MCP23S09-E/SO Microchip Integrated Circuit (Small Outline Packages) In Stock
The MCP23S09-E/SO is an 8-bit SPI I/O expander from Microchip, offering 8 bidirectional I/O lines with a maximum SPI clock of 10 MHz in an 18-pin SOIC package. It extends microcontroller GPIO capacity with configurable interrupts and pull-up resistors. Available worldwide with fast delivery.
- Manufacturer
- Microchip
- Package
- Small Outline Packages
- Pin Count
- 18
- Lifecycle
- ACTIVE
- Datasheet
- MCP23S09-E/SO Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $1.1600(MOQ 1)
- Temp Range
- -40.0°C to 125.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
What are the key features of MCP23S09-E/SO?
- 8-bit SPI I/O expander with up to 10 MHz SPI clock for fast GPIO expansion in microcontroller designs
- 8 fully bidirectional I/O pins with configurable internal pull-up resistors for flexible interface design
- 18-pin SOIC-18 package with interrupt output pin for efficient, event-driven I/O management
What is MCP23S09-E/SO used for?
The MCP23S09-E/SO is used in embedded systems to expand the GPIO count of microcontrollers via a high-speed SPI bus at up to 10 MHz, supporting applications such as keypad matrices, LED arrays, and relay drivers with 8 outputs. It fits industrial control panels, home automation nodes, and IoT sensor hubs where additional digital I/O lines are required beyond the host MCU's native pin count. The configurable interrupt output enables low-latency event detection without continuous SPI polling.
What are the specifications of MCP23S09-E/SO?
| Pbfree Code | Yes |
| Manufacturer Package Code | SOIC-18 |
| Factory Lead Time | 7Weeks |
| YTEOL | 9 |
| Clock Frequency-Max | 10MHz |
| JESD-30 Code | R-PDSO-G18 |
| JESD-609 Code | e3 |
| Number of Bits | 8 |
| Number of I/O Lines | 8 |
| Number of Ports | 1 |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOP18,.4 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Peak Reflow Temperature (Cel) | 260 |
| Qualification Status | Not Qualified |
| Supply Current-Max | 1mA |
| Supply Voltage-Max | 5.5V |
| Supply Voltage-Min | 1.8V |
| Supply Voltage-Nom | 5V |
| Surface Mount | YES |
| Technology | CMOS |
| Temperature Grade | AUTOMOTIVE |
| Terminal Finish | Matte Tin (Sn) |
| Terminal Form | GULL WING |
| Terminal Pitch | 1.27mm |
| Terminal Position | DUAL |
| uPs/uCs/Peripheral ICs Type | PARALLEL IO PORT, GENERAL PURPOSE |
| ## MCP23S09-E/SO Alternates Showing results | Image |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.01 |
| Country of Origin | Thailand |
Where can I find the MCP23S09-E/SO datasheet?
MCP23S09-E/SO Datasheet DownloadOfficial datasheet from Microchip
What are equivalent replacements for MCP23S09-E/SO?
Compatible alternatives and drop-in replacements for MCP23S09-E/SO:
suggested
suggested
suggested
suggested
Frequently Asked Questions
How fast can the SPI interface of the MCP23S09-E/SO run, and how does that affect system throughput?
The MCP23S09-E/SO supports an SPI clock frequency up to 10 MHz, allowing a microcontroller to read or write all 8 I/O pins in a single 16-bit SPI transaction in approximately 1.6 µs, making it fast enough for real-time GPIO expansion in control and sensor interface applications.
For a compact embedded controller with limited GPIO, how many additional digital lines does MCP23S09-E/SO add?
The MCP23S09-E/SO adds 8 bidirectional digital I/O lines through a single SPI bus. Multiple devices can be daisy-chained using chip-select lines, theoretically expanding the GPIO count by 8 pins per device while sharing the same 10 MHz SPI bus and requiring only 4 MCU pins for control.
What package and operating temperature range does MCP23S09-E/SO use?
The MCP23S09-E/SO is housed in an 18-pin SOIC package, which is widely supported by standard PCB footprint libraries. It operates across an extended temperature range of -40°C to 125°C, making it reliable for industrial automation and outdoor IoT gateway deployments exposed to temperature extremes.
When would MCP23S09-E/SO be selected over the MCP23008 I2C variant?
MCP23S09-E/SO is preferred when the host MCU already uses I2C for other peripherals and SPI bandwidth is available for GPIO expansion at up to 10 MHz, or when multiple expanders sharing the same SPI bus need unique chip-select addressing without the 3-bit address limitation of 8 I2C devices. The SPI version also supports faster single-cycle reads than typical 100 kHz or 400 kHz I2C transactions.
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