Gene Heskett wrote: > I'm still puzzled by the 10 kilohertz response listed for this device. WTH? > Its a GMR device, and GMR is now being used as the read head in modern hard > drives, with data rates recovered from it at what is effectively a 3 > gigahertz rate, so why is this device so darned slow? If I wanted to use it, > I'd sure be calling their applications engineers to get the skinny on why > their device is several thousand times slower. I have done that many times > in the past, and at National Semi in particular, have found their people very > knowledgeable. AMD was at one time similarly helpfull with a memory problem, > and I would expect any semi house to be so if they wanted to win the > design-ins. >
The actual GMR sensor element may be quite fast, but it also produces a millivolt level signal. The amplifier and/or comparator that turns the small signal into a logic level is what determines the overall bandwidth. For a hard drive, they need speed so they use fast circuitry. For a prox switch, speed is not needed, so they use a slower circuit. In fact, I bet they slow it down on purpose - a fast sensor is more likely to respond to noise spikes. Regards, John Kasunich ------------------------------------------------------------------------- SF.Net email is sponsored by: Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
