PIC16C54A-04I/SS - 8-bit EPROM MCU, 4MHz, SSOP-20 | Microchip
MPN: PIC16C54A-04I/SS ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.62 | $16.20 |
| 100 | $1.38 | $138.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $1.05 | $1,050.00 |
PIC16C54A-04I/SS Overview
An 8-bit PIC microcontroller (Programmable Intelligent Computer) is a Harvard-architecture RISC processor that executes single-cycle instructions from program memory while accessing a separate data memory space. Within the broader product taxonomy, the PIC16C5X belongs to the PIC16 family of mid-range microcontrollers, which itself sits within Microchip's 8-bit microcontroller portfolio under the Integrated Circuits > Microcontrollers category. EPROM-based PICs like the PIC16C54A were widely used in cost-sensitive, high-volume embedded applications where the program code is finalized at production time.
Key features of the PIC16C54A-04I/SS include 12 I/O pins, an 8-bit real-time clock/counter (TMR0), a two-level hardware stack, and seven or eight special function hardware registers. Direct, indirect, and relative addressing modes are supported for both data and instructions. The 25-byte data RAM is shared with the seven special function registers, leaving a small working register file optimized for compact code. The 12-bit-wide instruction set achieves approximately 2:1 code compression versus competing 8-bit MCUs, an industry-recognized efficiency advantage of the PIC architecture.
The PIC16C54A-04I/SS is built on a fully static CMOS process, allowing the CPU clock to be stopped without losing register state, which is valuable for ultra-low-power standby designs. The '04' speed suffix indicates a 4 MHz maximum oscillator frequency, while the 'A' suffix identifies the enhanced silicon revision over the original PIC16C54. The 'I' grade extends the operating temperature range to industrial -40C to +85C, and '/SS' denotes the SSOP-20 (Shrink Small Outline Package, 208 mil body width) surface-mount form factor.
Typical applications include appliance controllers, simple sensor interfaces, battery chargers, LED drivers, automotive sub-systems (non-safety-critical), and other cost-sensitive embedded products that benefit from a tiny footprint and minimal external component count. With its small memory map and RISC core, the device targets applications where 768 bytes of OTP program storage is sufficient.
When designing with this part, note that Microchip's product page recommends PIC16F54 as the recommended replacement for new designs. The PIC16F54 uses Flash program memory, allowing in-system reprogramming and erasing, which significantly improves development workflow and field-upgrade capability over the OTP PIC16C54A.
Drop-in alternatives for PIC16C54A-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 PIC16C54A-04I/SS (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Timers, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F54-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C54A-04/SS
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC16C54C-04I/SS
✅ Drop-In✓ In Stock
$1.34 / Unit
View Datasheet →PIC16C56A-04I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C54A-04E/SS
✅ Drop-In✓ In Stock
$1.32 / Unit
View Datasheet →PIC16C54A-04I/SS Maximum Ratings & Electrical Characteristics
| Program Memory Type | EPROM (OTP, 512 x 12 words = 768 bytes) |
| Program Memory Size | 768 bytes (512 x 12-bit instructions) |
| Data RAM | 25 bytes |
| CPU Core | 8-bit PIC16C5X RISC |
| Instruction Word Width | 12 bits |
| Maximum Clock Frequency | 4 MHz |
| Supply Voltage (Vdd) | 4.5 V to 5.5 V |
| I/O Pins | 12 |
| Timers | TMR0 (8-bit real-time clock/counter) |
| Hardware Stack | 2 levels |
| Special Function Registers | 7 or 8 (file addressable) |
| Addressing Modes | Direct, Indirect, Relative |
| Operating Temperature Range | -40C to +85C (industrial, 'I' grade) |
| Package | 20-pin SSOP (208 mil, 'SS' suffix) |
| Mounting Type | Surface Mount |
| Process Technology | Fully static CMOS |
| Speed Grade Suffix | 04 (4 MHz max) |
PIC16C54A-04I/SS Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (I/O, bidirectional) |
| Pin 2 | RA3 — Port A bit 3 (I/O, bidirectional) |
| Pin 3 | RA4/T0CKI — Port A bit 4 / TMR0 clock input (open-drain on PIC16C5X) |
| Pin 4 | MCLR — Master Clear (reset) input, active-low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Port B bit 0 (I/O, bidirectional) |
| Pin 7 | RB1 — Port B bit 1 (I/O, bidirectional) |
| Pin 8 | RB2 — Port B bit 2 (I/O, bidirectional) |
| Pin 9 | RB3 — Port B bit 3 (I/O, bidirectional) |
| Pin 10 | RB4 — Port B bit 4 (I/O, bidirectional) |
| Pin 11 | RB5 — Port B bit 5 (I/O, bidirectional) |
| Pin 12 | RB6 — Port B bit 6 (I/O, bidirectional) |
| Pin 13 | RB7 — Port B bit 7 (I/O, bidirectional) |
| Pin 14 | NC — Not connected (no internal bond on SSOP-20 variant) |
| Pin 15 | OSC2 — Oscillator crystal output / CLKOUT |
| Pin 16 | OSC1 — Oscillator crystal input / CLKIN |
| Pin 17 | RA0 — Port A bit 0 (I/O, bidirectional) |
| Pin 18 | RA1 — Port A bit 1 (I/O, bidirectional) |
| Pin 19 | NC — Not connected (no internal bond on SSOP-20 variant) |
| Pin 20 | VDD — Positive supply voltage (4.5V to 5.5V) |
Typical Applications
PIC16C54A-04I/SS is suitable for 6 applications: Appliance Control Boards, Battery Chargers, Automotive Sub-Systems (Non-Safety), LED Lighting Controllers, Simple Sensor Interfaces, Consumer Toy and Hobby Electronics.
Appliance Control Boards
The PIC16C54A-04I/SS's 12 I/O pins and 4 MHz RISC core are well-matched to appliance controllers where the device drives relays, reads keypads, and sequences motors. With 768 bytes of OTP program memory and 25 bytes of RAM, the MCU holds compact state-machine code for washing machines, microwave ovens, and HVAC controls. The industrial -40C to +85C temperature range withstands the thermal stress of motor-control enclosures. The fully static CMOS design allows clock-stopped standby to reduce idle power, important for Energy Star-rated appliances.
Recommended
Battery Chargers
The PIC16C54A-04I/SS is a strong fit for simple NiCd, NiMH, or Li-ion charger controllers where the MCU measures voltage/current, drives indicator LEDs, and implements charge termination logic. Its 4 MHz execution rate provides 1 MIPS, sufficient for monitoring ADC channels via a discrete comparator circuit and timing charge states. The 12 I/O pins handle multiple LED status indicators and a relay/MOSFET control output. Wide supply tolerance (4.5V to 5.5V) tolerates wall-adapter ripple without reseting the core.
Recommended
Automotive Sub-Systems (Non-Safety)
The PIC16C54A-04I/SS industrial temperature range (-40C to +85C) qualifies it for non-safety automotive modules such as interior lighting controllers, seat-position memory, mirror-adjust keypads, and HVAC blend-door actuators. Its small SSOP-20 footprint suits space-constrained dashboards. However, this device is not AEC-Q100 qualified, so safety-critical ECUs should use PIC16F or PIC18 K-line parts. The 8-bit TMR0 counter enables PWM generation for low-frequency motor control.
Recommended
LED Lighting Controllers
For decorative and signage LED controllers, the PIC16C54A-04I/SS drives shift-register LED chains or directly multiplexes small LED matrices. The 12-bit instruction set achieves approximately 2:1 code compression over competing 8-bit MCUs, fitting complex chase patterns within 768 bytes. TMR0 generates PWM dimming for individual color channels. The SSOP-20 package reduces board height in space-constrained architectural fixtures.
Recommended
Simple Sensor Interfaces
The PIC16C54A-04I/SS serves as a low-cost sensor hub that reads discrete sensors, performs threshold detection, and outputs a conditioned signal. Typical applications include temperature threshold alarms, photoelectric beam receivers, and HVAC duct-pressure switches. The hardware stack (two levels) supports simple interrupt-driven subroutines for time-critical sensor polling. The fully static CMOS process permits operation at low clock rates to minimize self-heating and EMI in precision-sensing environments.
Recommended
Consumer Toy and Hobby Electronics
The PIC16C54A-04I/SS's low unit cost and tiny SSOP-20 footprint make it popular in mass-market toys, model-train controllers, and hobbyist kits. Its RISC architecture and 12-bit instructions are simple enough to teach first-time embedded programmers. The 25-byte RAM handles small toy state machines with ease, and 768 bytes of OTP accommodates complete game logic. The industrial temperature range tolerates shipping containers and outdoor use.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54A-04I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F54-I/SS | PIC16C54A-04/SS | PIC16C54C-04I/SS | PIC16C56A-04I/SS | PIC16C54A-04E/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 | 768B OTP EPROM (512 x 12) | 768B Flash | 768B OTP EPROM | 768B OTP EPROM | 1.5KB OTP EPROM (+50%) | 768B OTP EPROM |
| CPU Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Data RAM | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C (industrial) | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +125C (extended) |
| Memory Type | OTP EPROM | Flash (reprogrammable) | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM |
| Lifecycle Status | Obsolete | Active (recommended replacement) | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Identical SSOP-20 pinout and 4 MHz CPU as PIC16C54A but with Flash memory for in-system reprogramming (vs PIC16F54-I/SS)
- Doubled program memory (1.5KB) in same SSOP-20 footprint and pinout (vs PIC16C56A-04I/SS)
- Industrial -40C to +85C temperature grade availability (vs PIC16C54A-04/SS)
Design Notes
The PIC16C54A-04I/SS SSOP-20 footprint requires careful thermal management during hand-soldering: keep the iron below 315C and limit contact time to under 5 seconds per pin to avoid lifting the fine-pitch pads. For production, use a reflow profile with a peak temperature of 235-245C for no more than 30 seconds above 200C, per JEDEC J-STD-020 moisture sensitivity handling guidelines.
Do not assume that the PIC16F54 is a 1:1 register-level drop-in for the PIC16C54A. Although the SSOP-20 pinout and instruction set match, PIC16F54 differences include the configuration-word layout and absence of EPROM calibration cells. Always re-run a full code review when migrating PIC16C5X firmware to PIC16F5X, and verify oscillator startup timing in your specific hardware.
The PIC16C54A-04I/SS draws approximately 1-2 mA active current at 4 MHz and 5V. For battery-powered designs, switch to the lower-power PIC16C54C revision or stop the CPU clock via the watchdog/SLEEP mode to reduce quiescent current to the microamp range. Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of pin 20, and a 10 uF bulk capacitor near the supply entry point.
Because the part uses OTP EPROM, firmware bugs cannot be repaired in-circuit. Always order engineering samples in windowed ceramic packages (e.g., PIC16C54A-04/JW) for prototype development, and only commit the final code to the OTP/SS production units after full validation. Budget for OTP programming fixture cost at low production volumes.
Compliance Information
RoHS/REACH compliance data not present in Verified Web Data; marked as [DATA_NEEDED] in specs. Part is not AEC-Q100 qualified - for safety-critical automotive applications, choose an AEC-Q100 qualified PIC16F or PIC18 K-line successor. Lifecycle status confirmed obsolete per Microchip product page.
