MCP23017-E/SO is a 16-bit GPIO expansion chip from Microchip — only 2 microcontroller pins needed via I2C to expand 16 independently configurable IO ports, greatly reducing system complexity and cost.

Each IO pin supports 1.8V~5.5V independent voltage levels (independent of VCC), bridging different voltage systems without external level-shifters. The chip supports hardware interrupts with per-pin independent configuration for interrupt-on-change or interrupt-compare mode, significantly reducing MCU polling and improving system response speed.

MCP23017 configures I2C address via 3 address pins (A0/A1/A2); up to 8 chips can share the same I2C bus, expanding to 128 IO ports. The chip uses SOP-28 wide-body package with built-in power-on reset (POR) and watchdog timer, mit Unterstützung für both 100kHz and 400kHz I2C speed modes.

MCP23017-E/SO uses SOP-28 package (Small Outline Gehause, 28 pins, wide body 1.27mm pin pitch). Gull-wing pins are suitable for standard SMT processes, facilitating visual solder joint inspection. Gehause dimensions 7.5mm x 17.9mm — appropriate for applications with adequate PCB space.

MCP23017 uses 8-column x 4-row pin arrangement with 1.27mm pin pitch, compatible with standard SOIC processes. Pins are grouped by function: VCC/GND (power), SCL/SDA (I2C interface), hardware address pins (A0/A1/A2), interrupt outputs (INT-A/INT-B), and 16 GPIO (GP0~GP15, split into Port A and Port B).

• GP0~GP7 (Port A)：8 configurable GPIO pins. Each pin direction (input/output) configured via IODIRA register. Each pin has optional weak pull-up (100kΩ).
• GP8~GP15 (Port B)：Second group of 8 GPIO pins, electrically identical to Port A. Direction independently configured via IODIRB register.
• SCL (Pin 15): I2C Clock：I2C serial clock input, provided by master device (MCU). Clock frequency supports 100kHz (standard mode) and 400kHz (fast mode).
• SDA (Pin 14): I2C Data：I2C serial data pin, open-drain output, requires external pull-up resistor (recommended 4.7kΩ~10kΩ).
• A0/A1/A2 (Pins 18/17/16): Hardware Address：3-bit address configuration pins — set device I2C address by connecting to GND (low) or VCC (high). Up to 8 MCP23017 chips can share the same I2C bus.
• INT-A/INT-B (Pins 20/19): Interrupt Output：Two open-drain interrupt output pins corresponding to Port A and Port B interrupt events respectively. Connect to MCU external interrupt pins.

Die folgenden Alternativen dienen nur als Referenz. Bitte vor Auswahl die Kompatibilitat prufen.

Gehause Comparison

Microchip Technology Inc. (NASDAQ: MCHP)'s IO expansion product line includes a complete range from 8-bit to 16-bit, I2C to SPI. MCP23017 series is one of its most popular 16-bit GPIO expansion chips, häufig in passenden Elektronik-Anwendungen eingesetzt.

Microchip provides complete reference code, driver libraries and application notes to help engineers quickly complete IO expansion designs, plus the Microchip Xpress development board and MPLAB X IDE for convenient development and debugging.