Microchip Technology MCP23017T-E/ML

Overview

MCP23017T-E/ML from Microchip Technology is a 16-bit I²C-compatible I/O expander IC with dual 8-bit ports (PORTA and PORTB), supporting 1.8V–5.5V operation, 1.7 MHz I²C interface, and configurable interrupt outputs (INTA/INTB). It provides bidirectional GPIO pins with internal weak pull-ups, polarity inversion, and interrupt-on-change capability - used in microcontroller peripheral expansion for industrial HMI, sensor interface modules, and embedded control panels.

For engineers reviewing the MCP23017T-E/ML datasheet, MCP23017T-E/ML pinout, MCP23017T-E/ML application, or MCP23017T-E/ML equivalent, key selection criteria include I²C speed support (100 kHz / 400 kHz / 1.7 MHz), 28-pin QFN package compatibility, interrupt configuration flexibility (active-high/low/open-drain), low standby current (1 µA max), and AEC-Q100 qualification for automotive-adjacent designs.

Technical Context

The MCP23017T-E/ML implements a register-mapped I²C slave interface with 22 addressable control and data registers, including IODIR, GPIO, OLAT, IPOL, GPINTEN, INTCON, and DEFVAL. Its dual-port architecture supports independent or OR'ed interrupt generation, with glitch-filtered input sampling (150 ns) and interrupt capture latching.

It features hardware address pins (A0–A2) enabling up to eight devices on one I²C bus, a dedicated RESET input with POR circuitry, and configurable bank addressing (IOCON.BANK) for 8-bit or 16-bit register access modes - critical for deterministic timing in real-time embedded systems requiring deterministic I/O state reads/writes.

Key Specifications

Pinout & Package

Package: 28-pin QFN (6 × 6 mm body, exposed thermal pad EP). Pin count and layout match Microchip's standard 28-pin QFN footprint for drop-in PCB compatibility across MCP23X17 variants.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I/O expansion applications.

Compared with PCA9555DWR and MCP23018-E/ML, the MCP23017T-E/ML uniquely combines AEC-Q100 qualification, 1.7 MHz I²C, and interrupt capture - making it optimal for automotive-adjacent industrial systems where reliability, speed, and diagnostic traceability are mandatory.

Availability

MCP23017T-E/ML is available at Aetrix Electronics and suitable for industrial HMI panels, automotive diagnostic tools, and sensor interface modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MCP23017T-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, FPGA, and connectivity solutions, serving industrial, automotive, and communications markets since 1989.

The MCP23017T-E/ML belongs to Microchip's MCP23X17 family of I/O expanders, designed specifically to extend microcontroller GPIO resources over industry-standard serial buses while delivering automotive-grade reliability and flexible interrupt handling.

FAQ

What is the maximum I²C clock frequency supported by the MCP23017T-E/ML?

The MCP23017T-E/ML supports three I²C speed modes: 100 kHz (1.8–5.5V), 400 kHz (2.7–5.5V), and 1.7 MHz (4.5–5.5V). The 1.7 MHz mode requires VDD ≥ 4.5V and fast-rising pull-ups (≤ 1 kΩ) with ≤ 100 pF bus capacitance. This high-speed capability enables efficient data transfer in bandwidth-constrained embedded systems without increasing MCU I/O load.

Does the MCP23017T-E/ML support interrupt-on-change for all 16 GPIO pins?

Yes, the MCP23017T-E/ML supports interrupt-on-change for all 16 GPIO pins (GPA0–GPA7 and GPB0–GPB7) via GPINTENA and GPINTENB registers. Each pin can be individually enabled for interrupt generation, and the INTA/INTB outputs reflect changes relative to either the input port register or a programmable DEFVAL register - providing precise event detection for real-time monitoring applications.

What is the function of the EXPOSED THERMAL PAD (EP) on the MCP23017T-E/ML QFN package?

On the MCP23017T-E/ML QFN package, the exposed thermal pad (EP, Pin 29) must be connected to VSS for optimal thermal performance and electrical stability. Leaving it unconnected degrades thermal resistance and may cause intermittent operation under sustained 25 mA per-pin output loading. Proper soldering of EP to a VSS copper pour significantly improves power dissipation margin in compact industrial enclosures.

Can the MCP23017T-E/ML operate with a 1.8V supply voltage?

Yes, the MCP23017T-E/ML operates from 1.8V to 5.5V across –40°C to +85°C. At 1.8V, it supports 100 kHz I²C mode and retains full register functionality, including interrupt generation and weak pull-up activation (though pull-up current drops to ~40 µA). This makes it compatible with ultra-low-voltage microcontrollers and battery-powered edge devices.

How does the MCP23017T-E/ML handle power-on reset and initialization?

The MCP23017T-E/ML incorporates an internal Power-on Reset (POR) circuit that holds all registers in reset until VDD reaches a valid threshold (VPOR) and rises at ≥ 0.05 V/ms. Upon release, all registers initialize to their POR values (e.g., IODIR = 0xFF, GPIO = 0x00), ensuring predictable startup behavior. The external RESET pin provides synchronous reinitialization without cycling VDD - critical for field-upgrade-safe embedded systems.