04I/SS is the lowest-cost 5V 8-bit MCU that drops into existing 20-SSOP footprints. Its 35-instruction RISC architecture simplifies code migration from older PIC16C5x parts, and the 4 MHz cycle keeps firmware timing identical. The OTP memory is acceptable for end-of-life products where firmware will never change. Industrial temp grade maintains backward compatibility with existing field deployments.
Recommended
Battery-Backed Sensor Hub
The PIC16C554T-04I/SS can act as a low-cost wake-up controller in battery-backed sensor hubs, where it polls a sensor and decides whether to wake the main MCU. The 4 MHz core provides fast wake-and-decide cycles, and the 80-byte RAM stores the last sensor reading for the main processor. While the PIC16C554 lacks sleep modes of newer parts, its low static current at 4 MHz and 5V is acceptable for mains-backed or large-battery applications. Industrial temp grade tolerates outdoor enclosures.
Recommended
Educational & Development Platform
Universities and training programs use the PIC16C554T-04I/SS to teach 8-bit embedded fundamentals because its 35-instruction RISC architecture is approachable and the 896-byte program memory fits within a single textbook chapter. The 20-SSOP package is breadboard-friendly with adapter boards, and the 4 MHz execution rate lets students observe instruction cycles with a logic analyzer. While OTP makes student re-programs impossible, PIC16F554 adapters provide a flash alternative for lab work.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C554T-04I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C554T-04E/SS | PIC16C554T-04/SS | PIC16C554-20I/SS | PIC16C554-04I/SS |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-SSOP | 20-SSOP | 20-SSOP | 20-SSOP | 20-SSOP |
| Maximum Clock Speed | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 4 MHz |
| Program Memory | 896 B OTP | 896 B OTP | 896 B OTP | 896 B OTP | 896 B OTP |
| Data RAM | 80 B | 80 B | 80 B | 80 B | 80 B |
| Temperature Grade | Industrial (-40C to +85C) | Extended Commercial (0C to +70C) | Commercial (0C to +70C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) |
| I/O Pins | 13 | 13 | 13 | 13 | 13 |
| Packaging Form | Tape & Reel | Tape & Reel | Tape & Reel | Tape & Reel | Tube |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
Key Differentiators
- Industrial temperature grade (-40C to +85C) in 20-SSOP (vs PIC16C554T-04E/SS)
- 4 MHz speed grade optimizes cost for slow-control applications (vs PIC16C554-20I/SS)
- Tape & Reel packaging for SMT production (vs PIC16C554-04I/SS)
Design Notes
Estimated: at 4 MHz, 5.0 V, and 25 C, the PIC16C554T-04I/SS draws approximately 2-5 mA active current per Microchip datasheet DS30214G. The device has no internal voltage regulator, so VDD must be tightly regulated to 4.5-5.5 V with a 100 nF decoupling cap adjacent to pin 18 (VDD) and a 10 uF bulk cap on the board. For battery applications, the lack of sleep modes makes this MCU unsuitable; migrate to PIC16LF1554-I/SS instead.
OTP memory can be programmed only ONCE - a programming error bricks the device permanently. Always use a socketed programmer and verify firmware on a flash-based PIC16F554-I/SS before committing to OTP production parts. Per the Microchip PIC16C554 datasheet, VPP (MCLR pin) must be raised to ~13V during programming; ensure your programmer supports this. Brown-out detection is NOT included in the PIC16C554, so add external voltage monitoring if the application is sensitive to low-Vdd lockups.
Route the 4 MHz external oscillator traces (OSC1 pin 8, OSC2 pin 9) as short as possible, with a ground guard ring around the crystal/oscillator to suppress EMI. The MCLR/VPP pin (1) requires a 10 kohm pull-up to VDD for normal operation and a 100 nF cap to ground for noise filtering - the cap slows the rise of MCLR and prevents false resets. Place decoupling caps within 5 mm of the VDD/VSS pins, with vias to an internal ground plane.
Compliance Information
RoHS compliant per Microchip product page; lead-free 20-SSOP with matte-tin plating. REACH, halogen-free, and conflict-minerals status not stated in verified data - consult Microchip for current declarations. NOT AEC-Q100 qualified; for automotive safety choose AEC-Q100 graded parts.
