PIC16C54AT-04I/SS - 8-Bit EPROM MCU, 4MHz, SSOP-20 | Microchip
MPN: PIC16C54AT-04I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.1 | $2.10 |
| 10 | $1.92 | $19.20 |
| 100 | $1.65 | $165.00 |
| 500 | $1.41 | $705.00 |
| 1,000 | $1.21 | $1,210.00 |
PIC16C54AT-04I/SS Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, memory, and peripheral I/O on one die. The PIC16C5X architecture uses a RISC (Reduced Instruction Set Computer) Harvard design with separate program and data buses, which lets the CPU fetch an instruction and read data in the same cycle. PIC16C5X MCUs belong to the broader hierarchy: microcontroller -> embedded controller -> semiconductor device. The 12-bit-wide instruction word delivers a 2:1 code compression ratio over typical 8-bit CISC competitors of the same era, and OTP (One-Time Programmable) EPROM allows firmware customization during prototyping before committing to masked ROM for mass production.
Key features include 33 single-cycle instructions (only program branches are two cycles), 4 MHz maximum clock input, 200 ns instruction cycle, 12 bidirectional I/O pins, an 8-bit timer/counter (TMR0), watchdog timer with on-chip RC oscillator, power-on reset, and brown-out detection. The 12-bit program word and small footprint suit simple control loops where deterministic timing and minimal BOM are critical.
Typical applications include low-cost consumer appliances, sensor signal conditioning, battery chargers, LED controllers, and embedded control logic for white goods and industrial automation. The wide 5 V supply tolerance and industrial temperature range allow deployment in factory-floor equipment and automotive under-hood sub-systems.
When designing with this device, note that OTP memory cannot be re-programmed in-circuit; use the windowed ceramic UV-erasable PIC16C54 variant for development, then move to OTP for production. The 12 I/O pins share peripherals, so plan pin assignments early.
This page combines verified distributor pricing, pin-compatible drop-in alternatives (with same-brand priority), and practical design notes that go beyond the manufacturer datasheet itself.
Drop-in alternatives for PIC16C54AT-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 PIC16C54AT-04I/SS (same form factor and footprint) — differing in Package, Core Architecture, Operating Temperature, Program Memory Size, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C54A-04I/SS
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC16C54A-20I/SS
✅ Drop-In✓ In Stock
$2.51 / Unit
View Datasheet →PIC16C54A-04E/SS
✅ Drop-In✓ In Stock
$1.32 / Unit
View Datasheet →PIC16C54A-04/SS
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC16C54-10I/SS
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →PIC16C54-10/SS
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC16C54AT-04I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Family | PIC16C5X (PIC16C54A revision) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 768 B (512 x 12 words) |
| RAM | 25 B |
| EEPROM | None |
| Data Bus Width | 8 bit |
| Instruction Word Width | 12 bit |
| Max CPU Clock | 4 MHz |
| Instruction Cycle | 200 ns |
| Supply Voltage | 4.5 V to 5.5 V |
| I/O Pins | 12 |
| Timers | 1 x 8-bit (TMR0) |
| Watchdog Timer | Yes (with on-chip RC oscillator) |
| Brown-out Reset | Yes |
| Power-on Reset | Yes |
| ADC | None |
| Operating Temperature | -40 C to +85 C (industrial) |
| Package | SSOP-20 (5.30 mm body width) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC16C54AT-04I/SS Pin Configuration
| Pin 1 | RA0/GP0 — Bidirectional I/O port A bit 0 |
| Pin 2 | RA1/GP1 — Bidirectional I/O port A bit 1 |
| Pin 3 | RA2/GP2 — Bidirectional I/O port A bit 2 |
| Pin 4 | RA3/GP3 — Bidirectional I/O port A bit 3 |
| Pin 5 | RA4/T0CKI — Bidirectional I/O port A bit 4 / Timer0 clock input |
| 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 |
| Pin 15 | VDD — Positive supply 4.5 V to 5.5 V |
| Pin 16 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 17 | OSC1/CLKIN — Oscillator input / external clock in |
| Pin 18 | MCLR/VPP — Master clear reset / programming voltage |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C54AT-04I/SS is suitable for 6 applications: White Goods and Appliance Control, Battery Charger Control, LED Lighting and Signage Controllers, Industrial Sensor Signal Conditioning, Automotive Body and Interior Modules, Remote Control and IR Receiver Nodes.
White Goods and Appliance Control
The PIC16C54AT-04I/SS is well suited to white-goods appliance control boards such as washing machines, dishwashers, and microwave ovens where cost, determinism, and small footprint matter more than peripherals. The device's 33 single-cycle RISC instructions deliver predictable 200 ns execution timing at 4 MHz, ideal for PWM-driven motor control loops and discrete digital I/O sequencing. The 12 GPIO pins drive relays, triac optocouplers, and seven-segment displays directly with no external logic, keeping BOM cost low. Industrial -40 to +85 C temperature rating handles under-cabinet and garage environments; OTP EPROM protects firmware against unauthorized read-back, a key requirement for proprietary appliance algorithms. Power-on reset and brown-out detection eliminate the external supervisor, and the SSOP-20 package allows compact PCB layouts behind the user keypad.
Recommended
Battery Charger Control
The PIC16C54AT-04I/SS is a fit for lead-acid and NiMH battery charger controllers where a simple state machine monitors voltage, current, and temperature without an operating system. The 8-bit TMR0 counter, watchdog timer, and 4.5-5.5 V supply allow direct sensing from a 12 V battery divider and thermocouple amplifier rail. The 25-byte RAM is sufficient for charger state tracking (CC/CV/timer) and the 768-byte OTP holds charge profiles for different chemistries. The SSOP-20 footprint keeps PCB area small enough for inline charger modules. Industrial temperature rating covers automotive under-hood and outdoor PV charge-controller environments, while OTP EPROM prevents firmware theft from competitive teardowns.
Recommended
LED Lighting and Signage Controllers
The PIC16C54AT-04I/SS handles simple LED controllers in architectural lighting, channel letter signs, and decorative displays where fixed chase patterns are stored in EPROM. Its 12 GPIO pins can drive up to 12 discrete LED strings or be multiplexed across 7-segment or dot-matrix displays with no external latch logic; the 200 ns instruction cycle supports smooth chase patterns and dimming via software PWM. The 4 MHz clock is enough for hundreds of PWM steps without flicker. OTP memory locks the lighting sequence, preventing end-user firmware modification. Industrial temperature and 5 V supply allow operation from standard AC-DC adapters behind decorative fixtures.
Recommended
Industrial Sensor Signal Conditioning
The PIC16C54AT-04I/SS is appropriate for industrial sensor transmitters that convert analog inputs to digital outputs over simple protocols. While it has no on-chip ADC, external sigma-delta or SAR ADC front-ends can be polled via GPIO; the deterministic 200 ns instruction cycle lets firmware implement custom linearization, scaling, and HART-like bit-banged protocols. The 12-bit-wide instruction path compresses lookup-table code, fitting complex calibration curves into 768 B of OTP. Watchdog timer and brown-out reset ensure reliable recovery in electrically noisy factory environments, and -40 to +85 C rating covers outdoor and panel-mount installations.
Recommended
Automotive Body and Interior Modules
The PIC16C54AT-04I/SS is suitable for non-safety automotive body controllers such as interior lighting, window switches, seat controllers, and accessory timers where a fixed OTP program is acceptable and cost dominates. The 12 GPIO directly drive MOSFET gates and relay coils; the watchdog timer with on-chip RC oscillator meets automotive transient-recovery expectations; and the SSOP-20 small footprint fits behind dashboard switch panels. Brown-out reset handles crank-voltage dips to 4.5 V reliably. Note that AEC-Q100 qualification is NOT claimed for PIC16C54AT-04I/SS - choose PIC16C54A-20E/SS or PIC16F54 with explicit automotive screening for OEM under-hood deployments.
Recommended
Remote Control and IR Receiver Nodes
The PIC16C54AT-04I/SS fits IR remote-control receivers in consumer A/V, toys, and home automation gateways. Its 8-bit TMR0 can capture IR carrier frequencies with software edge detection, and 33 single-cycle instructions are sufficient to decode RC-5, NEC, or proprietary pulse-position-modulation protocols in real time. The 25-byte RAM holds the latest command and key state, while 768 B of OTP stores protocol tables for multiple device families. The 4 MHz clock supports 38 kHz carrier sampling with adequate margin. Low 5 V supply and SSOP-20 footprint allow compact receiver modules that fit behind equipment bezels.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54AT-04I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54A-04I/SS | PIC16C54A-20I/SS | PIC16C54A-04E/SS | PIC16C54A-04/SS | PIC16C54-10I/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SSOP-20 (5.30 mm body) | SSOP-20 (5.30 mm body) - same | SSOP-20 (5.30 mm body) - same | SSOP-20 (5.30 mm body) - same | SSOP-20 (5.30 mm body) - same | SSOP-20 (5.30 mm body) - same |
| Max Clock Frequency | 4 MHz | 4 MHz | 20 MHz | 4 MHz | 4 MHz | 10 MHz |
| Instruction Cycle | 200 ns | 200 ns | 200 ns | 200 ns | 200 ns | 400 ns |
| Program Memory | 768 B OTP (512 x 12) | 768 B OTP (512 x 12) | 768 B OTP (512 x 12) | 768 B OTP (512 x 12) | 768 B OTP (512 x 12) | 768 B OTP (512 x 12) |
| RAM | 25 B | 25 B | 25 B | 25 B | 25 B | 25 B |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| 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 | 2.5 V to 6.0 V |
| Operating Temperature | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | -40 C to +125 C (extended) | 0 C to +70 C (commercial) | -40 C to +85 C (industrial) |
| Packaging Format | Tape & Reel ('T' suffix) | Tube / Tray | Tube / Tray | Tube / Tray | Tube / Tray | Tube / Tray |
Key Differentiators
- Tape-and-reel packaging optimised for SMT production (vs PIC16C54A-04I/SS)
- Higher 4 MHz industrial temperature margin vs commercial parts (vs PIC16C54A-04/SS)
- Latest A-revision silicon with verified PIC16C5X datasheet electricals (vs PIC16C54-10I/SS)
- Lower 4 MHz clock draws less supply current than 20 MHz grade (vs PIC16C54A-20I/SS)
Design Notes
Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of the VDD pin (pin 15) and a bulk 10 uF tantalum or aluminum polymer capacitor on the same supply rail. The PIC16C54A draws up to ~5 mA at 4 MHz and 5 V; the bulk cap prevents supply droop during GPIO transient switching. Tie MCLR (pin 18) to VDD through a 10 kohm pull-up resistor to ensure proper reset; adding a 100 nF capacitor from MCLR to VSS creates a power-on-reset delay that matches the internal POR timing.
The PIC16C54A does NOT support in-circuit serial programming (ICSP) - OTP EPROM is one-time programmable and requires a high-voltage programmer (VPP ~13 V on MCLR) before solder-mounting the part. Windowed ceramic UV-erasable PIC16C54W parts are required for development iteration. Plan a programming fixture and pre-production verification step for any volume production. According to the Microchip PIC16C5X datasheet programming specification, attempting to program after the OTP bit-cell has been stressed beyond specification causes permanent bit failure.
Route the OSC1/OSC2 crystal traces as short as possible (under 10 mm) and guard them with a ground pour to minimize EMI pickup. For RC oscillator operation, place the resistor and capacitor close to OSC1 to reduce stray capacitance. The SSOP-20 thermal pad is NOT present on this package; rely on the copper pour on RA/RB output pins for any modest heat dissipation, but the part is rated for normal commercial current so thermal management is rarely a concern at 4 MHz.
GPIO pins on the PIC16C54A source and sink up to 25 mA per pin with a total package limit of 100 mA. When driving LEDs or relays directly, ensure that no pin exceeds 25 mA and the sum of all I/O currents stays below the package maximum. For noisier loads, place a 100 ohm series resistor at the GPIO output to dampen transmission-line ringing, especially on ribbon-cable connections. The watchdog timer (WDT) runs from an internal 18 ms nominal RC oscillator; enable WDT in firmware for unattended recovery from firmware lockup.
Compliance Information
RoHS and lead-free status confirmed via Microchip product page and DigiKey listing. AEC-Q100 not claimed - the standard PIC16C54A industrial grade is not automotive-qualified; Microchip recommends PIC16F54-I/SS for automotive new designs. REACH compliance per Microchip product page declaration.
