Patent ID: 6128172
Filing Date: 2000-10-03
Classification: G05F

Abstract:
A thermal protection circuit, comprising:a first voltage supply terminal and a second voltage supply terminal;a first, a second, and a third current source;said third current source having a first transistor with an emitter connection connected to said first voltage supply terminal, a collector connection, and a base connection connected to said collector connection of said first transistor, and having a second transistor with a base connection, a collector connection connected to said collector connection of said first transistor and to said base connection of said first transistor;a voltage divider having a tap, a first voltage divider terminal connected to said second voltage supply terminal, and a second voltage divider terminal connected to said third current source;a third transistor having an emitter connection connected to said second voltage supply terminal, a collector connection connected to said first current source, and a base connection connected to said tap of said voltage divider, a temperature-dependent switching signal being tappable at said collector connection of said third transistor; anda fourth transistor having an emitter connection connected to said second voltage supply terminal, a base connection connected to said second voltage divider terminal, and a collector connection connected to said second current source and to said base connection of said second transistor.