USB2251-NU-06

Specialized Overview

The Microchip USB2251-NU-06 is a USB 2.0 compliant, Hi-Speed mass storage class peripheral controller designed for reading and writing to flash media formats including CompactFlash, SmartMedia, Memory Stick, Secure Digital, and MultiMediaCard. It features an integrated 8051 8-bit microprocessor operating at 60 MHz with 64 KB ROM and 14 KB RAM. The device supports multiple simultaneous card insertions and flexible Logical Unit Number (LUN) assignment. It operates within the commercial temperature range of 0°C to +70°C and utilizes a 128-pin VTQFP package.

Specialized Feature Summary

• Integrated hardware-controlled data flow architecture for self-mapped media
• Supports pipelined hardware access for non-self-mapped media
• Includes four independent internal card power FETs with short circuit protection
• Provides OEM selectable vendor, product, and serial number identification

Specialized Applications

• Flash Media Card Readers/Writers
• Printers
• Desktop and Mobile PCs
• Consumer A/V Equipment
• Media Players/Viewers

Specialized Procurement Notes

Verify the specific ordering suffix against the manufacturer's current Product Identification System documentation to confirm package type and temperature grade. Ensure that any external configuration components, such as EEPROMs for custom firmware or identifiers, are compatible with the device's I2C interface requirements. Confirm that the design supports the required voltage levels for the 3.3V power domain and 1.8V core operation.

Specialized Selection Notes

Select the USB2251 variant when xD-Picture Card support is not required, as this format is explicitly excluded from this model compared to the USB2250. Consider the commercial temperature range limits if the application environment exceeds 70°C, in which case the industrial 'i' version should be evaluated. Ensure the host system can support the high-speed transfer rates enabled by the integrated PHY and transaction translators.

Specialized Part Context

This component belongs to the USB2250/50i/51/51i family of ultra-fast USB 2.0 multi-slot flash media controllers. The USB2251 specifically excludes xD-Picture Card compatibility while maintaining support for other major flash standards. It serves as a single-chip solution for combo media sockets, integrating the USB interface engine, flash media controllers, and an embedded processor to reduce board space and component count.

Specialized Replacement Considerations

The USB2250I-NU-06 is a functional substitute within the same family, offering identical capabilities plus support for xD-Picture Cards. Both devices share the same 128-pin VTQFP package and pinout, allowing for potential direct replacement if xD support is needed or available.