초록 ▼

A power delivery circuit for supplying load current to a load includes a current switch connected on the high potential side of a load. In order to detect a current condition, such as an over-current condition in the load, a current sensing and detection circuit preferably cooperates with the curren

A power delivery circuit for supplying load current to a load includes a current switch connected on the high potential side of a load. In order to detect a current condition, such as an over-current condition in the load, a current sensing and detection circuit preferably cooperates with the current switch wherein such switch comprises a multicellular device with a plurality of terminals. Such terminals include a first main current terminal connected to a source of high potential, a second main current terminal connecting a majority of device cells to the load, a first auxiliary terminal connected at one end to a minority of device cells so as to provide a current generally proportional to the main device current, and a second auxiliary terminal connected at one end to a majority of device cells. The current detection circuit preferably comprises one branch connected between the first auxiliary terminal and ground and including, in serial circuit, a current-to-voltage converting resistor providing a voltage at one end approximately proportional to the main device current and a bias signal-controlled transimpedance device, and another branch connected between the second auxiliary terminal and ground and providing a bias signal for the transimpedance device in the first branch.

대표청구항 ▼

A current detection circuit in combination with a current controlling device in a power delivery circuit for supplying load current to a load, the current controlling device being multicellular, with a major current-carrying cellular portion and a minor current-carrying cellular portion, a first mai

A current detection circuit in combination with a current controlling device in a power delivery circuit for supplying load current to a load, the current controlling device being multicellular, with a major current-carrying cellular portion and a minor current-carrying cellular portion, a first main current terminal for connection to a source of power, a gate terminal for receiving a control signal, a second main current terminal connecting the major current-carrying cellular portion, a first auxiliary terminal connected at one end to the minor current-carrying cellular portion so as to provide a current generally proportional to the main device current, and a second auxiliary terminal connected at one end to the major current-carrying cellular portion, and wherein the current detection circuit comprises: first and second branches each for connection at one end to a respective one of said first and said second auxiliary terminals and having means for connection in common at the other end to a reference potential in the power delivery circuit; said first branch including a first series-connected semiconductor device; said first branch including a second series-connected semiconductor device; said first semiconductor device operating in a transimpedance mode and being controlled by a bias signal; said second semiconductor device being cross-connected with said first semiconductor device to provide the respective said bias signal thereto; a first node providing a signal approximately proportional to the main device current; and wherein said second semiconductor is connected in said second branch in a manner providing a bias signal for controlling said first semiconductor so as to result in said signal at said node being proportional to the main device current within a relatively small tolerance range across a relatively broad operating range.