PIC16C54AT-20/SS - 8-Bit 20MHz OTP MCU, 768B | Microchip
MPN: PIC16C54AT-20/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.18 | $21.80 |
| 100 | $1.92 | $192.00 |
| 500 | $1.71 | $855.00 |
| 1,000 | $1.55 | $1,550.00 |
| 3,000 | $1.38 | $4,140.00 |
PIC16C54AT-20/SS Overview
What is a microcontroller? A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and configurable I/O peripherals. Within that hierarchy, the PIC16C54A sits in the OTP/EPROM-based 8-bit RISC family, below flash-based mid-range PIC16 devices and far below 32-bit Cortex-M class parts. OTP memory is programmed once with a device programmer and cannot be electrically erased, which lowers per-unit die cost versus flash and suits high-volume, fixed-code embedded products.
Key features include a fully static CMOS design for low power operation, 12 I/O pins with high-current sink/source capability, an 8-bit real-time clock/counter (RTCC) with 8-bit prescaler, watchdog timer with on-chip RC oscillator for reliable operation, power-on reset, and a commercial temperature grade of 0C to +70C. Power-saving SLEEP mode reduces quiescent current to a few microamps, while internal RC oscillator start-up eliminates external clock components for cost-sensitive designs.
The device uses a Harvard architecture with separate program and data buses, providing deterministic single-cycle instruction execution except for two-cycle branches. The 12-bit instruction width is asymmetric versus typical 8-bit cores, allowing most operations to encode both operand and destination in a single word. CMOS EPROM technology gives the part strong ESD and latch-up immunity, supporting industrial environments even though the marketed grade is commercial.
Typical applications include appliance controls, security and access systems, automotive sub-systems (non-safety), consumer electronics, and low-end remote-control transmitters where minimum BOM and deterministic timing dominate design priorities. The 20-SSOP package enables high-density PCB layouts, and the 20 MHz clock speed provides adequate throughput for simple state-machine and timing tasks.
When designing with the PIC16C54A, keep OTP programming margin in mind: the OTP cell requires a higher VPP than flash, and code changes after deployment are impossible - plan firmware revisions at the prototype stage. For development, use the PIC16C54A JW windowed-ceramic variant or the PIC16F54 flash-based drop-in equivalent for iterative code cycles before committing to the OTP production part.
This page synthesizes distributor pricing, same-family same-package drop-in alternatives, and practical design notes for the PIC16C54AT-20/SS that are not consolidated in any single datasheet - including which exact SSOP-20 reel variants, commercial-grade only, can be placed on the same PCB land pattern.
Drop-in alternatives for PIC16C54AT-20/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-20/SS (same form factor and footprint) — differing in Package, Core Architecture, Program Memory Size, Program Memory Type, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C54A-20I/SS
✅ Drop-In✓ In Stock
$2.51 / Unit
View Datasheet →PIC16C54A-20E/SS
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →PIC16C54A-04/SS
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC16C54A-04E/SS
✅ Drop-In✓ In Stock
$1.32 / Unit
View Datasheet →PIC16F54-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C54AT-20/SO
✅ Drop-In✓ In Stock
$2.15 / Unit
View Datasheet →PIC16C54AT-20/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Family | PIC16C5X (PIC16C54A) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 768 B (512 x 12) |
| RAM | 25 B |
| Maximum Clock Frequency | 20 MHz |
| Instruction Word Width | 12 bits |
| Instruction Set Size | 33 instructions (single word/single cycle) |
| I/O Pins | 12 |
| Timers | 1 x 8-bit RTCC with prescaler |
| Watchdog Timer | Yes (on-chip dedicated RC oscillator) |
| Supply Voltage | 3.0 V to 5.5 V |
| Operating Temperature | 0C to +70C (commercial grade) |
| Package | 20-pin SSOP (5.30 mm body width, 0.65 mm pitch) |
| Mounting Type | Surface Mount |
PIC16C54AT-20/SS Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O pin, PORTA bit 2 |
| Pin 2 | RA3 — Bidirectional I/O pin, PORTA bit 3 |
| Pin 3 | RB0 — Bidirectional I/O pin, PORTB bit 0 / interrupt source |
| Pin 4 | RB1 — Bidirectional I/O pin, PORTB bit 1 |
| Pin 5 | RB2 — Bidirectional I/O pin, PORTB bit 2 |
| Pin 6 | RB3 — Bidirectional I/O pin, PORTB bit 3 |
| Pin 7 | RB4 — Bidirectional I/O pin, PORTB bit 4 |
| Pin 8 | RB5 — Bidirectional I/O pin, PORTB bit 5 |
| Pin 9 | RB6 — Bidirectional I/O pin, PORTB bit 6 |
| Pin 10 | RB7 — Bidirectional I/O pin, PORTB bit 7 |
| Pin 11 | T0CKI — Timer0 external clock input |
| Pin 12 | OSC1 — Oscillator input (XT/HS/LP modes) |
| Pin 13 | OSC2 — Oscillator output |
| Pin 14 | VDD — Positive supply voltage (3.0V to 5.5V) |
| Pin 15 | OSC1 — Oscillator input (RC mode) |
| Pin 16 | MCLR — Master clear reset input (active low) |
| Pin 17 | RA0 — Bidirectional I/O pin, PORTA bit 0 |
| Pin 18 | RA1 — Bidirectional I/O pin, PORTA bit 1 |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (3.0V to 5.5V) |
Typical Applications
PIC16C54AT-20/SS is suitable for 6 applications: Appliance Control Boards, Security and Access Control Systems, Consumer Electronics Remote Controls, Automotive Non-Safety Sub-Systems, Industrial Timer and Counter Modules, Low-End Sensor Signal Conditioners.
Appliance Control Boards
The PIC16C54AT-20/SS is well suited to appliance control boards such as washing-machine timers, microwave-oven keypads, and dishwasher cycle controllers. Its 12 I/O pins can drive 7-segment displays, relays, and mechanical switches directly, while the 20 MHz clock provides enough throughput for state-machine sequencing and timing loops. The OTP memory locks in firmware at production, which is ideal for high-volume appliance designs where code never changes. The 20-SSOP package drops onto compact control boards with 0.65 mm pitch, allowing dense layouts behind control panels. Compared to higher-end PIC16F MCUs, the PIC16C54A cuts BOM cost significantly when firmware revision cycles are not required after deployment.
Recommended
Security and Access Control Systems
In security keypads, RFID access readers, and burglar-alarm control panels, the PIC16C54AT-20/SS provides a low-cost 8-bit controller with deterministic single-cycle instruction execution. Its hardware watchdog timer with on-chip RC oscillator delivers fail-safe recovery from firmware lockups - critical for unattended security products. The 12-bit instruction width gives efficient code density for protocol parsers (Wiegand, magnetic-stripe emulation) within the 768-byte OTP budget. Industrial temperature variant (PIC16C54A-20I/SS) is recommended for outdoor or unheated installations. The OTP memory prevents reverse-engineering of the security code from a programmed device, an extra hardening benefit versus flash-based MCUs.
Recommended
Consumer Electronics Remote Controls
For IR/RF remote controls, the PIC16C54AT-20/SS runs at very low duty cycle and enters SLEEP mode between button presses to extend battery life to multi-year levels. Its 20 MHz clock is more than sufficient for IR carrier generation (typically 36 kHz to 56 kHz) and basic button-matrix scanning. The small SSOP-20 package fits inside handheld plastic enclosures. OTP memory prevents firmware cloning from a captured remote, important for pay-TV and garage-door applications. The 33-instruction RISC set keeps firmware under 512 words even with full keypad debouncing, carrier modulation, and rolling-code protocol support.
Recommended
Automotive Non-Safety Sub-Systems
The PIC16C54AT-20/SS has been used historically in non-safety automotive subsystems such as interior lighting controllers, seat-position memory, and accessory timers. Its CMOS design tolerates the wide 3.0V to 5.5V supply variation typical of automotive 12V rails after regulation. The hardware watchdog timer recovers from EMI-induced lockups on noisy automotive buses. Note that AEC-Q100 automotive qualification is not available on this commercial-grade part; for safety-critical automotive applications, migrate to PIC16F15344 or PIC16F18855 which carry AEC-Q100 Grade 0/1 qualification. The SSOP-20 package withstands standard automotive vibration profiles when properly soldered to a 4-layer PCB.
Recommended
Industrial Timer and Counter Modules
For industrial timer/counter modules - process timers, event counters, and machine-cycle monitors - the PIC16C54AT-20/SS provides adequate processing power with deterministic timing. The on-chip 8-bit RTCC with prescaler counts external events via the T0CKI pin up to 20 MHz in toggle mode, eliminating an external counter IC. The hardware watchdog timer with dedicated RC oscillator keeps operation alive through brownouts on long-running industrial plants. The 12 I/O pins drive LED status indicators, relay outputs, and discrete inputs from limit switches. The 20-SSOP package fits DIN-rail timer enclosures alongside signal-conditioning circuitry.
Recommended
Low-End Sensor Signal Conditioners
Simple sensor signal conditioners - thermistor linearizers, transducer excitation drivers, and discrete threshold detectors - fit comfortably within the PIC16C54AT-20/SS resource budget. Its 25 bytes of RAM handles small moving-average filters, while the 768-byte OTP memory stores lookup tables for linearization. The 20 MHz clock supports 100 kSPS ADC-free oversampling using timer-capture techniques. The 12 I/O pins connect to multiple thermistor channels through a mux or directly drive 4-20 mA loops via PWM plus filter. For modern designs, migrate to PIC16F54 with flash to allow calibration coefficients to be updated in-circuit.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54AT-20/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54A-20I/SS | PIC16C54A-20E/SS | PIC16C54A-04/SS | PIC16C54A-04E/SS | PIC16F54-I/SS |
|---|---|---|---|---|---|---|
| Package | 20-SSOP (5.30 mm) | 20-SSOP (5.30 mm) - same | 20-SSOP (5.30 mm) - same | 20-SSOP (5.30 mm) - same | 20-SSOP (5.30 mm) - same | 20-SSOP (5.30 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 4 MHz | 4 MHz | 20 MHz |
| Program Memory Type | OTP EPROM (768 B) | OTP EPROM (768 B) | OTP EPROM (768 B) | OTP EPROM (768 B) | OTP EPROM (768 B) | Flash (768 B) |
| Operating Temperature | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +125C (extended) | 0C to +70C (commercial) | -40C to +125C (extended) | -40C to +85C (industrial) |
| Reprogrammable | No (OTP) | No (OTP) | No (OTP) | No (OTP) | No (OTP) | Yes (Flash, 100K cycles) |
| Approx. Unit Price @ 100 pcs (USD) | $1.92 | $1.95 | $2.10 | $1.65 | $1.80 | $1.95 |
| Recommended for New Designs | No (legacy OTP) | No (legacy OTP) | No (legacy OTP) | No (legacy OTP) | No (legacy OTP) | Yes (active replacement) |
Key Differentiators
- 20 MHz clock speed in commercial temp range (vs PIC16C54A-04/SS)
- Modern flash-based drop-in available within same family (vs All legacy PIC16C54A OTP variants)
- Lowest unit cost in commercial temp SSOP-20 (vs PIC16C54A-20I/SS)
Design Notes
The PIC16C54AT-20/SS at 20 MHz in SSOP-20 has a typical power dissipation of approximately 10 mW at 5V VDD (estimated: 5V x 2 mA IDD active current). This is well within the SSOP-20 thermal envelope, so no heatsink is required. However, in sealed enclosures above 60C ambient, verify that IDD active current remains within the 1.8 mA to 2.5 mA typical range listed in the PIC16C5X datasheet; at extended temperature the leakage can push IDD above the spec limit.
For SSOP-20 hand-soldered prototypes, use a fine-tip soldering iron (under 1 mm tip diameter) at 315C, and clean flux residue with isopropyl alcohol after soldering to prevent long-term corrosion. The 0.65 mm pitch pads are within range of standard 0.5 mm lead-free solder paste stencil printing for reflow. Always include a 100 nF decoupling capacitor within 5 mm of the VDD pin (pin 14 or 20) and a 10 uF bulk capacitor on the supply rail to suppress the MCU's digital switching transients.
Do not assume the PIC16C54AT-20/SS pinout matches PIC16F54 - verify pin-by-pin because some SSOP variants have minor differences in OSC1/OSC2 placement and MCLR routing. Also note that OTP memory can only be programmed once; if firmware bugs are found after programming, the device must be discarded. Always develop and validate on a PIC16F54-I/SS (flash) or PIC16C54A JW (windowed) before committing to the OTP production part. The 25-byte RAM is shared with the stack; deep call nesting can corrupt variables.
Compliance Information
Compliance status not provided in verified web data; assume standard Microchip commercial-grade compliance. AEC-Q100 not qualified - this is a commercial-grade part. For automotive applications migrate to AEC-Q100 qualified mid-range PIC16F devices.
