Microchip Technology MCP23008-E/ML

Overview

MCP23008-E/ML from Microchip Technology is an 8-bit I²C-compatible GPIO expander IC designed to extend parallel digital I/O capability in space-constrained embedded systems. It features 8 bidirectional I/O pins (GP0–GP7), hardware address pins A2–A0 for up to eight devices on one bus, configurable interrupt output (INT), and operates from 1.8V to 5.5V across –40°C to +85°C. It serves as a remote port controller in microcontroller-based industrial control panels.

For engineers reviewing the MCP23008-E/ML datasheet, MCP23008-E/ML pinout, MCP23008-E/ML application, or MCP23008-E/ML equivalent, this page delivers verified electrical specs, validated I²C timing (100 kHz / 400 kHz / 1.7 MHz), confirmed package mapping (20-pin QFN), and two rigorously cross-referenced alternative parts with documented functional differences.

Technical Context

The MCP23008-E/ML implements an I²C slave interface with 7-bit addressing (base 0x20–0x27 via A2:A0), supporting sequential and byte-mode register access. Its internal register map includes IODIR, IPOL, GPINTEN, DEFVAL, INTCON, IOCON, GPPU, INTF, INTCAP, GPIO, and OLAT - enabling full software control of direction, polarity, interrupt conditions, pull-up enable, and output latching.

Interrupt logic supports two mutually exclusive modes: interrupt-on-change from previous state or from DEFVAL register comparison. The INT pin is configurable as active-high, active-low, or open-drain via IOCON bits ODR and INTPOL. Power-on reset initializes all registers to POR values, including IODIR = 0xFF (all inputs default).

Key Specifications

Pinout & Package

The MCP23008-E/ML is packaged in a 20-pin QFN (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin 1 is marked by a dot; pin numbering follows standard QFN convention (counterclockwise from top-left corner).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar GPIO expander applications.

Compared with PCA9554APW,118 and TCA6408APWR, the MCP23008-E/ML offers superior interrupt flexibility (dual-source logic + INTCAP), higher I²C speed headroom (1.7 MHz), and greater bus scalability (8 addresses vs. 4 or 1), making it optimal for multi-node, event-driven embedded systems where deterministic response and layout efficiency are critical.

Availability

MCP23008-E/ML is available at Aetrix Electronics and suitable for industrial HMI interfaces, smart sensor node expansion, IoT gateway peripheral control, and automotive body controller subsystems requiring stable component supply and long-term manufacturability.

Supply support for MCP23008-E/ML includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a leading provider of microcontrollers, analog components, and connectivity solutions, serving industrial, automotive, and consumer markets with high-reliability silicon and development tools.

The MCP23X08 product line delivers scalable, low-power I/O expansion for resource-constrained microcontroller systems - emphasizing interrupt efficiency, voltage flexibility, and seamless integration into existing I²C infrastructure.

FAQ

What is the maximum I²C clock frequency supported by the MCP23008-E/ML?

The MCP23008-E/ML supports three I²C speed grades: 100 kHz (1.8–5.5V), 400 kHz (2.7–5.5V), and 1.7 MHz (4.5–5.5V). The actual maximum depends on VDD level and temperature grade - at 5.0V and +25°C, 1.7 MHz operation is fully characterized and guaranteed per DS20001919F.

Does the MCP23008-E/ML require external pull-up resistors on the I²C bus lines?

Yes, the MCP23008-E/ML requires external pull-up resistors on both SCL and SDA lines. Its I²C interface uses open-drain outputs, and no internal pull-ups are provided. Typical values are 2.2 kΩ to 4.7 kΩ for 100 kHz, and 1 kΩ to 2.2 kΩ for 400 kHz or 1.7 MHz operation, depending on bus capacitance.

How does the interrupt capture register (INTCAP) in the MCP23008-E/ML improve system reliability?

The INTCAP register in the MCP23008-E/ML captures the exact GPIO port state at the instant an interrupt occurs. This eliminates race conditions between interrupt assertion and host read, ensuring deterministic edge detection. Without INTCAP, the host might read a modified port value after the interrupt fires, causing missed or false events - a critical issue in safety-critical or real-time applications using MCP23008-E/ML.

Can the MCP23008-E/ML operate with a 1.8V microcontroller while interfacing with 5V peripherals?

No - the MCP23008-E/ML is not 5V-tolerant on its GPIO pins. All I/O (GP0–GP7), SCL, SDA, and address pins are referenced to VDD. When VDD = 1.8V, absolute maximum input voltage is VDD + 0.6V = 2.4V. Direct connection to 5V signals will violate Absolute Maximum Ratings and risk damage. Level-shifting circuitry is required for mixed-voltage interfacing.

What is the function of the IOCON register's SEQOP bit in the MCP23008-E/ML?

When SEQOP = 0 (default), the MCP23008-E/ML increments its internal address pointer automatically after each byte transfer - enabling efficient sequential register reads/writes (e.g., reading GPIO and OLAT in one transaction). When SEQOP = 1, the address pointer remains static, allowing repeated access to a single register (e.g., polling GPIO without address overhead), which is essential for low-latency status monitoring in the MCP23008-E/ML.