Dimensions of ExpressCard
Current CardBus PC cards are 54 millimeters wide. ExpressCard can divided into two cate- gories, based on width. Most designs will use the ExpressCard 34 design, which sets the width at 34 millimeters. For some applications, the wider ExpressCard 54 standard will be used to produce cards that can handle the higher thermal requirements of those applications.
All ExpressCard modules are 5mm thick but the standard also allows for card developers to build longer 'extended' modules.
Native Bus Connection
The ExpressCard standard supports both the USB 2.0 and PCI Express interfaces. Card manufacturers are able to choose whichever bus is appropriate to their application; the per- formance of PCI Express, or from the wide range of solutions supported by USB. All host PC ExpressCard slots will support cards using either interface. The host platform no longer needs to incorporate a bridge chip between the chipset and the socket. PCI Express and USB 2.0 are fully
To support the broadest range of applications there are two sizes of module. Both are smaller that today's CardBus card. The smallest card, the ExpressCard/34 module, is almost half the size of a CardBus card. This size is suited to a very broad range of applications covering communications, media, and general purpose.
