PIC16C56A-20E/SO - 8-bit OTP MCU, 1.5KB, 20MHz, SOIC-18 | Microchip
MPN: PIC16C56A-20E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.62 | $1.62 |
| 10 | $1.46 | $14.60 |
| 100 | $1.3 | $130.00 |
| 500 | $1.17 | $585.00 |
| 1,000 | $1.04 | $1,040.00 |
PIC16C56A-20E/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer containing a CPU core, program memory, working RAM, and peripherals such as I/O ports and timers. PIC16C5X devices are OTP (One-Time-Programmable) EPROM-based MCUs designed for cost-sensitive embedded applications. Within the broader semiconductor taxonomy, the PIC16C56A belongs to the hierarchy MCU -> microcontroller -> embedded processor -> semiconductor IC, and uses the classic PIC RISC architecture with 12-bit-wide instructions for approximately 2:1 code density versus typical 8-bit CISC cores.
Key specifications include 1.5 KB of OTP program memory (1K x 12), 25 bytes of RAM, 12 digital I/O pins, two 8-bit timers, an instruction cycle time of 200 ns at 20 MHz, and a wide 3.0 V to 5.5 V operating voltage range. The 'E' suffix designates the extended industrial temperature grade (-40C to +125C). The SOIC-18 surface-mount package simplifies board assembly and reflow soldering versus the original PDIP variants.
Architecturally, the PIC16C56A uses a Harvard-style RISC core with a 2-stage pipeline, 33 single-word/single-cycle instructions, and a hardware stack. It features a watchdog timer, power-on reset, brown-out detection (variant-dependent), and a low-power SLEEP mode. The 12-bit instruction word and 8-bit data path produce compact code density while sustaining deterministic interrupt latency for real-time control.
Typical applications include appliance control, simple sensor interfaces, LED driving logic, low-cost consumer electronics, hobbyist projects, and industrial logic replacement where small, deterministic, OTP-programmed MCUs are appropriate. The SOIC-18 package also supports high-volume SMT production lines.
When designing with this device, note that OTP memory cannot be re-programmed in-circuit - select a Flash-based PIC16F equivalent (e.g., PIC16F54) for development cycles that require firmware revision. Decoupling VDD/VSS with a 100 nF ceramic capacitor adjacent to the IC is essential; place MCLR pull-ups and oscillator components to minimize noise-induced resets.
This page consolidates distributor pricing across LCSC, Mouser and Hotenda, real-time cross-reference alternatives from Microchip's same-family PIC16C5X lineup, and practical design considerations beyond what is summarized in the manufacturer datasheet.
Drop-in alternatives for PIC16C56A-20E/SO — 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 PIC16C56A-20E/SO (same form factor and footprint) — differing in Operating Temperature, Package, Timers, Mounting Type, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C56A-20/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C56A-20E/P
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC16C56AT-20E/SO
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC16C56A-04E/SO
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C56A-04E/P
✅ Drop-In✓ In Stock
$1.21 / Unit
View Datasheet →PIC16F54-I/SO
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C56A-20E/SO Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Series | PIC 16C |
| Core Architecture | PIC RISC (Harvard, 12-bit instruction word) |
| Program Memory Size | 1.5 KB (1K x 12) OTP EPROM |
| RAM Size | 25 bytes |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Operating Supply Voltage | 3.0 V to 5.5 V |
| Number of I/O Pins | 12 |
| Number of Timers | 2 x 8-bit |
| Data Bus Width | 8 bit |
| Package | 18-SOIC (7.50 mm width, 0.295") |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +125C (Extended 'E' grade) |
| RoHS Status | Compliant |
| Peripherals | Watchdog Timer, Power-On Reset, SLEEP mode |
PIC16C56A-20E/SO Pin Configuration
| Pin 1 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 2 | RA1 — Bidirectional I/O port A bit 1 |
| Pin 3 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 4 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 5 | RA4/RTCC — I/O port A bit 4 / RTCC timer input (open-drain) |
| Pin 6 | RB0/INT — I/O port B bit 0 / external interrupt |
| 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 | VDD — Positive supply voltage (3.0-5.5 V) |
| Pin 16 | OSC2 — Oscillator output (crystal/RC) |
| Pin 17 | OSC1 — Oscillator input (crystal/RC/external clock) |
| Pin 18 | MCLR — Master clear (reset, active low) |
Typical Applications
PIC16C56A-20E/SO is suitable for 6 applications: Appliance Control Logic, LED Display and Lighting Drivers, Low-Cost Consumer Electronics, Industrial Sensor Interface, Automotive Interior Modules, Hobby and Educational Projects.
Appliance Control Logic
The PIC16C56A-20E/SO fits appliance control logic (washing machines, microwave ovens, dishwashers) thanks to its extended -40C to +125C temperature range, 12 GPIO for relays and buttons, and OTP EPROM that locks firmware permanently after validation. The 20 MHz clock and 200 ns instruction cycle handle timing-sensitive control loops such as PWM motor drive, debounced keypad polling, and sensor sampling. Designers benefit from Microchip's mature PIC16C5X toolchain and the SOIC-18 package's suitability for high-volume reflow assembly. Total system cost stays low because the integrated watchdog timer, two 8-bit timers, and POR eliminate external supervisor ICs.
Recommended
LED Display and Lighting Drivers
The PIC16C56A-20E/SO drives LED displays and decorative lighting fixtures by bit-banging multiplexed outputs across its 12 GPIO. The 200 ns instruction cycle at 20 MHz allows refresh rates well above the human flicker-fusion threshold (typically 60-100 Hz even for 8-digit 7-segment displays). The 3.0-5.5 V supply matches standard LED driver rails, while the extended temperature range supports outdoor fixtures. Because the firmware is locked into OTP, factory-programmed lighting animations cannot be pirated or field-modified - a security advantage for commercial lighting products.
Recommended
Low-Cost Consumer Electronics
The PIC16C56A-20E/SO suits low-cost consumer electronics such as remote controls, simple toys, kitchen timers, and novelty gadgets where per-unit cost and deterministic behavior dominate design priorities. The 1.5 KB OTP is sufficient for compact state-machine firmware, while the 25 bytes RAM accommodates small look-up tables and stack depth for nested interrupts. Consumer products benefit from the SOIC-18 SMT package for automated assembly and from Microchip's stable long-term silicon supply.
Recommended
Industrial Sensor Interface
The PIC16C56A-20E/SO interfaces industrial sensors (limit switches, Hall sensors, simple thermistor bridges) by polling digital inputs and producing relay or transistor-driver outputs. The 12 GPIO handle 4-8 sensor inputs plus output channels, and the two 8-bit timers enable debounce, time-of-flight, and PWM output for proportional control. The -40C to +125C extended temperature meets IEC industrial environmental requirements. The OTP memory ensures the firmware cannot be field-modified - critical for safety-certified industrial installations.
Recommended
Automotive Interior Modules
The PIC16C56A-20E/SO can be used in non-safety automotive interior modules such as ambient lighting controllers, HVAC mode switches, seat-position memory buttons, and accessory multiplexers. The extended -40C to +125C temperature range covers cabin environments, and the 12 GPIO accommodate multiple switch inputs and PWM LED outputs. Note that safety-critical automotive systems require AEC-Q100 qualification - for those use cases, select PIC16F57 or PIC16F722 with proper automotive-grade screening rather than this industrial-grade part.
Recommended
Hobby and Educational Projects
The PIC16C56A-20E/SO works well for hobbyist and educational projects that need an inexpensive, deterministic 8-bit MCU for learning embedded C, assembly, or basic robotics. The 20 MHz clock allows visible LED blinking rates and motor PWM, while the 12 GPIO suffice for line-follower robots, simple alarm systems, and traffic-light simulators. Educators value the locked OTP firmware - students cannot overwrite a working program, but they can swap chips easily. The SOIC-18 footprint fits standard 18-pin breakout boards and breadboard adapters.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56A-20E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C56A-20/SO | PIC16C56A-20E/P | PIC16C56AT-20E/SO | PIC16C56A-04E/P | PIC16F54-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC (7.50 mm) | 18-SOIC - same | 18-PDIP - through-hole | 18-SOIC - same | 18-PDIP - through-hole | 18-SOIC - same |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 4 MHz (-80%) | 20 MHz |
| Program Memory | 1.5 KB OTP EPROM | 1.5 KB OTP EPROM | 1.5 KB OTP EPROM | 1.5 KB OTP EPROM | 1.5 KB OTP EPROM | 1 KB Flash (re-programmable) |
| RAM Size | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| Operating Temperature | -40C to +125C (Extended) | 0C to +70C (Commercial) | -40C to +125C (Extended) | -40C to +125C (Extended) | -40C to +125C (Extended) | -40C to +85C (Industrial) |
| Memory Type | OTP EPROM (one-time programmable) | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | Flash (re-programmable) |
| Approx. Unit Price (qty 100, USD) | 1.30 | 1.10-1.20 | 1.40-1.55 | 1.30-1.40 | 1.20-1.30 | 1.10-1.30 |
Key Differentiators
- Extended industrial temperature range (-40C to +125C) (vs PIC16C56A-20/SO)
- Modern Flash reprogrammability with same footprint (vs PIC16F54-I/SO)
- Lower-cost OTP for fixed-firmware high-volume builds (vs PIC16C56A-04E/P)
Design Notes
Place a 100 nF ceramic decoupling capacitor as close as possible between VDD (pin 15) and VSS (pin 14) to suppress high-frequency switching noise from the internal oscillator. For multi-rail boards, add a 10 uF bulk tantalum or aluminum capacitor within 25 mm of the supply pin. The PIC16C56A-20E/SO draws approximately 2-5 mA active current at 20 MHz and <1 uA in SLEEP mode; if battery life is critical, gate the supply with a low-leakage load switch.
The 18-SOIC package (0.295" body width, 1.27 mm pitch) is compatible with standard SOIC-18 land patterns. Keep oscillator traces short (<20 mm) and route them away from switching signals to avoid injection of noise into the clock input. The MCLR pin (pin 18) requires a 10-50 kohm pull-up to VDD for reliable operation; do not leave it floating. For high-noise environments, add a 100 nF cap from MCLR to VSS to filter out reset glitches.
The OTP EPROM cannot be re-programmed in-circuit - any firmware bug or update requires a new chip. For development, use a Flash-based PIC16F54 or PIC16F57 in the same 18-SOIC footprint, then migrate to PIC16C56A-20E/SO for production. Do not exceed the maximum clock frequency of 20 MHz; the '04' grade variant operates up to 4 MHz and must not be clocked higher. Note that the RA4/RTCC pin has an open-drain output structure - external pull-up resistor required for high-level driving.
Compliance Information
RoHS and REACH compliant per Microchip product page. The SOIC-18 package is lead-free and halogen-free. Not AEC-Q100 qualified - the part is rated for industrial/commercial use but not automotive safety-critical applications.
