MCP23009-E/SO Microchip Integrated Circuit (Small Outline Packages) In Stock
Microchip MCP23009-E/SO is an 8-bit I2C I/O port expander with 8 GPIO lines, interrupt output, and up to 10 MHz bus speed. Operates over 1.8 V to 5.5 V supply range in an SOIC-18 package. Available with worldwide shipping for embedded GPIO expansion projects.
- Manufacturer
- Microchip
- Package
- Small Outline Packages
- Pin Count
- 18
- Lifecycle
- ACTIVE
- Datasheet
- MCP23009-E/SO Datasheet PDF
- Category
- Integrated Circuit
- Temp Range
- -40.0°C to 125.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 8 independently configurable GPIO lines expandable via I2C bus at up to 10 MHz, allowing a single 2-wire interface to control 8 additional inputs or outputs
- Wide supply voltage range from 1.8 V to 5.5 V with interrupt-on-change output for event-driven microcontroller wake-up without polling
- Compact SOIC-18 package with open-drain interrupt pin and configurable internal pull-up resistors on each of the 8 I/O lines
Applications
The MCP23009-E/SO is used in embedded systems where the host microcontroller lacks sufficient GPIO pins, such as industrial control panels, smart home hubs, and multi-LED or multi-relay driver boards. Its I2C interface allows up to 8 devices to share a single 2-wire bus, expanding the system to 64 additional GPIO lines. The interrupt-on-change output enables efficient wake-from-sleep operation in battery-powered IoT gateways and sensor arrays.
Specifications
| Pbfree Code | Yes |
| Manufacturer Package Code | SOIC-18 |
| Factory Lead Time | 6Weeks |
| 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 | 8 |
| 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 |
| ## MCP23009-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 | 8542.39.00.60 |
| Country of Origin | Thailand |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for MCP23009-E/SO:
suggested
Frequently Asked Questions
How many MCP23009-E/SO devices can share a single I2C bus and what address range do they use?
Up to 8 MCP23009-E/SO devices can coexist on one I2C bus using the 3 hardware address pins (A2, A1, A0), providing addresses 0x20 through 0x27. Each device adds 8 GPIO lines, so a single 2-wire I2C bus can control up to 64 additional inputs or outputs at up to 400 kHz standard or 1.7 MHz fast-mode operation.
Which supply voltages does MCP23009-E/SO support, and how does that affect 3.3 V versus 5 V system designs?
The MCP23009-E/SO operates from 1.8 V to 5.5 V, making it directly compatible with both 3.3 V microcontroller systems and legacy 5 V platforms without level-shifting circuitry. At 3.3 V it interfaces directly to ARM Cortex-M or ESP32 I2C buses, while 5 V operation suits Arduino Uno and PIC18 designs with the same SOIC-18 PCB footprint.
How does MCP23009-E/SO handle button or sensor events without constant I2C polling from the host MCU?
The MCP23009-E/SO includes an interrupt-on-change output pin that asserts low whenever any configured input changes state. The host MCU wakes from sleep via its external interrupt pin, then reads the 8-bit INTCAP register over I2C to identify which of the 8 inputs triggered the event, eliminating the need for continuous polling and reducing average current consumption in battery-powered nodes.
For a relay-driver board needing 8 outputs, what output current per pin does MCP23009-E/SO deliver?
Each GPIO pin of MCP23009-E/SO can source or sink up to 25 mA individually, with a maximum total device current of 125 mA. For driving 5 V relay coils requiring more than 25 mA, a small NPN transistor or ULN2003 Darlington array buffers the 8 outputs while the MCP23009-E/SO provides logic-level control via I2C from the host processor.
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