USB2642/ML

Specialized Overview

The USB2642 is a single-chip USB 2.0 high-speed hub and flash media card controller combo solution by Microchip Technology. It integrates two downstream USB ports and a dedicated SD/MMC interface internally connected as the third port of a USB compound device. The controller supports Secure Digital (SD, SDHC, SDXC), MultiMediaCard (MMC), and embedded MMC formats with storage addressability up to 2TB. It features an I2C over USB bridge for peripheral control and includes programmable features such as PortMap, PortSwap, and PHYBoost. The device operates on a single 24 MHz crystal and supports both commercial (0°C to +70°C) and industrial (-40°C to +85°C) temperature ranges in a 48-pin QFN package.

Specialized Feature Summary

• Integrated USB 2.0 hub controller with two exposed high-speed downstream ports and a dedicated flash media reader attached as a third internal port.
• Supports multiple flash media formats including SD, SDHC, SDXC, MMC, and eMMC with sustained transfer rates exceeding 35 MB/s.
• Includes an I2C over USB bridge allowing host-controlled access to I2C slave devices operating at 50 kHz.
• Features programmable design aids: PortMap for flexible port mapping, PortSwap for differential pair alignment, and PHYBoost for signal integrity recovery.

Specialized Applications

• Desktop and mobile PCs
• Monitors and televisions
• Mobile PC docking stations
• Consumer audio/video equipment
• Flash media card readers/writers

Specialized Procurement Notes

Verify the specific ordering suffix against the manufacturer's current product identification system to ensure correct temperature range and package variant. Confirm that external configuration requirements, such as SPI ROM or I2C EEPROM, align with the target application's firmware strategy. Check for any applicable errata sheets associated with the silicon revision before finalizing procurement specifications.

Specialized Selection Notes

Select the USB2642 when a combined hub and card reader solution is required to reduce component count and PCB space. Ensure the design accommodates the 48-pin QFN package and provides a 24 MHz clock source. Consider the need for external SPI Flash EEPROM if custom vendor/product IDs or external code execution are required. Verify power management needs for individual versus ganged port control.

Specialized Part Context

The USB2642 belongs to Microchip's family of USB interface integrated circuits designed for high-speed data transfer and peripheral expansion. It complements other USB controllers by offering a specialized combination of hub functionality and mass storage interface capabilities. This integration simplifies system architecture for devices requiring both connectivity expansion and direct flash media access.

Specialized Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Consult Microchip Technology directly for current alternative recommendations or updated series replacements.

Specialized FAQ

How does the USB2642 handle the flash media reader connection?

The dedicated flash media reader is internally attached to the hub's third downstream port as a USB compound device, appearing as a single logical unit to the host.

What is the purpose of the PortSwap feature?

PortSwap allows programmable selection of USB differential-pair pin locations, enabling direct alignment of USB signals to connectors to simplify PCB layout and avoid trace crossing.

Can the USB2642 operate without an external configuration device?

Yes, the device loads default settings from internal firmware after a reset. However, it can also be configured using an external SPI ROM or I2C EEPROM for custom IDs and code execution.