MCP23008T-E/SO Microchip Integrated Circuit (Small Outline Packages) In Stock

Microchip MCP23008T-E/SO is an 8-bit general-purpose I2C I/O port expander with interrupt output, operating from 1.8 V to 5.5 V in an 18-pin SOIC package, enabling microcontrollers to expand their GPIO count over a 2-wire I2C interface.

ACTIVEIntegrated CircuitVerified Jun 2026
Package / Visual Reference
MCP23008T-E/SOSmall Outline Packages
Quick Facts
Manufacturer
Microchip
Package
Small Outline Packages
Pin Count
18
Lifecycle
ACTIVE
Category
Integrated Circuit
Price
From $1.0219(MOQ 2)
RoHS
Compliant
Lead Time
3–7 business days
Shipping
DHL Express · Worldwide

What are the key features of MCP23008T-E/SO?

  • 8-bit bidirectional I/O port expansion over I2C (up to 400 kHz) adds 8 GPIOs to any microcontroller with just 2 signal wires, ideal for GPIO-limited designs
  • Individual pin direction control and programmable internal pull-ups on all 8 I/O pins eliminate external resistors and simplify input interface circuits
  • Interrupt-on-change output notifies the host processor of input state changes without continuous polling, reducing CPU load in event-driven embedded systems

What is MCP23008T-E/SO used for?

The MCP23008T-E/SO is widely used to expand the GPIO count of microcontrollers such as Arduino, ESP32, and STM32 in LED matrix panels, keypad arrays, relay banks, and sensor multiplexers. Its I2C interface and 8-bit parallel I/O make it a standard building block in home automation controllers, industrial HMI panels, and embedded systems that require more digital I/O channels than the host microcontroller's native pins can provide.

What are the specifications of MCP23008T-E/SO?

Pbfree CodeYes
Manufacturer Package CodeSOIC-18
Factory Lead Time6Weeks
YTEOL9
Qualification StatusNot Qualified
uPs/uCs/Peripheral ICs TypePARALLEL IO PORT, GENERAL PURPOSE
PackageSmall Outline Packages

Compliance & Regulatory

RoHS StatusCompliant
Lead-FreeYes (Pb-Free)
ECCNEAR99
HTS Code8542.39.00.01
Country of OriginThailand

Where can I find the MCP23008T-E/SO datasheet?

MCP23008T-E/SO Datasheet Download

Official datasheet from Microchip

What are equivalent replacements for MCP23008T-E/SO?

Compatible alternatives and drop-in replacements for MCP23008T-E/SO:

MCP23009-E/SOMicrochip Technology Inc

Parallel I/O Port, 8-Bit, 8 I/O, CMOS, PDSO18

View Part →

Frequently Asked Questions

How many additional GPIO pins does MCP23008T-E/SO provide and over which interface?

The MCP23008T-E/SO provides 8 additional bidirectional GPIO pins to the host system over a 2-wire I2C bus operating at up to 400 kHz. Each of the 8 pins can be individually configured as input or output via register writes, and all 8 pins can be read or written in a single I2C transaction, minimizing bus communication overhead in fast-scanning applications.

What supply voltage range does MCP23008T-E/SO support, and can it interface directly with 3.3 V microcontrollers?

The MCP23008T-E/SO operates from 1.8 V to 5.5 V supply voltage, making it directly compatible with 3.3 V systems like ESP32, STM32, and Raspberry Pi as well as 5 V Arduino-based platforms. No level shifting is needed when both the I/O expander and the host microcontroller operate at the same supply rail, simplifying the interface circuit to just 2 I2C signal lines.

How does the interrupt-on-change feature of MCP23008T-E/SO reduce CPU load in input-monitoring designs?

The MCP23008T-E/SO asserts its INT output pin whenever any of its 8 input pins changes state, triggering an external interrupt on the host MCU. This eliminates the need for continuous polling at intervals as short as 1 ms, allowing the processor to remain in a sleep or idle state between events. Only when INT fires does the MCU wake and read the INTCAP register to identify which of the 8 inputs changed.

In relay control boards, how does MCP23008T-E/SO compare to using discrete GPIO pins on the microcontroller?

Using MCP23008T-E/SO to drive 8 relay channels over I2C frees up 8 native MCU GPIO pins for other functions, reduces PCB routing complexity (only 2 I2C traces instead of 8 control lines), and allows daisy-chaining of up to 8 MCP23008 devices on a single I2C bus for up to 64 relay channels total. The internal pull-ups on each of the 8 I/O pins also eliminate 8 external resistors per device, saving board area and BOM cost.

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AvailabilityIn Stock
Reference Price (USD)
From $1.0219
Buy from 1pc · Factory-direct pricing
Qty.Unit PriceExt. Price
2+$1.0219$2.04
pcs
Unit price: $1.0219 · Total: $2.04

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Lead Time3-7 business days
MOQFrom 1 piece
ShippingDHL / FedEx / UPS
OriginChina (Authorized)

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