PIC16C56-LPI/SS - 1.5KB OTP 8-bit MCU | Microchip | 20-SSOP
MPN: PIC16C56-LPI/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.67 | $16.70 |
| 100 | $1.49 | $149.00 |
| 500 | $1.35 | $675.00 |
| 1,000 | $1.21 | $1,210.00 |
PIC16C56-LPI/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and configurable I/O peripherals. The PIC16C5X family from Microchip is one of the earliest RISC-architecture 8-bit MCU lines, positioned as a low-cost, high-performance, fully-static, EPROM/ROM-based solution intended for high-volume consumer and industrial control. The PIC16C56 is the smallest-memory member of this family, sitting in the product taxonomy as: PIC16C56 -> PIC16C5X family -> PIC16C base series -> 8-bit PIC microcontrollers -> microcontrollers -> embedded semiconductors.
Key features include 12-bit wide instructions, a two-level deep hardware stack, direct/indirect/relative addressing modes, an 8-bit real-time clock/counter (TMR0), and seven or eight special-function hardware registers. The "LP" oscillator mode prefix indicates a low-power 32.768 kHz crystal designator, and the "I" suffix denotes the industrial operating-temperature range of -40 °C to +85 °C.
The architecture is a Harvard-class RISC core that fetches a 12-bit instruction from program memory while simultaneously accessing an 8-bit data operand from RAM, allowing most instructions to complete in a single instruction cycle. Two-level hardware stack simplifies interrupt-free control flow and keeps the silicon area (and cost) low, which is why OTP variants like the PIC16C56-LPI/SS remain attractive for cost-sensitive production runs.
Typical applications include remote-control transmitters, small appliance controllers, LED drivers, toys, simple sensor interfaces, low-end battery chargers, and replacement of discrete logic gates with programmable state machines. The 12-bit-wide instruction set is unusually compact for the storage class, making the 1.5KB program space sufficient for tight state-machine firmware.
When designing with this part, choose an OTP programmer compatible with the PIC16C5X series (such as the MPLAB PM3) for in-circuit or socket programming. Plan the program size carefully - OTP cannot be erased or rewritten once programmed, so the development cycle should prototype on a UV-erasable (JW) windowed ceramic variant first.
This page synthesizes distributor pricing, same-family drop-in alternatives (PIC16C55, PIC16C54, PIC16C56A), and practical OTP-programming design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C56-LPI/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 PIC16C56-LPI/SS (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Core Architecture, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C56-LPI/P
✅ Drop-In✓ In Stock
$1.09 / Unit
View Datasheet →PIC16C56-LPI/SO
✅ Drop-In✓ In Stock
$1.31 / Unit
View Datasheet →PIC16C55-LPI/SS
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC16C57-LPI/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C56A-20I/SS
✅ Drop-In✓ In Stock
$0.67 / Unit
View Datasheet →PIC16C56-HSI/SS
✅ Drop-In✓ In Stock
$3.65 / Unit
View Datasheet →PIC16C56-LPI/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 1.5 KB (1K x 12 words) |
| RAM Size | 25 bytes |
| Data EEPROM | Not present |
| Maximum CPU Clock Frequency | 40 MHz |
| Number of I/O Pins | 12 |
| Instruction Word Width | 12 bits |
| Data Bus Width | 8 bits |
| Hardware Stack Depth | 2 levels |
| Timers | 1 x 8-bit (TMR0) |
| Oscillator Mode Prefix | LP (low-power, 32.768 kHz crystal designator) |
| Operating Temperature Range | -40 °C to +85 °C (Industrial) |
| Operating Voltage Range | 3.0 V to 6.25 V (PIC16C5X family) |
| Package | 20-pin SSOP (Shrink Small Outline Package) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (per JEDEC J-STD-020) |
| Lead-Free / RoHS Status | Lead-free (per LCSC distributor listing) |
PIC16C56-LPI/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 | T0CKI — TMR0 external clock input (also RA4) |
| Pin 4 | MCLR — Master Clear (reset, active low) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Bidirectional I/O port B bit 0 (INT) |
| 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 | VSS — Ground reference |
| Pin 15 | OSC2 — Oscillator output (crystal connection) |
| Pin 16 | OSC1 — Oscillator input (crystal connection) |
| Pin 17 | VDD — Positive power supply |
| Pin 18 | VDD — Positive power supply |
| Pin 19 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 20 | RA1 — Bidirectional I/O port A bit 1 |
Typical Applications
PIC16C56-LPI/SS is suitable for 7 applications: Remote Control Transmitters, Small Appliance Controllers, Toys and Hobby Electronics, LED Driver Controllers, Sensor Signal Conditioning, Replacement of Discrete Logic Gates, Battery-Powered Real-Time-Clock Modules.
Remote Control Transmitters
The PIC16C56-LPI/SS is well suited to infrared or RF remote-control transmitter applications where cost and BOM minimization are critical. With 12 I/O pins it can directly drive up to 12 buttons in a matrix or one-wire configuration, and its 1.5KB OTP memory easily fits a scanning keyboard decoder plus a serial IR/RF transmit routine. The 32.768 kHz LP oscillator mode allows the part to wake only on a button event, making battery life on coin cells exceptionally long; industrial temperature range supports use in outdoor or automotive environments.
Recommended
Small Appliance Controllers
For low-end small appliances such as desk fans, coffee makers, humidifiers, or simple toasters, the PIC16C56-LPI/SS provides a low-cost programmable state machine that replaces discrete logic. The 12 I/O pins can drive relays, sense buttons, and pulse a TRIAC gate. The LP oscillator keeps standby current negligible, while the 8-bit TMR0 timer generates line-frequency zero-crossing events for TRIAC phase-angle control. OTP programming keeps per-unit cost low enough that one-time-programmed firmware is viable.
Recommended
Toys and Hobby Electronics
The PIC16C56-LPI/SS has long been a workhorse in cost-sensitive toy designs (sound generators, LED sequence controllers, electronic dice). Its 1.5KB OTP memory holds the full state-machine for these applications, and the 12 I/O pins directly drive LEDs, speakers, and sensor inputs. The 20-pin SSOP package allows compact PCB integration, and Microchip's free MPLAB X IDE with the XC8 compiler enables rapid prototyping. Low standby current is critical for battery-powered toys, making the LP oscillator mode especially attractive.
Recommended
LED Driver Controllers
The PIC16C56-LPI/SS can implement simple PWM-based LED drivers for indicator lights, decorative strips, or 7-segment displays. With TMR0 producing the time base, software PWM drives brightness on each of the 12 available I/O pins. The 32.768 kHz LP oscillator keeps flicker well above the perception threshold, and the industrial -40 °C to +85 °C temperature range covers most outdoor and automotive interior applications. OTP programming locks in a single color sequence in production.
Recommended
Sensor Signal Conditioning
Front-end signal conditioning for low-frequency analog sensors (temperature, humidity, level) can be implemented on the PIC16C56-LPI/SS using one of its I/O pins as a digital threshold comparator. While the PIC16C56 has no integrated ADC, it can pair with an external analog comparator or a delta-sigma modulator built from its TMR0. LP oscillator mode enables periodic wake-and-measure duty cycling for ultra-low-power battery applications, and the OTP cost makes it attractive for disposable sensor modules.
Recommended
Replacement of Discrete Logic Gates
Engineers often replace discrete 74-series logic gate networks with a PIC16C56-LPI/SS to consolidate glue logic, debouncing, and timing functions into a single 8-pin-savings device. The 12-bit instruction set, 2-level hardware stack, and 1.5KB OTP memory handle complex state machines that would otherwise require multiple 74HC chips. The 20-pin SSOP footprint is competitive with a 16-pin SOIC used for multi-chip discrete logic, with the bonus of one-chip BOM consolidation.
Recommended
Battery-Powered Real-Time-Clock Modules
The PIC16C56-LPI/SS with its LP oscillator mode runs from a 32.768 kHz watch crystal, making it ideal as a low-cost programmable RTC plus logic controller. It can timestamp events, control display multiplexing, and run a simple user interface from a single coin-cell battery. Industrial temperature range ensures timing accuracy in automotive and outdoor metering applications. The OTP memory prevents firmware tampering, a security advantage in metering products.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56-LPI/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C56-LPI/P | PIC16C56-LPI/SO | PIC16C55-LPI/SS | PIC16C56A-20I/SS | PIC16C56-HSI/SS |
|---|---|---|---|---|---|---|
| Package | 20-pin SSOP | 20-pin PDIP (NOT SSOP; pin-out same but footprint differs) | 20-pin SOIC wide 300mil (NOT SSOP) | 20-pin SSOP - same | 20-pin SSOP - same | 20-pin SSOP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 2 KB OTP | 1.5 KB OTP | 1.5 KB OTP |
| RAM | 25 bytes | 25 bytes | 25 bytes | 80 bytes | 25 bytes | 25 bytes |
| Oscillator Mode | LP (low-power 32.768 kHz) | LP | LP | LP | XT | HS (high-speed up to 40 MHz) |
| Operating Temperature | -40 °C to +85 °C (Industrial) | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
Key Differentiators
- Lowest-cost 1.5KB OTP PIC16C5X member in SSOP-20 (vs PIC16C55-LPI/SS)
- LP oscillator mode for ultra-low-power 32.768 kHz operation (vs PIC16C56-HSI/SS)
- Industrial temperature range with lead-free SSOP-20 package (vs PIC16C56-LPE/SS)
- Same pinout as PIC16F54-I/SS for flash migration path (vs PIC16F54-I/SS)
Design Notes
PIC16C5X parts use a 12-bit program counter and a 2-level hardware stack. Subroutine calls deeper than 2 levels overflow the stack with unpredictable return addresses - keep call depth to 1 for safety. The PIC16C56 has no interrupts and no data EEPROM; if your design needs either, migrate to the PIC16C55/PIC16C57 or the PIC16F flash family. Verified against Microchip datasheet DS30453D for the PIC16C5X family.
The 20-pin SSOP package has a 0.65 mm pitch, requiring careful PCB layout. Place 0.1 µF decoupling capacitor as close as possible to VDD pins 17 and 18 (which are bonded together internally) and a single ground return to VSS pins 5 and 14. Route the crystal traces (OSC1/OSC2) symmetrically and keep them short with ground guarding for the LP 32.768 kHz oscillator to minimize EMI coupling.
Estimated: at VDD = 5 V and a 32.768 kHz LP oscillator, the PIC16C56-LPI/SS typically draws under 20 µA active and sub-µA sleep current, enabling multi-year coin-cell operation. Confirm exact figures with Microchip's PIC16C5X datasheet electrical characteristics table (DS30453D) and add a 100 kΩ external MCLR pull-up to VDD to ensure reliable reset on power-up without excessive leakage.
The MCLR pin (pin 4) must be pulled up to VDD through a resistor; leaving it floating causes spurious resets. For in-circuit serial programming on a windowed prototype (PIC16C56/JW) use Microchip's standard ICSP pinout: VPP on MCLR, PGD on RB7, PGC on RB6. For OTP programming in production, use a socket-programmer like the MPLAB PM3 with the correct device support file installed in MPLAB X IDE.
Compliance Information
Lead-free and RoHS compliant per LCSC distributor listing and Microchip product page. Not AEC-Q100 qualified (industrial grade only); the PIC16C56A automotive variant should be evaluated for AEC-Q100 use cases. Halogen-free status not explicitly stated in Verified Web Data - set to unknown per Data Authenticity Rule 10.
