Patent ID: 6201427
Filing Date: 2001-03-13
Classification: H03K

Abstract:
Circuitry for protecting a load driving device from a reverse voltage condition, comprising:a current drive device fabricated within a n-type silicon region formed on a p-type silicon substrate and surrounded by a p-type isolation region extending into said substrate, said n-type silicon region defining a drain of said drive device;a first protection device connected between said isolation region and a reference node; anda second protection device connected between said isolation region and said drain of said drive device, said first protection device isolating said isolation region from said reference node and said second protection device coupling said isolation region to said drain of said drive device when a first voltage defined at said drain of said drive device is negative with respect to a reference potential defined at said reference node, said first protection device coupling said isolation region to said reference node and said second protection device isolating said isolation region from said drain of said drive device when said first voltage is positive with respect to said reference potential.