PIC16C56T-XT/SS - 8-Bit OTP MCU, 4MHz, 1.5KB | Microchip
MPN: PIC16C56T-XT/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.66 | $16.60 |
| 100 | $1.48 | $148.00 |
| 500 | $1.32 | $660.00 |
| 1,000 | $1.18 | $1,180.00 |
PIC16C56T-XT/SS Overview
An OTP (One-Time Programmable) microcontroller is a type of non-volatile programmable logic device in which the program memory can be written exactly once after manufacture. The PIC16C5X architecture belongs to the broader 8-bit MCU family (hypernyms: microcontroller -> MCU -> embedded controller -> semiconductor). The RISC instruction set offers 33 single-word, single-cycle instructions, which simplifies code development and accelerates interrupt latency to a deterministic single instruction cycle. The /SS suffix indicates the SSOP-20 surface-mount package, and the /XT speed grade specifies a 4MHz external oscillator input.
Key features include 12 bidirectional I/O pins, an 8-bit timer/counter, a watchdog timer for code-lockup recovery, power-on reset, and code-protection fuses. The device is fully static, allowing the clock to be stopped without losing register state. Power consumption is low thanks to the CMOS process, with standby currents well under 1mA. The device uses an external RC, XT, HS, or LP oscillator (the XT grade targets a 4MHz crystal or ceramic resonator).
Typical applications include industrial control, consumer electronics, automotive subsystems, sensor signal conditioning, simple motor control, and appliance control. The 12 I/O pins are sufficient to drive LED indicators, read button inputs, scan keypads, and interface to SPI or bit-banged peripherals. The 4MHz CPU clock supports timing-sensitive tasks like IR remote control decoding, PWM-style output toggling, and basic serial communication at 9600 baud.
When designing with the PIC16C56T-XT/SS, remember that OTP memory cannot be re-programmed, so firmware must be fully validated before final programming. Ensure that the crystal/oscillator layout follows the 4MHz XT-grade guidelines to avoid start-up failures. For new designs, consider PIC16F-series flash replacements to enable field firmware updates.
Drop-in alternatives for PIC16C56T-XT/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 PIC16C56T-XT/SS (same form factor and footprint) — differing in Package, Program Memory Type, RAM Size, Supply Voltage Range, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C56T-RCE/SS
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC16C56T-LP/SS
✅ Drop-In✓ In Stock
$1.29 / Unit
View Datasheet →PIC16C56T-HSI/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C56T-10E/SS
✅ Drop-In✓ In Stock
$1.42 / Unit
View Datasheet →PIC16C56-RC/P
✅ Drop-In✓ In Stock
$4.65 / Unit
View Datasheet →PIC16C55-XT/SS
✅ Drop-In✓ In Stock
$2.42 / Unit
View Datasheet →PIC16C56T-XT/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Family | PIC16C5X |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 1.5KB (1K x 12) |
| RAM Size | 25 bytes |
| CPU Speed | 4 MHz (XT oscillator grade) |
| Supply Voltage Range | 3.25 V to 6.25 V |
| Operating Temperature Range | 0 C to +70 C (commercial) |
| I/O Pins | 12 |
| Timers | 1 x 8-bit |
| Watchdog Timer | Yes |
| Power-On Reset | Yes |
| Instruction Set | 33 single-word, single-cycle instructions |
| Package | 20-SSOP (5.30 mm body width) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC16C56T-XT/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 — Real-time clock/counter input |
| Pin 4 | /MCLR — Master clear reset (active low) |
| 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 | VDD — Positive supply voltage |
| Pin 15 | OSC2 — Oscillator crystal output (XT grade) |
| Pin 16 | OSC1 — Oscillator crystal input (XT grade) |
| 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
PIC16C56T-XT/SS is suitable for 6 applications: Industrial Sensor Interface Module, Consumer Appliance Control Board, Automotive Body Electronics Subsystem, IR Remote Control Receiver, Simple LED Display and Signage Controller, Battery-Powered Low-Duty-Cycle Sensor Node.
Industrial Sensor Interface Module
The PIC16C56T-XT/SS fits industrial sensor interface modules where 12 GPIO pins are sufficient to read multiple analog sensors (via external ADC), drive status LEDs, and communicate over UART or bit-banged SPI. Its 4MHz CPU clock at 1 MIPS supports real-time polling of temperature, pressure, or flow sensors at 10 Hz update rates. The 1.5KB OTP holds compact protocol stacks such as Modbus RTU slave or HART-like request handlers. Operating from 3.25V to 6.25V, it accepts a regulated 5V rail common in industrial cabinets. For new designs, consider PIC16F-series flash equivalents to enable field firmware updates.
Recommended
Consumer Appliance Control Board
The PIC16C56T-XT/SS is widely deployed in cost-sensitive consumer appliances such as coffee makers, rice cookers, microwave oven control panels, and washing machine user interfaces. Its 12 I/O pins directly drive 7-segment LED displays, scan 4x4 keypads, and read capacitive or mechanical buttons. The 1.5KB OTP stores simple finite state machines for timed cooking cycles, temperature ramp profiles, and safety interlocks. The 4MHz XT oscillator grade provides accurate timing for buzzer tones and PWM-style heating element control. The SSOP-20 footprint enables compact PCB layouts typical of small countertop appliances.
Recommended
Automotive Body Electronics Subsystem
Although OTP-based, the PIC16C56T-XT/SS appears in non-safety automotive body modules such as window lift controllers, mirror adjusters, and interior lighting controllers where firmware is factory-locked. Its 12 GPIO pins drive H-bridge enable signals, read position switches, and PWM-control LED dimming at 4MHz instruction rate. The 0C to +70C commercial temperature range suits cabin applications, while under-hood deployments require the PIC16C56T-10E/SS extended-temperature variant. The 5V supply aligns with automotive 12V-bus regulators. For safety-critical ADAS or ECU functions, choose a more modern PIC18 or dsPIC with CAN and AEC-Q100 qualification.
Recommended
IR Remote Control Receiver
The PIC16C56T-XT/SS is well-suited as a learning or fixed-code IR remote control receiver, decoding 38 kHz carrier pulses from a TSOP-style photodiode receiver. The 4MHz instruction rate samples the demodulated IR signal at 1 us resolution, sufficient to decode NEC, RC5, and Sony SIRC protocols. The 12 GPIO pins drive status LEDs, drive a small beeper for confirmation tones, and bit-bang UART to a host MCU for learned-code playback. The 1.5KB OTP holds multiple protocol decoders and a small lookup table of device codes. The low CMOS power consumption extends battery life in handheld remotes.
Recommended
Simple LED Display and Signage Controller
The PIC16C56T-XT/SS drives small LED matrix displays, scrolling message signs, and decorative lighting controllers where a 12-output design is sufficient. The 4MHz instruction rate multiplexes up to 8x8 LED matrices at 100 Hz refresh with 1/16 duty-cycle dimming via software PWM. The 1.5KB OTP stores character fonts, scrolling algorithms, and animation sequences for static or pre-programmed patterns. The 5V supply aligns with common LED driver ICs like ULN2003 and TPIC6B595. The SSOP-20 footprint allows compact placement inside illuminated signage enclosures where board area is at a premium.
Recommended
Battery-Powered Low-Duty-Cycle Sensor Node
The PIC16C56T-XT/SS powers low-duty-cycle battery sensor nodes such as door/window contact sensors, leak detectors, and remote utility meters where cost is the primary design constraint. The CMOS process draws sub-mA active current at 4MHz and near-zero current in sleep mode (software-controlled clock stop on the XT oscillator). The 1.5KB OTP holds a simple wake-measure-transmit-sleep state machine with debounce and encryption-light payload formatting. The 3.25V minimum supply accommodates 2x AA alkaline cells down to 3.0V with margin, while 6.25V max supports 9V battery applications. For long-life deployments, migrate to PIC16F or PIC18 flash MCUs.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56T-XT/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C56T-RCE/SS | PIC16C56T-LP/SS | PIC16C56T-HSI/SS | PIC16C56T-10E/SS | PIC16C55-XT/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| 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 |
| Program Memory | 1.5 KB (1K x 12) OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 0.75 KB OTP (-50%) |
| RAM | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| Max CPU Speed | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 10 MHz | 4 MHz |
| Oscillator Grade | XT (4 MHz crystal) | RC (low-cost) | LP (low-power) | HS (high-speed) | XT (10 MHz extended temp) | XT (4 MHz crystal) |
| Operating Temperature | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | -40 C to +125 C (extended) | 0 C to +70 C |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| Unit Price (qty 1000) | 1.18 USD | 1.10 USD | 1.22 USD | 1.30 USD | 1.45 USD | 1.05 USD |
Key Differentiators
- Cost-optimized for high-volume 4 MHz commercial designs (vs PIC16C56T-10E/SS)
- Doubles the code space of the smaller sibling (vs PIC16C55-XT/SS)
- Crystal-grade accuracy for timing-sensitive applications (vs PIC16C56T-RCE/SS)
Design Notes
Estimated: OTP memory on the PIC16C56T-XT/SS can be written exactly once, so any production board with even a single firmware bug becomes scrap. Use a PIC16F-series flash equivalent (e.g., PIC16F54) during development and qualification, then port the validated firmware to the OTP part for cost-down production. This dual-MCU development strategy costs an extra week but saves thousands of dollars in scrapped boards if a bug is found late.
Place the 4MHz XT crystal (or ceramic resonator) within 5mm of the OSC1 and OSC2 pins, with short, symmetric traces. Add a 1M ohm parallel bias resistor across the crystal to ensure reliable startup at low temperatures. Decoupling: a 100nF ceramic capacitor must sit within 3mm of the VDD pin (pin 14) with a direct via to the ground plane. For SSOP-20, allocate a small thermal copper pour under the exposed center pad area to reduce ground bounce during GPIO switching.
Estimated: The PIC16C56T-XT/SS draws approximately 2-5 mA active current at 4MHz with all GPIO outputs unloaded. The CMOS process allows the clock to be stopped (sleep mode) with current dropping to under 10 uA, which is critical for battery-powered sensor applications. Wake-up is via watchdog timer overflow, external interrupt on RB0, or port change interrupt on RB<7:4>. If you need deeper sleep (<1 uA), migrate to a PIC16F or PIC18 with nanoWatt technology.
Compliance Information
RoHS and REACH compliance per Microchip product page. Not AEC-Q100 qualified - the PIC16C56T-XT/SS is commercial-grade; for automotive choose an AEC-Q100 part.