Current sensing circuit
AssigneeDongbu HiTek Co., Ltd.
InventorsChang-Woo Ha, Jung-Ah Jang
Life of this patent
Estimating the term…
Abstract
A current sensing circuit includes a power transistor, a sensing transistor configured to copy a current flowing through the power transistor at a predetermined ratio, a current sensing resistor configured to detect a voltage from the current copied by the sensing transistor, an input resistor configured to convert an input voltage to a current, a cross self-biasing cascade block configured to adjust currents at both ends of the input resistor, and a common gate transistor and a reference resistor configured to convert a current output of the input resistor to a final sense voltage.
Claims20
An apparatus comprising:
- a power transistor;
- a sensing transistor configured to copy a current flowing through the power transistor at a predetermined ratio;
- a current sensing resistor configured to detect a voltage from the current copied by the sensing transistor;
- an input resistor configured to convert an input voltage to a current;
- a cross self-biasing cascade block configured to adjust currents at both ends of the input resistor;
- and
- a common gate transistor and a reference resistor configured to convert a current output of the input resistor to a final sense voltage.
An apparatus comprising:
- a main power transistor that corresponds to a main power switch to perform a switching operation;
- a sensing transistor that copies a current flowing through the main power transistor at a predetermined ratio;
- a current sensing resistor that detects the current copied by the sensing transistor into a voltage;
- an input resistor including a first resistor and a second resistor, the input resistor converting an input voltage to a current;
- a cross self-biasing cascade block that equally adjusts the current to flow through both ends of the first and second resistors;
- a current source that is an end-to-end current source of the input resistor;
- a common gate transistor including a common gate amplifier;
- and
- a reference resistor that converts the current output from the input resistor to a final output voltage that represents a final sense voltage,
- wherein the common gate transistor delivers a single current output from the input resistor to the reference resistor.
An apparatus comprising:
- a first field effect transistor that corresponds to a main power switch and also performs a switching operation;
- a second field effect transistor that copies a current flowing through the first field effect transistor at a predetermined ratio;
- a current sensing resistor that detects the current copied by the second field effect transistor into a voltage;
- an input resistor including a first resistor and a second resistor connected to each other in parallel, the input resistor converting an input voltage to a current;
- a cross self-biasing cascade block that equally adjusts the current to flow through both ends of the first and second resistors;
- a current source that is an end-to-end current source of the input resistor;
- a common gate transistor comprising a common gate amplifier;
- and
- a reference resistor that converts the current output from the input resistor to a final output voltage that represents a final sense voltage,
- wherein the common gate transistor delivers a single current output from the input resistor to the reference resistor.
Dependencies are inferred from the claim text.