PIC16C54-XTI/SS - 8-bit OTP MCU, 0.75KB, 12 I/O, SSOP-20 | Microchip
MPN: PIC16C54-XTI/SS β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.34 | $2.34 |
| 10 | $2.1 | $21.00 |
| 100 | $1.8 | $180.00 |
| 500 | $1.55 | $775.00 |
| 1,000 | $1.32 | $1,320.00 |
PIC16C54-XTI/SS Overview
An 8-bit microcontroller (MCU) is a small computer-on-a-chip containing a CPU, memory, and peripherals, designed for embedded control tasks. Within the semiconductor taxonomy, the PIC16C54 belongs to the hierarchy: 8-bit MCU -> microcontroller -> embedded processor -> semiconductor IC. RISC-based MCUs like the PIC16C5X use a small, fixed-length instruction set to deliver predictable, deterministic execution β well-suited to real-time control loops where instruction-cycle timing must be known exactly.
Key features include a RISC architecture with 33 single-word/single-cycle instructions, 12-bit-wide instruction words with 8-bit-wide data path, two-level deep hardware stack, and direct/indirect/relative addressing modes. The device integrates an 8-bit real-time clock/counter (TMR0), a watchdog timer (WDT) for runaway-code recovery, and power-on reset (POR) circuitry. Its fully static CMOS design allows the clock to be stopped without losing register state, enabling low-power standby strategies in battery-powered applications.
The PIC16C5X family is fabricated on an OTP (one-time-programmable) EPROM process, which differentiates it from flash-based PIC16F successors. The 'C' in PIC16C54 indicates the EPROM-based windowed/OTP variant. The -XT speed grade corresponds to a 4 MHz maximum oscillator frequency. Because OTP memory cannot be erased electrically, this part is typically used in mature, high-volume products where code revision is finalized.
Typical applications include appliance control, automotive body modules, industrial sensor interfaces, low-end remote controls, and small consumer devices requiring deterministic loop execution. Its 12 I/O pins, hardware stack, and single-cycle instruction set make it appropriate for simple state-machine and timing-critical control tasks. Pairing the MCU with the PICkit 1 or MPLAB PM3 programmer enables development and pre-production programming.
When designing with this part, allocate sufficient decoupling (100 nF ceramic) close to VDD, and ensure the MCLR pull-up is correctly biased. Because the SSOP-20 has limited thermal mass, confirm that industrial-temperature operation (-40C to +85C) is observed when the device is used in enclosed enclosures. For new designs, consider PIC16F54 flash-based drop-in alternatives that allow in-circuit re-programming.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical SSOP-20 design notes that go beyond the bare manufacturer datasheet, helping engineers evaluate the PIC16C54-XTI/SS for both legacy maintenance and new design reuse.
Drop-in alternatives for PIC16C54-XTI/SS β 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 PIC16C54-XTI/SS (same form factor and footprint) β differing in Core Architecture, Maximum Clock Frequency, Package, Operating Temperature, Data RAM.
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Request AlternativesPIC16C54-XTI/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit RISC |
| Instruction Set | 33 single-word/single-cycle instructions |
| Program Memory | 0.75 KB (512 x 12-bit words, OTP EPROM) |
| Data RAM | 25 bytes |
| I/O Pins | 12 |
| Timers | 1 x 8-bit TMR0 + Watchdog Timer |
| Hardware Stack | 2 levels |
| Speed Grade | XT (4 MHz max oscillator) |
| Maximum Clock Frequency | 4 MHz |
| Supply Voltage | 5.0 V nominal (range per datasheet) |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | SSOP-20 (5.30 mm body, JEDEC MO-150) |
| Mounting Type | Surface Mount |
| Memory Type | OTP EPROM (one-time programmable) |
| MSL Level | 1 (per JEDEC J-STD-020) |
PIC16C54-XTI/SS Pin Configuration
| Pin 1 | RA0 β Bidirectional digital I/O / analog input |
| Pin 2 | RA1 β Bidirectional digital I/O / analog input |
| Pin 3 | RA2 β Bidirectional digital I/O / analog input |
| Pin 4 | RA3 β Bidirectional digital I/O / analog input |
| Pin 5 | GND β Ground reference |
| Pin 6 | RB0 β Bidirectional digital I/O with weak pull-up |
| Pin 7 | RB1 β Bidirectional digital I/O with weak pull-up |
| Pin 8 | RB2 β Bidirectional digital I/O with weak pull-up |
| Pin 9 | RB3 β Bidirectional digital I/O with weak pull-up |
| Pin 10 | RB4 β Bidirectional digital I/O with weak pull-up |
| Pin 11 | RB5 β Bidirectional digital I/O with weak pull-up |
| Pin 12 | RB6 β Bidirectional digital I/O with weak pull-up |
| Pin 13 | RB7 β Bidirectional digital I/O with weak pull-up |
| Pin 14 | VDD β Positive supply voltage |
| Pin 15 | OSC1/CLKIN β Oscillator input / external clock input |
| Pin 16 | OSC2/CLKOUT β Oscillator output / clock output |
| Pin 17 | T0CKI β Timer0 external clock input |
| Pin 18 | RA4 β Bidirectional digital I/O (open-drain option) |
| Pin 19 | NC β Not connected (per datasheet) |
| Pin 20 | /MCLR β Active-low master clear reset input (requires pull-up) |
Typical Applications
PIC16C54-XTI/SS is suitable for 6 applications: Industrial Sensor Interface Module, Appliance Control Board, Remote Control Transmitter, Automotive Body Control Module (Interior), Smart Meter Peripheral Board, LED Lighting Controller.
Industrial Sensor Interface Module
The PIC16C54-XTI/SS suits low-cost industrial sensor conditioning boards where deterministic 1 us instruction timing lets a simple state machine debounce, linearize, and protocol-format transducer signals without an RTOS. With 12 digital I/O, designers can drive LED status indicators, read up to 12 contact or logic-level sensor inputs, and emit a UART bit-banged stream to a host PLC. The industrial -40C to +85C rating permits installation in factory-floor cabinets, and the SSOP-20 occupies only 5.3 mm x 7.2 mm of board area, leaving ample space for the signal-conditioning front end. The on-chip watchdog timer recovers the MCU from electrical noise-induced lockups, a frequent failure mode near motor drives and contactors. Compared with a 32-bit Cortex-M0 part, the PIC16C54-XTI/SS reduces BOM cost by 60-70% for applications that need only basic logic and timing.
Recommended
Appliance Control Board
The PIC16C54-XTI/SS is a long-standing workhorse in white-goods and small-appliance controllers, including coffee makers, toaster ovens, rice cookers, and simple washing-machine user-interface boards. Its 12 I/O pins drive 7-segment LED displays, keypad matrices, relay coils, and triac firing circuits, while the 8-bit TMR0 generates the timing base for PWM heating-element control. The fully static CMOS core lets the MCU halt the oscillator in standby, drawing only microamps and meeting Energy Star idle budgets. The OTP EPROM program memory is appropriate for mature SKUs where firmware has been finalized and the per-unit cost savings versus flash-based parts (typically $0.20-0.40) accumulate across high-volume production runs. The SSOP-20 footprint supports both hand-soldered prototyping and full SMT assembly lines.
Recommended
Remote Control Transmitter
Battery-powered infrared and 433 MHz remote controls benefit from the PIC16C54-XTI/SS deterministic 1 us instruction cycle, which produces accurate bit-banged IR carrier frequencies (36 kHz, 38 kHz, 40 kHz) without crystal drift. The 0.75 KB OTP holds a 32-64 button lookup table and protocol encoder, while the 12 I/O scan up to a 4x4 keypad matrix plus status LEDs. The 25-byte RAM is adequate for transient button-debounce state. Because the core is fully static, the firmware halts the oscillator between key presses, drawing under 1 uA standby β a 3 V coin cell can power the remote for 5-10 years. The SSOP-20 hand-solders into the small PCB of a remote-control housing, and the industrial temperature grade tolerates glove-warmed hand operation.
Recommended
Automotive Body Control Module (Interior)
In interior automotive body modules β dome-light controllers, seat-position memories, mirror-adjust switches, and simple RKE receivers β the PIC16C54-XTI/SS handles button-debounce, relay sequencing, and lamp dimming with predictable timing. Its industrial -40C to +85C temperature range is appropriate for cabin installations, where ambient temperatures remain well within spec. Note: this part is NOT AEC-Q100 qualified, so for under-hood or safety-critical modules, Microchip recommends the PIC16F1xxx family. The PIC16C54-XTI/SS's 8-bit TMR0 generates 100 Hz PWM for interior LED dimming, and the watchdog timer recovers from load-dump-induced code lockups. The SSOP-20 footprint is widely used across automotive Tier 1 harness assemblies, simplifying PCB layout reuse.
Recommended
Smart Meter Peripheral Board
The PIC16C54-XTI/SS serves as a low-cost display and keypad driver for electricity, water, and gas meters, where it scans LCD segments, reads electromechanical pulse counters, and forwards readings to a host processor over UART. The 12 I/O drive 4x4 keypads and 7-segment or custom LCD bias networks; the TMR0 provides 1 ms timing for keypad scan and pulse-counting debounce. The OTP memory prevents end-user firmware tampering, an important regulatory feature for utility meters. The industrial temperature range supports outdoor meter installations. The fully static core lets the meter sleep between user inputs, drawing under 1 uA from a lithium primary cell β a critical feature for 20-year-meter-life targets. The SSOP-20 is compatible with automated optical-inspection assembly lines used in high-volume meter production.
Recommended
LED Lighting Controller
The PIC16C54-XTI/SS controls entry-level LED drivers in decorative lighting, signage, and architectural fixtures, where it executes chase patterns, dimming curves, and color-mixing algorithms in firmware. The TMR0 interrupt generates PWM outputs at 1 kHz-10 kHz, sufficient to drive N-channel MOSFET gates without audible flicker. The 12 I/O accommodate RGB channel control plus DMX-512 or 0-10 V dimming input. The OTP memory locks the firmware against unauthorized modification β important for branded lighting products. The industrial temperature range supports outdoor fixture operation. The SSOP-20 PCB footprint is small enough for in-fixture driver boards, and the part's 1 us instruction cycle easily handles 8-16 channel chase updates at 100 Hz refresh rates. For DMX512-RDM bidirectional lighting, migrate to PIC16F1xxx with UART peripheral support.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C54-XTI/SS β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C54C-XTI/SS | PIC16C54A-20I/SS | PIC16C54AT-20I/SS | PIC16C54A-04E/SS | PIC16C54C-04I/SS | PIC16F54-I/SS |
|---|---|---|---|---|---|---|---|
| Package | SSOP-20 | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 0.75 KB OTP EPROM | 0.75 KB OTP EPROM | 0.75 KB OTP EPROM | 0.75 KB OTP EPROM | 0.75 KB OTP EPROM | 0.75 KB OTP EPROM | 0.5 KB Flash (in-circuit re-programmable) |
| Data RAM | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| Max Oscillator Frequency | 4 MHz (XT grade) | 4 MHz (XT grade) | 20 MHz (HS grade, 200 ns instruction cycle) | 20 MHz (HS grade, 200 ns instruction cycle) | 4 MHz (XT grade, 200 ns instruction cycle) | 4 MHz (XT grade, 200 ns instruction cycle) | 20 MHz (Fosc max) |
| Instruction Cycle Time | 1 us at 4 MHz | 200 ns at 20 MHz (C-silicon faster cycle) | 200 ns at 20 MHz | 200 ns at 20 MHz | 200 ns at 4 MHz | 200 ns at 4 MHz | 200 ns at 20 MHz |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| Program Memory Type | OTP EPROM (one-time programmable) | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | Flash (in-circuit re-programmable) |
Key Differentiators
- Original PIC16C54 silicon baseline (400 ns instruction cycle) (vs PIC16C54C-XTI/SS)
- Wide availability in established industrial designs (vs PIC16F54-I/SS)
- PIC16C5X standard SSOP-20 pinout with industrial temperature rating (vs PIC16C54A-04E/SS)
Design Notes
Estimated: at VDD = 5 V and Fosc = 4 MHz, the PIC16C54-XTI/SS core draws approximately 2 mA active and under 1 uA standby (oscillator stopped). Place a 100 nF X7R ceramic decoupling capacitor within 5 mm of the VDD pin, with a 10 uF bulk capacitor at the board supply input. Because the SSOP-20 power pin is pin 14, route the VDD trace on an inner layer to keep the exposed copper from coupling switching noise into the oscillator. When the device runs in standby with the oscillator halted, ensure the MCLR pull-up remains stable to avoid spurious resets from VDD droop.
The PIC16C54-XTI/SS is OTP (one-time programmable) β every unit shipped with code burned into EPROM is final. There is no in-circuit re-programmability. Design the firmware with thorough bench validation BEFORE committing to OTP, ideally using a flash-based PIC16F54 on the same SSOP-20 footprint for development. A second common pitfall: the CONFIG fuse (oscillator selection, WDT enable, code protection) is one-time-only and cannot be changed after programming. Double-check the CONFIG settings against the production specification before any production run. A third issue: the MCLR pin must NEVER be left floating β a 10 kohm pull-up to VDD is mandatory, otherwise the device may intermittently reset or fail to start.
The SSOP-20 has a 0.65 mm pin pitch, requiring a fine-pitch PCB footprint with NSMD (non-solder-mask-defined) pads for reliable reflow. Per IPC-7351, the SSOP-20 land pattern is approximately 0.40 mm wide x 1.90 mm long with 0.65 mm pitch. Route all signals on inner layers to keep the top layer continuous ground plane under the device body for thermal dissipation. Because the SSOP-20 has no exposed pad, thermal performance is limited β the device is rated for industrial 85C ambient, but junction temperature can approach 90C at full I/O load. Place the device away from board hot spots (linear regulators, power resistors) and provide at least 2 mm clearance to high-temperature components.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified β choose PIC16F1xxx family for automotive. Lead-free SSOP-20 package. Halogen-free status not explicitly stated in available data.
