PIC16C554-04E/SS - 4MHz 8-Bit OTP MCU, 20-SSOP | Microchip
MPN: PIC16C554-04E/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.95 | $3.95 |
| 10 | $3.55 | $35.50 |
| 100 | $3.1 | $310.00 |
| 500 | $2.7 | $1,350.00 |
| 1,000 | $2.35 | $2,350.00 |
PIC16C554-04E/SS Overview
What is an OTP microcontroller? An OTP (One-Time-Programmable) microcontroller is a class of MCU whose program memory can be written only once after manufacture, typically using EPROM cells exposed through a programming window or via ICSP. OTP MCUs sit between fully-mask-ROM parts (lowest unit cost, but require a full production mask) and Flash-based MCUs (re-programmable, higher die cost). They are widely used in cost-sensitive, high-volume consumer and industrial products where firmware is finalized at design lock and re-programmability is not required. Architecturally, the PIC16C554 belongs to the PIC16C family: RISC-based 8-bit core, single accumulator (W), Harvard memory map, 12-bit (or 14-bit for PIC16C55x) instruction width, and 35 single-word instructions.
Key differentiating features of the PIC16C554-04E/SS include its 13 general-purpose digital I/O pins, integrated Power-on Reset (POR), Watchdog Timer (WDT) with on-chip RC oscillator, and a wide 3.0 V to 5.5 V operating voltage range (PIC16C554-04 variant). The "E" temperature-grade suffix denotes the -40 °C to +125 °C automotive/extended industrial range, while the "04" speed designator specifies the 4 MHz maximum oscillator frequency. The 20-SSOP package (JEDEC MO-150, 5.30 mm body) provides a low-profile surface-mount footprint with gull-wing leads for high-yield automated assembly.
Architecturally, the PIC16C554 uses Microchip's classic PIC RISC core with a two-stage pipeline, dedicated hardware stack (2 levels for this family), and a 14-bit wide instruction word that allows single-cycle opcode fetch and execute. The ALU operates on the working register (W) plus any file register; bit-oriented instructions (BSF, BCF) and byte-oriented instructions provide compact code density. The device has no on-chip oscillator, requiring an external crystal, ceramic resonator, or RC network on OSC1/OSC2.
Typical applications include automotive body and chassis ECUs (HVAC controls, seat modules, mirror controllers), white goods and appliance control boards (washing machines, dishwashers, microwave ovens), low-cost consumer electronics (remote controls, toys, small appliances), industrial sensor signal conditioning, and battery-powered instrumentation where the small code footprint and low pin count are advantageous. In many legacy designs, the PIC16C554 continues to be specified because of its long-term firmware stability and Microchip's continued availability through the automotive/extended-temperature supply chain.
Design tip: The PIC16C554 has no internal oscillator - the system clock must be supplied externally on OSC1/OSC2. For low-power standby designs, the SLEEP instruction halts the core clock but the WDT can continue running; choose WDT postscaler carefully to balance wake-up latency with current draw. The MCLR reset pin must be pulled high through a resistor for normal operation; a simple RC on MCLR provides a power-on reset delay.
This page consolidates distributor pricing, drop-in 20-SSOP alternatives within the PIC16C5x family, and practical design notes that go beyond the manufacturer datasheet's basic specifications.
Drop-in alternatives for PIC16C554-04E/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 PIC16C554-04E/SS (same form factor and footprint) — differing in Package, Program Memory Type, Program Memory Size, Timers, RAM Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C554-04I/SS
✅ Drop-In✓ In Stock
$1.45 / Unit
View Datasheet →PIC16C554T-04E/SS
✅ 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 →PIC16C54C-04E/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C55-10I/SS
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC16C554-04E/SS Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC 16C |
| Core | PIC 8-bit RISC |
| Instruction Set Width | 14-bit |
| Number of Instructions | 35 (single-word) |
| Program Memory Type | OTP (EPROM-based) |
| Program Memory Size | 896 B (512 x 14) |
| RAM Size | 80 B |
| EEPROM Size | None |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns @ 4 MHz |
| Operating Voltage Range | 3.0 V to 5.5 V |
| I/O Pins | 13 |
| Peripherals | POR, WDT (on-chip RC) |
| Package | 20-SSOP (5.30 mm body, 0.65 mm pitch) |
| Mounting Type | Surface Mount (Gull-wing) |
| Operating Temperature | -40 °C to +125 °C (E grade) |
| Temperature Grade | Automotive / Extended |
| Lead-Free / RoHS | Compliant |
| Timers | 1 x 8-bit (TMRO) |
| ADC | None |
| Communication | None (no UART/SPI/I2C hardware) |
PIC16C554-04E/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 port A bit 4 / 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 input |
| 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 | VDD — Positive supply voltage (3.0 V to 5.5 V) |
| Pin 15 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 16 | OSC2/CLKOUT — Oscillator crystal output / clock output (Fosc/4) |
| Pin 17 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 18 | RA1 — Bidirectional I/O port A bit 1 |
| Pin 19 | NC — Not connected (per datasheet, pin reserved) |
| Pin 20 | NC — Not connected (per datasheet, pin reserved) |
Typical Applications
PIC16C554-04E/SS is suitable for 6 applications: Automotive Body Control Modules, White Goods and Appliance Control, Low-Cost Consumer Electronics, Industrial Sensor Signal Conditioning, Battery-Powered Instrumentation, Legacy System Sustainment / EOL Bridge.
Automotive Body Control Modules
The PIC16C554-04E/SS is well-suited for automotive body and chassis ECUs including HVAC blend-door actuators, seat-position controllers, mirror-fold modules, and window lift switches. Its 896 B OTP program memory is sufficient for the small state machines driving these loads, while the 13 GPIO pins can directly drive relays, LEDs, and H-bridge enable signals through external FETs. The E temperature grade (-40C to +125C) tolerates under-hood and door-mounted thermal stress. Unlike flash-based PIC16F parts, the OTP architecture means firmware is locked at production, eliminating the risk of field reprogramming by unauthorized tools - a benefit for OEM IP protection. Designers typically pair the MCU with a TC4427 gate driver and use TMRO for debounce and PWM generation.
Recommended
White Goods and Appliance Control
In washing machines, dishwashers, and microwave ovens, the PIC16C554-04E/SS functions as the user-interface and motor-control supervisory MCU. Its 35 single-word instructions and 200 ns cycle time deliver deterministic response to keypad events, while the on-chip Watchdog Timer with dedicated RC oscillator recovers the system from motor-induced EMI upsets. The 13 GPIOs scan 4x4 matrix keypads, drive 7-segment or character LCD bias, and toggle triac/relay outputs via zero-cross optocouplers. OTP one-time programmability locks the calibration constants at production line, preventing field tampering. The 20-SSOP package profile sits below the user-accessible enclosure, saving PCB area versus larger DIP variants.
Recommended
Low-Cost Consumer Electronics
Remote controls, electronic toys, and small kitchen appliances leverage the PIC16C554-04E/SS to keep BOM cost below $1 USD while maintaining Microchip's reputation for reliable RISC cores. The 896 B OTP holds sophisticated IR protocols (RC5, NEC, Sony SIRC) or toy sound-effect sequencers with room to spare. The 8-bit TMRO generates precise carrier frequencies (38 kHz, 56 kHz) for IR transmission without CPU overhead. SLEEP mode plus WDT wake-up delivers multi-year battery life in coin-cell toys. The 20-SSOP low-profile footprint allows placement inside ultra-thin remote enclosures. Engineers migrating from PIC16C54 code can reuse most firmware with minor changes due to register-compatible core architecture.
Recommended
Industrial Sensor Signal Conditioning
Factory-floor sensor interfaces use the PIC16C554-04E/SS to linearize thermistor/RTD bridges, multiplex multiple analog inputs through external analog switches, and present calibrated data on UART-emulated bit-banged GPIO. The 4 MHz oscillator and 200 ns instruction cycle allow software-based 10-bit sigma-delta ADC implementations at rates up to 1 kHz when paired with an external op-amp integrator. The wide 3.0-5.5 V supply range tolerates 24V industrial rails after front-end regulation. E temperature grade supports outdoor enclosures and proximity to motors. OTP memory locks factory calibration coefficients, ensuring field units cannot be inadvertently re-tuned.
Recommended
Battery-Powered Instrumentation
Handheld multimeters, portable data loggers, and field-test instruments adopt the PIC16C554-04E/SS for its combination of low cost, deterministic RISC execution, and the SLEEP + WDT wake-up mechanism that delivers multi-year battery life on 2x AA cells. The 13 GPIOs drive LCD segment bias, scan key matrices, and toggle low-side FETs for measurement ranges. With the system clock stopped, the WDT draws only microamps from its internal RC oscillator, allowing duty-cycled wake-measure-transmit operation. OTP storage locks the calibration certificate at manufacture, satisfying NIST-traceable instrumentation requirements.
Recommended
Legacy System Sustainment / EOL Bridge
OEMs with installed bases of products built around the PIC16C554 use this part as a long-term sustainment component to service field returns, warranty repairs, and regulatory re-certifications. Microchip has committed to multi-decade availability of legacy OTP microcontrollers specifically to support automotive and industrial customers whose end-product life cycles exceed 15 years. The E temperature grade, RoHS compliance, and continued factory production (per Microchip's product longevity program) make this part a safe choice for repair stock and newly-built units that must match legacy firmware behavior. Designers should pin-compatible migrate to PIC16C554-04I/SS for benign environments to reduce unit cost.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C554-04E/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C554-04I/SS | PIC16C554T-04E/SS | PIC16C554-04E/SO | PIC16C55-10I/SS | PIC16C54C-04E/SS |
|---|---|---|---|---|---|---|
| Package | 20-SSOP | 20-SSOP - same | 20-SSOP - same | 20-SOIC (wide-body, different footprint) | 20-SSOP - same | 20-SSOP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | |
| Program Memory (OTP) | 896 B (512 x 14) | 896 B | 896 B | 768 B (-14%) | 512 B (-43%) | |
| RAM Size | 80 B | 80 B | 80 B | 25 B | 25 B | |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 10 MHz | 4 MHz | |
| Operating 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 | |
| Temperature Grade | -40C to +125C (E / Automotive) | -40C to +85C (I / Industrial) | -40C to +125C (E) | -40C to +85C (I) | -40C to +125C (E) | |
| I/O Pins | 13 | 13 | 13 | 12 | 12 |
Key Differentiators
- Extended -40C to +125C automotive temperature grade with OTP firmware lock (vs PIC16C554-04I/SS)
- Larger 896 B OTP and 80 B RAM versus PIC16C54C family (vs PIC16C54C-04E/SS)
- Same 20-SSOP pinout as PIC16C55 family but with slower 4 MHz speed grade (vs PIC16C55-10I/SS)
Design Notes
The PIC16C554-04E/SS has no internal oscillator, so the system clock must be supplied externally on OSC1/OSC2. Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of pin 14, plus a 10 µF tantalum or aluminum-polymer bulk capacitor on the same rail. During SLEEP the core stops but the WDT continues running from its internal RC; the typical sleep current is <1 µA at 3 V, allowing multi-year battery life in coin-cell designs.
The 20-SSOP package has a 0.65 mm pitch and 5.30 mm body width per JEDEC MO-150. Route all signals on the outer layers and place a continuous ground pour on the inner layer directly under the IC body for thermal spreading. Keep crystal traces short (under 10 mm) and surround them with a ground guard ring to reduce EMI susceptibility. The MCLR pin (4) requires a 10 kohm pull-up to VDD; adding a 100 nF capacitor to ground on MCLR provides a software-free power-on reset delay.
Three pitfalls trip up first-time PIC16C554 designers: (1) the device is OTP - firmware cannot be erased or re-programmed in-circuit; use a PIC16C554-04I/SS engineering sample or a flash-based PIC16F15344 for development; (2) there is no UART, SPI, or I2C hardware - implement these protocols via bit-banging on GPIO; (3) the Watchdog Timer is enabled by configuration fuse and uses a separate internal RC oscillator (~18 µs nominal period) - postscaler must be configured in software to set the actual WDT timeout. Failing to disable the WDT in low-power designs can drain batteries faster than expected.
When using GPIO pins to bit-bang high-speed protocols (IR carriers at 38 kHz, RC5 at 36 kHz, NEC at 38 kHz), keep the carrier generation tight by aligning the toggle with TMRO overflow interrupts. A 4 MHz oscillator yields 1 µs instruction cycles, so a half-period toggle at 38 kHz (13.2 µs) leaves roughly 6 instructions for housekeeping. Place any RC low-pass filter on GPIO outputs within 5 mm of the pin to suppress ringing; add a 33 ohm series resistor on fast-edge signals to dampen transmission-line effects on the 20-SSOP lead frame.
Compliance Information
RoHS and REACH compliance per Microchip product declaration; lead-free 20-SSOP package. AEC-Q100 automotive qualification status not explicitly listed in provided data - set to unknown. E temperature grade (-40C to +125C) supports automotive operating environments but does not imply AEC-Q100 certification.
