PIC16C54A-04/SS - 8-Bit 4MHz OTP MCU, 768B | Microchip
MPN: PIC16C54A-04/SS ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.1 | $2.10 |
| 10 | $1.85 | $18.50 |
| 100 | $1.55 | $155.00 |
| 500 | $1.32 | $660.00 |
| 1,000 | $1.18 | $1,180.00 |
PIC16C54A-04/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, I/O peripherals, and timers on one die. The PIC16C54A belongs to the original PIC16C5x baseline family introduced by Microchip in the early 1990s; these were the industry's first 8-bit RISC microcontrollers with 12-bit-wide instructions and an 8-bit-wide data path, achieving 2:1 code compression over competing 8-bit architectures in the same price tier. This category sits within the broader hierarchy: 8-bit microcontroller -> RISC microcontroller -> embedded controller -> integrated circuit.
Key features of the PIC16C54A-04/SS include 33 single-word, single-cycle instructions, direct/indirect/relative addressing modes, a power-on reset, a watchdog timer with on-chip RC oscillator, and a wide operating voltage range from 2.5V to 6.0V. The '04' speed grade specifies a 4MHz maximum clock, and the OTP EPROM program memory is ideal for low- to medium-volume production where mask-ROM tooling is uneconomical. CMOS technology delivers low power consumption (typically < 2 mA at 5V/4MHz), making this part suitable for battery-aware applications.
Architecturally, the device uses a Harvard-style separate code and data bus, a 12-bit instruction word, and a small register file of seven or eight special-function hardware registers. This minimal footprint is intentional: the design optimises die area, cost, and predictability for high-volume appliance and consumer-electronics tasks rather than peripheral-rich applications. There is no ADC, no UART, no interrupts, and no on-chip oscillator, keeping the silicon die small and the unit price low.
Typical applications include remote controls, small appliance controls, LED driving patterns, simple sensor interfaces, battery chargers, security keypads, and any cost-sensitive volume-production design that previously used discrete logic. The SSOP-20 footprint is well supported on standard pick-and-place lines and accepts hand-soldering for prototyping.
When designing with this part, note that Microchip's product page explicitly states: a newer device is available, please consider PIC16F54. The PIC16F54 is the recommended flash-memory successor for new designs. The PIC16C54A-04/SS remains in production for existing designs and maintenance spares but should not be selected for new projects.
This page synthesises distributor pricing, cross-reference alternatives, and design notes not found in the manufacturer datasheet alone. Engineers comparing OTP vs flash 8-bit MCUs will find the comparison table and alternatives array particularly useful.
Drop-in alternatives for PIC16C54A-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 PIC16C54A-04/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:
PIC16C54C-04I/SS
✅ Drop-In✓ In Stock
$1.34 / Unit
View Datasheet →PIC16C54A-04I/SS
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC16C54A-04E/SS
✅ Drop-In✓ In Stock
$1.32 / Unit
View Datasheet →PIC16C54A-04T/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F54-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C56A-04/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C54A-04/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit RISC (Harvard, PIC16C5x baseline) |
| Instruction Word Width | 12-bit |
| Data Path Width | 8-bit |
| Instruction Set Size | 33 single-word/single-cycle instructions |
| Maximum Clock Frequency | 4 MHz |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 768 bytes (512 x 12) |
| RAM Size | 25 bytes |
| I/O Pins | 12 |
| Timers | 1 x 8-bit Timer0 with programmable prescaler |
| Hardware Stack Depth | 2 levels |
| Interrupts | None |
| ADC | None |
| Operating Voltage Range | 2.5 V to 6.0 V |
| Operating Temperature Range | -40C to +85C (industrial) |
| Package | 20-pin SSOP (5.30 mm) |
| Mounting Type | Surface Mount |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| Power-On Reset | Yes |
| RoHS Status | Compliant |
PIC16C54A-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 | RTCC — Timer0 clock input (Schmitt trigger) |
| Pin 4 | MCLR/VPP — Master Clear reset (active low) / programming voltage input |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Bidirectional I/O Port B bit 0 |
| 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 | OSC1 — Oscillator input / external clock input |
| Pin 15 | OSC2 — Oscillator output (crystal mode) |
| Pin 16 | VDD — Positive supply voltage |
| 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 20 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C54A-04/SS is suitable for 7 applications: Remote Control Transmitter, Small Appliance Controller, Battery Charger Control, Security Keypad Scanner, LED Chaser / Blinker Patterns, Toy and Game Electronics, Simple Sensor Interface and Signal Conditioning.
Remote Control Transmitter
The PIC16C54A-04/SS is well-suited for infrared remote control transmitters because its 12 I/O pins can drive LED drivers and keypad scan matrices directly, while the 4MHz core executes button-debounce and protocol encoding routines in microseconds. The 768-byte OTP EPROM easily holds fixed IR protocols (RC5, NEC, SIRC). At 3V supply, the CMOS core draws only microamp-level standby current, extending battery life on coin cells for years.
Recommended
Small Appliance Controller
Household appliances such as toasters, blenders, humidifiers, and coffee grinders benefit from the PIC16C54A-04/SS's simple RISC architecture and 12 I/O pins for relay, triac, and indicator LED control. The 768-byte OTP EPROM holds fixed timing routines and the watchdog timer with on-chip RC oscillator protects against firmware lockup during brownout events. Operating from 2.5V-6.0V, the device accepts 3.3V or 5V logic rails common in low-cost appliance designs.
Recommended
Battery Charger Control
The PIC16C54A-04/SS can supervise NiCd, NiMH, or small Li-ion charging cycles through its 8-bit Timer0 with programmable prescaler and direct ADC-less voltage sensing via comparator input pins. The 4MHz core handles -dV detection and timer-based charge termination in firmware. At 2.5V minimum supply, the part can run directly from a discharged battery for diagnostic readout before charging begins.
Recommended
Security Keypad Scanner
Matrix keypads of 3x4 or 4x3 are easily scanned by the PIC16C54A-04/SS using 7 of its 12 I/O pins, with debounce logic running on the 4MHz core. The 768-byte OTP EPROM stores the access code and lockout timing, while the watchdog timer prevents lockup if a vandal shorts the keypad. CMOS low-power operation suits battery-backed alarm panels requiring years of standby life.
Recommended
LED Chaser / Blinker Patterns
Christmas lights, signage indicators, and toy blinker circuits use the PIC16C54A-04/SS to drive 8 to 12 LEDs through direct I/O pins with software PWM for dimming and chaser effects. The 4MHz clock supports smooth PWM frequencies above 100Hz to avoid visible flicker, and the 25-byte RAM holds the running state machine. Low-cost OTP programming is acceptable because patterns are fixed at production.
Recommended
Toy and Game Electronics
Cost-sensitive electronic toys, talking dolls, and simple handheld games leverage the PIC16C54A-04/SS's $1-class unit cost, 4MHz performance, and 12 I/O pins for keypad, sound trigger, and motor control. The OTP memory secures proprietary sound/sequencing patterns from cloning. Watchdog timer and brownout reset keep toys safe during battery insertion and removal by children.
Recommended
Simple Sensor Interface and Signal Conditioning
Industrial sensor front-ends for thermistors, photodiodes, or mechanical switches use the PIC16C54A-04/SS to read inputs through digital I/O with comparator thresholds set by external resistors, then drive alarm relays or 4-20mA loops. The 2.5V-6.0V supply range and -40C to +85C industrial temperature make it rugged for factory floor mounting in junction boxes.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54A-04/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54C-04I/SS | PIC16C54A-04I/SS | PIC16C54A-04E/SS | PIC16F54-I/SS | PIC16C56A-04/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-pin SSOP | 20-pin SSOP - same | 20-pin SSOP - same | 20-pin SSOP - same | 20-pin SSOP - same | 20-pin SSOP - same |
| Program Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | Flash (reprogrammable) | OTP EPROM |
| Program Memory Size | 768 bytes (512 x 12) | 768 bytes (512 x 12) | 768 bytes (512 x 12) | 768 bytes (512 x 12) | 768 bytes (512 x 12) | 1 KB (1024 x 12) |
| RAM Size | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 4 MHz |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| Operating Temperature Range | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +85C (industrial) | 0C to +70C (commercial) |
| Lifecycle Status | NRND | Active (production) | NRND | Active (production) | Active (production) | NRND |
Key Differentiators
- Industrial temperature grade available in same SSOP-20 footprint (vs PIC16C54A-04/SS)
- Flash memory enables in-system reprogramming (vs PIC16F54-I/SS)
- Larger program memory in same SSOP-20 footprint (vs PIC16C56A-04/SS)
Design Notes
The PIC16C54A-04/SS operates from 2.5V to 6.0V; add a 100 nF ceramic decoupling capacitor as close as possible to the VDD pin (pin 16) and a 10 uF bulk capacitor at the board supply input. Power-on reset is internal but MCLR must be tied to VDD through a 10 kohm pull-up for reliable startup. Watchdog timer is enabled in the configuration word - leave it enabled in safety-critical appliance designs to recover from firmware lockup.
Estimated: this device has only a 2-level hardware stack, so recursion and deep subroutines will silently corrupt the return address. Limit call nesting to two levels maximum, or use iterative code patterns. Stack overflow is undetectable and is the most common source of unexplained resets on PIC16C5x designs.
Place the crystal or resonator as close as possible to OSC1 (pin 14) and OSC2 (pin 15), keeping trace lengths under 5 mm. Add a ground guard ring around the oscillator area to reduce EMI pickup. For cost-sensitive designs, the internal RC oscillator option can be selected in the configuration word to eliminate the crystal entirely, at the cost of reduced frequency accuracy.
Estimated: the PIC16C54A I/O pins have limited drive strength (typically 20 mA source/sink); when driving LEDs directly, use a current-limiting resistor sized for 10 mA to stay well within ratings. For higher-current loads, buffer with a MOSFET (e.g., 2N7000) or Darlington (ULN2003). All I/O lines tolerate 5V inputs even when VDD is 3V, simplifying mixed-voltage designs.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified; not recommended for new automotive designs. Refer to PIC16F54 or PIC16F57 for current automotive and industrial programs.
