Abstract: Thermal overload protection circuitry 14 for an automotive ignition system includes a gate drive circuit (18) responsive to a control signal (ESTB) to produce a drive signal (VGD) for driving a power switching device (22) separate from the protection circuitry (14), and a thermal overload protection circuit (40) configured to supply a first current (I1) to a thermal sensing component (38) associated with, and having an operating temperature defined by, the power switching device (22), wherein the first current (I1) has a magnitude defined by the operating temperature of the thermal sensing component (38). The first current is multiplied by a current controlled current source (60) to produce a second current (I2), and the second current is used to limit the drive signal (VGD) to thereby maintain the operating temperature of the power switching device (22) below an operating temperature limit.

Abstract: An interface for providing thermal overload protection includes a switching device, a temperature indicating device, a drive circuit and a thermal monitoring circuit. The thermal monitoring circuit is coupled across the temperature indicating device and provides a shutdown signal to the drive circuit when the temperature of the switching device is above a predetermined temperature level as indicated by a temperature signal provided by the temperature indicating device. The drive circuit responds to the shutdown signal by removing current sources and current sinks from a control terminal of the switching device at which point leakage currents cause the switching device to reduce a drive current to an inductive load.

Abstract: An integrated circuit (10) includes a thermal sensing device (20) and a power-switching device (12) such as an IGBT. The power device (12) is fabricated in a conventional manner on a semiconductor substrate, and the thermal sensing device (20) is fabricated on an electrical insulation layer (74) formed over the substrate. The thermal sensing device (20) may be provided in the form of a number of series-connected polysilicon diodes (D1-D3) positioned adjacent to the power device (12) such that the operating temperature of the thermal sensing device (20) is near that of the power device (12). In response to an input current IC, the thermal sensing device (20) produces an output voltage (VD) that is substantially linear with surface die temperature, and which reacts rapidly to changes in surface die temperature. The thermal sensing device (20) is completely electrically isolated from the power device, thereby eliminating any electrical interaction therebetween.

Abstract: An apparatus and method for measuring leakage current between a first semiconductor region and a second semiconductor region to be formed therein includes a system for measuring surface minority carrier leakage within the first semiconductor region. A correlation is established between surface minority carrier lifetime in the first semiconductor region and leakage current between the first and second semiconductor regions, and in one embodiment a surface minority carrier lifetime threshold is designated based on this correlation. Leakage current between the first and second regions is acceptable if the measured surface minority carrier lifetime is greater than this threshold. In an alternate embodiment, a leakage current threshold is established, and the measured surface minority carrier leakage is converted via the correlation to a measured leakage current.

Abstract: Thermal overload protection circuitry 14 for an automotive ignition system includes a gate drive circuit (18) responsive to a control signal (ESTB) to produce a drive signal (VGD) for driving a power so itching device (22) separate from the protection circuitry (14), and a thermal overload protection circuit (40) configured to supply a first current (I1) to a thermal sensing component (38) associated with, and having an operating temperature defined by, the power switching device (22), wherein the first current (I1) has a magnitude defined by the operating temperature of the thermal sensing component (38). The first current is multiplied by a current controlled current source (60) to produce a second current (I2), and the second current is used to limit the drive signal (VGD) to thereby maintain the operating temperature of the power switching device (22) below an operating temperature limit.

Abstract: An integrated circuit (10) includes a thermal sensing device (20) and a power-switching device (12) such as an IGBT. The power device (12) is fabricated in a conventional manner on a semiconductor substrate, and the thermal sensing device (20) is fabricated on an electrical insulation layer (74) formed over the substrate. The thermal sensing device (20) may be provided in the form of a number of series-connected polysilicon diodes (D1-D3) positioned adjacent to the power device (12) such that the operating temperature of the thermal sensing device (20) is near that of the power device (12). In response to an input current IC, the thermal sensing device (20) produces an output voltage (VD) that is substantially linear with surface die temperature, and which reacts rapidly to changes in surface die temperature. The thermal sensing device (20) is completely electrically isolated from the power device, thereby eliminating any electrical interaction therebetween.

Abstract: An apparatus and method for measuring leakage current between a first semiconductor region and a second semiconductor region to be formed therein includes a system for measuring surface minority carrier leakage within the first semiconductor region. A correlation is established between surface minority carrier lifetime in the first semiconductor region and leakage current between the first and second semiconductor regions, and in one embodiment a surface minority carrier lifetime threshold is designated based on this correlation. Leakage current between the first and second regions is acceptable if the measured surface minority carrier lifetime is greater than this threshold. In an alternate embodiment, a leakage current threshold is established, and the measured surface minority carrier leakage is converted via the correlation to a measured leakage current.

Abstract: A protective circuit having enhanced and accurate thermal shutdown temperatures. The protective circuit establishes the thermal shutdown temperature within a predetermined range and provides an output signal when the thermal shutdown temperature is exceeded. The protective circuit, in one embodiment, comprises a current generator for supplying a predetermined collector current I.sub.c1, a current mirror arrangement for supplying a collector current I.sub.c2 which has a mirror response to that of the collector current I.sub.c1, a resistor arranged to have the mirror collector current I.sub.c2 flowing therethrough, and the combination of a resistor and a bipolar transistor serving as a thermal sensor. The current generator comprises at least a pair of bipolar transistors selected from one of the NPN and PNP types with each of said pair operating with different current densities. The base electrodes of the pair are interconnected by a resistor. The collector current I.sub.