Patent ID: 11936298
Assignee: ROHM CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 10:
11. A drive circuit, which is an N-channel or an NPN type high-side transistor drive circuit, comprising:
a pulse generator, generating a first pulse that becomes high level for a certain period of time in response to a first edge of an input signal and a second pulse that becomes high level for a certain period of time in response to a second edge of the input signal;
a first transistor, being a high breakdown voltage element, and having a gate that receives the first pulse;
a second transistor, being a high breakdown voltage element, and having a gate that receives the second pulse;
a third transistor, disposed between a source and a ground of the first transistor, and having a gate biased by constant voltage;
a fourth transistor, disposed between a source and a ground of the second transistor, and having a gate biased by constant voltage;
a first current mirror circuit, connected to a high-side power supply line and having an input node connected to a drain of the first transistor;
a second current mirror circuit, connected to the high-side power supply line and having an input node connected to a drain of the second transistor;
a first inverter, disposed between the high-side power supply line and a high-side ground line, and having an input node connected to an output node of the first current mirror circuit;
a second inverter, disposed between the high-side power supply line and the high-side ground line, having an input node connected to an output node of the second current mirror circuit and an output node of the first inverter, and having an output node connected to an input node of the first inverter;
a fifth transistor, which is a high breakdown voltage element and has a gate and a grounded source;
an impedance element, disposed between a drain of the fifth transistor and the high-side power supply line;
a sixth transistor, disposed between the high-side power supply line and the drain of the first transistor, and having a gate connected to a node on a low potential side of the impedance element; and
a seventh transistor, disposed between the high-side power supply line and the drain of the second transistor, and having a gate connected to the node on the low potential side of the impedance element.