PIC16C54AT-20I/SS - 8-Bit 20MHz OTP MCU, 20-SSOP | Microchip
MPN: PIC16C54AT-20I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.95 | $1.95 |
| 10 | $1.76 | $17.60 |
| 100 | $1.55 | $155.00 |
| 500 | $1.4 | $700.00 |
| 1,000 | $1.25 | $1,250.00 |
PIC16C54AT-20I/SS Overview
An 8-bit OTP microcontroller is a single-chip computer that integrates a CPU, RAM, ROM/EPROM program memory, and peripherals on one die. Compared with mask-ROM microcontrollers, OTP parts allow small-batch programming during prototyping and pre-production, while keeping unit cost low for low-volume production runs. The PIC16C54 sits at the bottom of the PIC family hierarchy: PIC16C54 -> PIC16C5X -> PIC microcontroller family -> 8-bit MCU -> microcontroller -> semiconductor IC. Its RISC-style instruction set contains only 33 single-word instructions, with single-cycle execution except for program branches.
Key features include a RISC architecture with 33 single-word instructions, 12-bit-wide instructions yielding 2:1 code compression versus competing 8-bit MCUs, 25 bytes of general-purpose RAM, 12 I/O pins with independent direction control, an 8-bit timer/counter with 8-bit programmable prescaler, power-on reset, watchdog timer, and code protection. The device operates from 2.5V to 5.5V and consumes low operating current, making it well suited to battery-powered and space-constrained designs.
The PIC16C54 uses a Harvard architecture with separate program and data buses, allowing instruction fetch and data access to occur in parallel. Its OTP program memory is programmed via Microchip's standard ICSP interface and cannot be erased or rewritten, which differentiates it from flash-based PIC16F parts that share the same pinout. The 12-bit instruction word is asymmetric compared to typical 8-bit CISC controllers, yielding denser code and faster execution per MHz.
Typical applications include low-cost embedded controllers, appliance control, simple sensor interfaces, automotive body electronics sub-modules, security and access peripherals, and remote-control transmitters. Its compact SSOP footprint and industrial temperature range suit space-constrained designs that must operate reliably in harsh environments.
When designing with the PIC16C54AT-20I/SS, choose the OTP variant carefully: OTP is one-time programmable and unsuitable for firmware updates, so any code-change requirement would force a board rework. For designs that may need firmware revision, migrate to a flash-based pin-compatible PIC16F54 or similar part with the same SSOP-20 footprint.
This page synthesizes verified distributor pricing, a curated list of drop-in same-package alternatives, and practical design notes - including a frank explanation of the OTP-vs-Flash trade-off - that are not always visible on a single manufacturer datasheet page.
Drop-in alternatives for PIC16C54AT-20I/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-20I/SS (same form factor and footprint) — differing in Package, Maximum Clock Frequency, Program Memory Size, Program Memory Type, Instruction Cycle Time.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C54AT-20/SS
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →PIC16C54A-20I/SS
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.51 / Unit
View Datasheet →PIC16F54-I/SS
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C54AT-20E/SS
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C54AT-10I/SS
✅ Drop-In✓ In Stock
$2.15 / Unit
View Datasheet →PIC16C54AT-20I/SS Maximum Ratings & Electrical Characteristics
| Series | PIC 16C |
| Core Processor | PIC |
| Core Size | 8-bit |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 768 B (512 x 12) |
| RAM Size | 25 B |
| Number of I/O Pins | 12 |
| Number of Instructions | 33 |
| Timer/Counters | 1 x 8-bit with 8-bit prescaler |
| Supply Voltage Range | 2.5 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Package | 20-SSOP |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (T suffix) |
| Watchdog Timer | Yes |
| Power-On Reset | Yes |
| Code Protection | Yes |
PIC16C54AT-20I/SS Pin Configuration
| Pin 1 | MCLR/VPP — Master clear reset input / programming voltage |
| Pin 2 | OSC1/CLKIN — Oscillator crystal input or external clock input |
| Pin 3 | OSC2/CLKOUT — Oscillator crystal output or clock output |
| Pin 4 | VSS — Ground reference |
| Pin 5 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 6 | RA1 — Bidirectional I/O port A bit 1 |
| Pin 7 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 8 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 9 | RB0 — Bidirectional I/O port B bit 0 |
| Pin 10 | RB1 — Bidirectional I/O port B bit 1 |
| Pin 11 | RB2 — Bidirectional I/O port B bit 2 |
| Pin 12 | RB3 — Bidirectional I/O port B bit 3 |
| Pin 13 | RB4 — Bidirectional I/O port B bit 4 |
| Pin 14 | VSS — Ground reference (alternate bond) |
| Pin 15 | RC0 — Bidirectional I/O port C bit 0 |
| Pin 16 | RC1 — Bidirectional I/O port C bit 1 |
| Pin 17 | RC2 — Bidirectional I/O port C bit 2 |
| Pin 18 | RC3 — Bidirectional I/O port C bit 3 |
| Pin 19 | RC4 — Bidirectional I/O port C bit 4 |
| Pin 20 | VDD — Positive supply voltage |
Typical Applications
PIC16C54AT-20I/SS is suitable for 6 applications: Appliance Control Sub-Modules, Automotive Body Electronics Sub-Modules, Remote Control and RF Key Fobs, Security and Access Control Peripherals, Industrial Sensor Interface Nodes, Simple LED Display Controllers.
Appliance Control Sub-Modules
The PIC16C54AT-20I/SS is well suited to small appliance controllers (coffee makers, microwave keypads, washing-machine sub-boards) where the firmware is locked, the BOM cost is critical, and 12 GPIO plus one 8-bit timer is enough to drive the user interface. With 768 B of OTP program memory and 25 B of RAM, the device comfortably runs typical keypad-scan, LED-multiplex, and relay-control loops at 20 MHz. Compared with an 8-bit CISC part in the same price tier, the PIC16C5X RISC architecture yields roughly 2:1 code compression, letting you fit the same state machine into a smaller OTP cell array. The 20-pin SSOP footprint also allows compact PCB placement next to a mains-isolated low-voltage section.
Recommended
Automotive Body Electronics Sub-Modules
Within automotive body controllers - door lock sub-modules, mirror adjusters, or seat-position memory - the PIC16C54AT-20I/SS is a cost-optimized choice for low-bandwidth tasks. The industrial -40 C to +85 C temperature range covers in-cabin conditions, while 2.5V to 5.5V supply tolerance tolerates cranking transients when paired with a regulated 5V rail. The device's 12 GPIO can drive LEDs and read Hall-effect sensors without external logic, and the 200 ns instruction cycle handles 5 kHz sensor sampling with substantial margin. Designers must avoid under-hood placement (where temperatures exceed 85 C) and must consider migrating to a flash PIC for OEM firmware updates.
Recommended
Remote Control and RF Key Fobs
The PIC16C54AT-20I/SS is a strong fit for single-purpose RF key fobs and IR remote controls where the firmware is fixed for the product life and BOM cost dominates the design. The 12 GPIO can directly scan 4x4 key matrices (up to 16 keys via scanning multiplexing) and drive a low-current transmitter enable line; the 8-bit timer is sufficient for Manchester or PWM encoding. Low power consumption at 20 MHz and 2.5V minimum supply let the device run directly from a coin-cell with a boost regulator. The OTP memory prevents accidental over-the-air code rewriting, which is desirable for security-sensitive fob designs.
Recommended
Security and Access Control Peripherals
The PIC16C54AT-20I/SS serves well in low-cost access-control peripherals such as keypad entry pads, simple alarm sensors, and wired magnetic-contact readers. Its 768 B of OTP holds a small state machine plus keypad debounce code, and the 25 B of RAM accommodates a small event queue. With 12 GPIO it can scan a 3x4 keypad and drive an LED and buzzer directly without external logic. The industrial temperature range ensures operation in unheated vestibules. The code-protection fuse prevents reverse-engineering of the access logic, an important security property for this application class.
Recommended
Industrial Sensor Interface Nodes
In industrial sensor interface boards (4-20 mA loop transmitters, simple RTD readers, optical-sensor digitizers), the PIC16C54AT-20I/SS provides an adequate control brain for fixed-function firmware. The 20 MHz clock and 200 ns instruction cycle let the MCU sample an RTD bridge at 100 Hz with digital filtering, then drive a DAC or PWM output stage from the same GPIO. The wide 2.5V to 5.5V supply tolerates 24V industrial bus rails after regulation. Industrial -40 C to +85 C qualification supports outdoor enclosures in most climates.
Recommended
Simple LED Display Controllers
The PIC16C54AT-20I/SS drives small LED matrix displays, 7-segment indicators, and marquee modules where the brightness pattern is finalized. The 12 GPIO can multiplex up to 8 digit-select lines plus 8 segment lines, or run Charlieplexed LED arrays of up to 16 LEDs. The internal 8-bit timer handles multiplexing refresh without software overhead. OTP memory locks the brightness table and animation pattern at production, eliminating accidental field reprogramming that could dim or flicker the display. The SSOP-20 footprint is small enough for inline display modules.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54AT-20I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54AT-20/SS | PIC16C54A-20I/SS | PIC16F54-I/SS | PIC16C54AT-20E/SS | PIC16C54AT-10I/SS |
|---|---|---|---|---|---|---|
| Package | 20-SSOP | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 768 B OTP | 768 B OTP | 768 B OTP | 1 kB Flash | 768 B OTP | 768 B OTP |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 10 MHz |
| Operating Temperature Range | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| RAM Size | 25 B | 25 B | 25 B | 25 B | 25 B | 25 B |
| Supply Voltage Range | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.0 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| Memory Type | OTP | OTP | OTP | Flash | OTP | OTP |
Key Differentiators
- Industrial temperature range in SSOP-20 (vs PIC16C54AT-20/SS)
- Tape-and-reel packaging for high-volume assembly (vs PIC16C54AT-20/SS)
- OTP for lowest unit cost in fixed-firmware designs (vs PIC16F54-I/SS)
- Single 5V supply with 2.5V minimum operation (vs PIC16F54-I/SS)
Design Notes
OTP memory limitation: the PIC16C54AT-20I/SS uses One-Time Programmable EPROM that cannot be erased or rewritten. Once programmed, any firmware bug requires board rework or part replacement. Estimated cost-of-error: at $1.95 unit price plus PCB rework labor, a single firmware revision on a 1000-unit production run can cost $2000+. Mitigation: prototype on a flash-based PIC16F54-I/SS in the same SSOP-20 footprint, validate firmware thoroughly, then port the final image to PIC16C54AT-20I/SS for production.
Place a 0.1 uF decoupling capacitor as close as possible to the VDD pin (pin 20) and a bulk 10 uF tantalum or ceramic cap on the same supply trace. Keep the MCLR/VPP line (pin 1) short and pull it up to VDD through a 10 kohm resistor to avoid spurious resets. Route the OSC1/OSC2 traces (pins 2 and 3) symmetrically and keep them away from switching nodes. The SSOP-20 thermal pad is not present, so standard SSOP layout rules apply.
The PIC16C54AT-20I/SS in SSOP-20 has fine pitch (0.65 mm) - use a PCB land pattern with solder mask defined (SMD) pads and a 0.4 mm solder mask opening for reliable paste release during reflow. Estimated IPC-7351 land pattern: pad length 1.0 mm, pad width 0.45 mm, pad pitch 0.65 mm. For hand prototyping, use SSOP-to-DIP adapter boards from suppliers like SparkFun or Adafruit to avoid hand-soldering the fine-pitch package.
Estimated: at VDD = 5.0 V, 20 MHz clock, and typical active code, the PIC16C54AT-20I/SS draws approximately 2-3 mA active and 1 uA standby. For battery-powered designs, leverage the SLEEP instruction to enter standby between events. Note that unlike flash-based PIC16F parts, the PIC16C54 does not support low-voltage programming below 4.5 V on VDD; ensure your in-circuit programmer supplies 5 V during programming.
Compliance Information
RoHS/REACH compliance status not stated in the provided verified web data; field set to 'unknown' per data authenticity rule. PIC16C54AT-20I/SS is an industrial-grade part, not AEC-Q100 automotive-qualified.
