PIC16C56-HSI/SS - 8-bit EPROM MCU, 1KB, 12 I/O, SSOP-20 | Microchip
MPN: PIC16C56-HSI/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.157 | $6.16 |
| 10 | $5.85 | $58.50 |
| 100 | $5.25 | $525.00 |
| 500 | $4.62 | $2,310.00 |
| 1,000 | $4.1 | $4,100.00 |
| 3,000 | $3.65 | $10,950.00 |
PIC16C56-HSI/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and peripheral interfaces (timers, interrupts, I/O) onto one die. The PIC16C5X baseline architecture belongs to the RISC (Reduced Instruction Set Computer) microcontroller family, which is the parent class for PIC16F, PIC18, and dsPIC devices. Within that taxonomy, the PIC16C56 sits below PIC16C55 (smaller memory variant) and above PIC16C57 (larger memory variant), all sharing the same 12-bit instruction word and 8-bit data path. This baseline MCU category is widely used in cost-sensitive, deterministic embedded applications such as appliance control, sensor interfaces, and simple timers.
Key specifications of the PIC16C56-HSI/SS include a maximum clock speed of 20 MHz (with instruction cycle time of 200 ns at 20 MHz, derived from a four-clock-per-instruction design), 12-bit wide instructions, an 8-bit wide data path, seven or eight special-function hardware registers, a two-level deep hardware stack, and direct/indirect/relative addressing modes for both data and instructions. The device integrates an 8-bit real-time clock/counter (TMR0), a watchdog timer (WDT), and Power-on Reset (POR). Operating voltage spans 4.5 V to 5.5 V with a 5.0 V nominal supply, and the part is rated for the industrial temperature range of -40 °C to +85 °C.
From a system-architecture perspective, the PIC16C56-HSI/SS uses a Harvard memory architecture with separate program and data buses, enabling simultaneous instruction fetch and data access. Its 12-bit instruction set is highly symmetrical, achieving roughly 2:1 code compression versus competing 8-bit microcontrollers in the same class (per Microchip PIC16C5X family documentation). The HSI oscillator option eliminates the need for an external crystal at lower accuracy, reducing BOM cost and PCB area in cost-driven designs.
Typical applications include low-cost consumer appliance controllers, battery chargers, simple sensor signal conditioning, LED lighting controllers, and replacement of discrete logic in timing and sequencing circuits. The 12 GPIO pins support direct drive of small relays, LEDs, and logic-level peripherals, while the integrated TMR0 and WDT provide deterministic timing and recovery from software lockups.
When designing with this part, note that the EPROM program memory is one-time programmable (OTP); for field firmware updates, choose the PIC16F or PIC16C variants with flash/EPROM that can be reprogrammed, or use a JW windowed package for development. Decoupling: place a 0.1 µF ceramic bypass capacitor as close as possible to the VDD pin to suppress switching noise on the internal logic.
This page synthesizes distributor pricing, drop-in SSOP-20 alternatives from the same PIC16C5X family, and practical design notes that are not aggregated on any single manufacturer or distributor page.
Drop-in alternatives for PIC16C56-HSI/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-HSI/SS (same form factor and footprint) — differing in Core Architecture, Package, Program Memory Size, Program Memory Type, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C56-HS/SS
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC16C56-HSI/P
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC16C56A-20I/SS
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.67 / Unit
View Datasheet →PIC16C56AT-20/SS
✅ Drop-In✓ In Stock
$0.85 / Unit
View Datasheet →PIC16F15344T-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C55-HSI/SS
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.4 / Unit
View Datasheet →PIC16C56-HSI/SS Maximum Ratings & Electrical Characteristics
| Product Family | PIC16C5X |
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Instruction Word Size | 12 bits |
| Data Path Width | 8 bits |
| Program Memory Type | EPROM (OTP) |
| Program Memory Size | 1.5 KB (1024 words) |
| Data RAM | 25 bytes |
| Number of I/O Pins | 12 |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns at 20 MHz (4 clocks/instruction) |
| Oscillator Option (HSI) | High-speed internal oscillator |
| Hardware Stack Depth | 2 levels |
| Timers | 8-bit TMR0 |
| Watchdog Timer (WDT) | Yes |
| Power-on Reset (POR) | Yes |
| Supply Voltage (VDD) | 4.5 V to 5.5 V (5.0 V nominal) |
| Operating Temperature | -40 °C to +85 °C (Industrial) |
| Package | SSOP-20 (5.30 mm body, 0.65 mm pitch) |
| Mounting Type | Surface Mount |
| Terminal Form | Gull Wing |
| RoHS Status | Compliant |
PIC16C56-HSI/SS Pin Configuration
| Pin 1 | /MCLR — Master Clear (reset), active-low input |
| Pin 2 | GP0 — Bidirectional I/O port bit 0 |
| Pin 3 | GP1 — Bidirectional I/O port bit 1 |
| Pin 4 | GP2/T0CKI — Bidirectional I/O port bit 2 / Timer0 clock input |
| Pin 5 | GP3 — Bidirectional I/O port bit 3 |
| Pin 6 | GP4 — Bidirectional I/O port bit 4 |
| Pin 7 | GP5 — Bidirectional I/O port bit 5 |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1 — Oscillator input or GPIO (HSI mode) |
| Pin 10 | OSC2 — Oscillator output or GPIO (HSI mode) |
| Pin 11 | GP6 — Bidirectional I/O port bit 6 |
| Pin 12 | GP7 — Bidirectional I/O port bit 7 |
| Pin 13 | GP8 — Bidirectional I/O port bit 8 |
| Pin 14 | GP9 — Bidirectional I/O port bit 9 |
| Pin 15 | GP10 — Bidirectional I/O port bit 10 |
| Pin 16 | GP11 — Bidirectional I/O port bit 11 |
| Pin 17 | NC — Not connected (per datasheet) |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (4.5 V to 5.5 V) |
Typical Applications
PIC16C56-HSI/SS is suitable for 6 applications: Low-Cost Consumer Appliance Control, Battery Charger Controllers (Lead-Acid / NiMH), LED Lighting and Signage Controllers, Sensor Signal Conditioning Front-Ends, Replacement of Discrete Logic Timers, Automotive Interior Accessory Controllers (Non-Safety).
Low-Cost Consumer Appliance Control
The PIC16C56-HSI/SS's 1 KB EPROM, 12 GPIO pins, and 20 MHz core provide enough headroom for state-machine control of small household appliances such as coffee makers, fans, and toasters. The HSI internal oscillator eliminates the external crystal, reducing BOM cost by ~$0.20 per unit in high-volume production. With 25 bytes of RAM, the MCU can hold sensor debounce state, button flags, and timing variables for simple closed-loop control loops without external memory. The integrated watchdog timer recovers the appliance from software lockups caused by EMI, a common reliability requirement for white goods. Operating across 4.5 V to 5.5 V from a rectified mains supply or 5 V regulator, the PIC16C56-HSI/SS is rated for the full industrial temperature range (-40 °C to +85 °C), meeting appliance safety and reliability standards.
Recommended
Battery Charger Controllers (Lead-Acid / NiMH)
The PIC16C56-HSI/SS's TMR0 8-bit timer and 12 GPIO pins can implement constant-current/constant-voltage (CCCV) charge algorithms for sealed lead-acid and NiMH battery packs up to 12 V nominal. By driving a MOSFET gate via PWM through software loops timed by TMR0, the MCU regulates charge current with reasonable accuracy without needing an analog PWM peripheral. The 1 KB EPROM holds the state machine for charge phase transitions (bulk, absorption, float), while the 25 bytes of RAM track voltage setpoints and timer counters. The HSI internal oscillator maintains timing accuracy within ±2% across the industrial temperature range, sufficient for charger timing budgets. With the watchdog timer enabled, the PIC16C56-HSI/SS recovers automatically from brownout-induced software faults on the DC bus.
Recommended
LED Lighting and Signage Controllers
The PIC16C56-HSI/SS can drive multi-channel LED signs, decorative lighting, and indicator panels by sequencing GPIO outputs through software-driven PWM, achieving 8-bit brightness control with 256 dimming levels per channel. The 20 MHz instruction rate supports refresh frequencies above 100 Hz for up to 12 channels simultaneously, eliminating visible flicker in human-perception studies. The HSI internal oscillator removes external crystal cost, and 25 bytes of RAM is sufficient to store color palettes or chase-pattern state for animations. Industrial temperature rating (-40 °C to +85 °C) ensures operation in outdoor LED signage cabinets from cold-winter nights to high-summer heat. The integrated POR ensures clean startup sequencing of the LED drivers, avoiding the inrush current spikes that would otherwise shorten LED lifetime.
Recommended
Sensor Signal Conditioning Front-Ends
The PIC16C56-HSI/SS can serve as a low-cost front-end MCU for simple sensor signal conditioning in thermostats, humidity monitors, and HVAC zone controllers. With 12 GPIO pins, the device reads multiple analog sensors through an external ADC and drives relays or TRIAC outputs, while the HSI internal oscillator maintains stable timing for the ADC sampling loop without external components. The 1 KB EPROM holds linearization lookup tables for thermistor or RTD sensors, and 25 bytes of RAM holds recent sample history for averaging filters. The watchdog timer protects against EMI-induced firmware lockups in industrial environments where motor drives and switching power supplies generate significant noise. Operating from a 5 V regulated supply, the PIC16C56-HSI/SS integrates cleanly with 5 V sensor signal chains.
Recommended
Replacement of Discrete Logic Timers
The PIC16C56-HSI/SS can replace legacy 555-timer or discrete CMOS logic-based timing and sequencing circuits with a single IC, reducing board area by 60-80% in retrofit designs. The 20 MHz core can implement multiple software timers concurrently using TMR0 and software counters, replacing chains of 555 monostable or astable circuits. The 1 KB EPROM holds complex sequencing programs (e.g., washing machine cycles, dishwasher programs) that would be impractical to implement in discrete logic. With the HSI internal oscillator option, no external timing capacitor or resistor is needed, further reducing the BOM count and improving long-term timing stability over electrolytic-cap-based 555 designs. The industrial temperature rating ensures timing accuracy is maintained across operating environments.
Recommended
Automotive Interior Accessory Controllers (Non-Safety)
The PIC16C56-HSI/SS can manage non-safety automotive interior accessories such as ambient lighting controllers, seat-heater timing modules, and accessory delay-off circuits, where its 12 GPIO pins drive MOSFET gates or relay coils directly. The HSI internal oscillator eliminates the external crystal for cost-sensitive automotive aftermarket products, while the industrial temperature rating covers cabin temperatures. The 1 KB EPROM holds the accessory timing state machine (e.g., 30-minute seat-heater auto-off, courtesy light fade-out timing) with margin for future feature additions. Note that for safety-critical automotive applications (airbag controllers, ABS modules), the PIC16C56-HSI/SS is NOT suitable; choose AEC-Q100-qualified parts like PIC16F15344T-I/SS instead. For body and chassis non-safety modules, the PIC16C56-HSI/SS provides a cost-effective 8-bit solution.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56-HSI/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C56-HS/SS | PIC16C56-HSI/P | PIC16C56A-20I/SS | PIC16C56AT-20/SS | PIC16F15344T-I/SS | PIC16C55-HSI/SS |
|---|---|---|---|---|---|---|---|
| Package | SSOP-20 | SSOP-20 | PDIP-20 | SSOP-20 | SSOP-20 | SSOP-20 | SSOP-20 |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1 KB EPROM | 1 KB EPROM | 1 KB EPROM | 1 KB EPROM | 1 KB EPROM | 7 KB Flash | 512 words EPROM |
| RAM | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 512 bytes | 24 bytes |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 32 MHz | 20 MHz |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 18 | 12 |
| Oscillator | Internal HSI | External HS | Internal HSI | Internal HSI | Internal HSI | Internal 32 MHz HFINTOSC | Internal HSI |
| Operating Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 2.3 V to 5.5 V | 4.5 V to 5.5 V |
| Memory Type | EPROM (OTP) | EPROM (OTP) | EPROM (OTP) | EPROM (OTP) | EPROM (OTP) | Flash (reprogrammable) | EPROM (OTP) |
Key Differentiators
- Internal HSI oscillator eliminates external crystal, reducing BOM cost and PCB area (vs PIC16C56-HS/SS)
- SSOP-20 surface-mount package for high-density SMT designs (vs PIC16C56-HSI/P)
- Modern flash upgrade path with vastly more memory and peripherals (vs PIC16F15344T-I/SS)
Design Notes
Place a 0.1 µF ceramic decoupling capacitor as close as physically possible to the VDD pin (pin 20) of the PIC16C56-HSI/SS, with the ground return via a short trace to pin 19 (VSS). For designs driving high-current loads (relays, LEDs) on GPIO pins, add a bulk 10 µF tantalum or aluminum electrolytic capacitor near the VDD pin to suppress voltage dips during load transients. The HSI internal oscillator eliminates the need for external crystal load capacitors, but the OSC1/OSC2 pins should still be left unconnected or routed as no-connect traces to maintain a clean PCB layout. Keep GPIO traces away from relay coil drive traces to avoid EMI coupling into the MCU substrate.
The PIC16C56-HSI/SS uses one-time-programmable (OTP) EPROM, meaning firmware errors after programming cannot be fixed in-circuit; an entire board must be replaced. Always qualify firmware on a JW (windowed) package or PIC16F equivalent before committing to OTP production. The /MCLR pin (pin 1) must be pulled high through a 10 kΩ resistor for normal operation; leaving it floating causes intermittent resets. The HSI internal oscillator accuracy is approximately ±2% over voltage and temperature, which is insufficient for UART baud-rate generation above 9600 baud; use the HS (external crystal) variant for UART applications. The hardware stack is only 2 levels deep, so deeply nested subroutine calls will silently corrupt the return address and cause firmware lockups; keep call depth to 1.
The PIC16C56-HSI/SS typically draws 1.8 mA active at 5 V and 20 MHz, and 4 µA standby current with the watchdog timer disabled, per the PIC16C5X datasheet (DS30453D). For battery-powered applications, enable the watchdog timer periodically rather than running continuously to minimize average current; the WDT adds approximately 4-13 µA depending on oscillator stability. The internal POR circuit holds the MCU in reset until VDD reaches approximately 1.5-2.0 V, preventing undefined execution during power-up brownout. For applications requiring defined brownout behavior below 4.5 V, add an external voltage supervisor IC rather than relying on the internal BOR threshold (which is not present on all PIC16C56 silicon revisions).
Compliance Information
RoHS compliant per Microchip product page; not AEC-Q100 qualified (industrial temp grade only); choose PIC16F15344T-I/SS Q1 variants for automotive. Lead-free terminations per Microchip packaging specifications. Halogen-free status not specified in available data.
