Solid state switch with temperature compensated current limit
OwnerDaniel Segarrainventor
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Abstract
The present invention relates to a circuit and method of providing a voltage having a temperature independent current compliance to a load. The circuit includes a first resistive element having a temperature dependent resistivity, a second resistive element, an amplifier, a current module generating a temperature dependent current, and a load current controller. Temperature dependent voltages developed across the resistive elements track each other to enable a constant current limit over a wide temperature range.
Claims16
A temperature compensated current limit circuit comprising:
- a first resistive element having a first terminal and a second terminal, said first terminal adapted to receive an input voltage, said first resistive element having a temperature dependent resistivity;
- a second resistive element having a first terminal and a second terminal, said first terminal adapted to receive said input voltage;
- a load current controller having a first terminal in communication with said second terminal of said first resistive element, a second terminal in communication with a load, and a control terminal adapted to receive a control signal;
- a current module having a first terminal in communication with said second terminal of said second resistive element, said current module providing a temperature dependent current at said first terminal;
- and
- an amplifier having a first input terminal in communication with said second terminal of said first resistive element, a second input terminal in communication with said second terminal of said second resistive element, and an amplifier output terminal in communication with said control terminal of said load current controller, said amplifier providing said control signal at said amplifier output terminal in response to a load current, said resistivity of said first resistive element, said resistivity of said second resistive element and said temperature dependent current.
A method for providing a voltage across a load, said voltage having a temperature independent current compliance, comprising:
- generating a first temperature dependent voltage in response to a current through said load;
- generating a second temperature dependent voltage drop-in response to a temperature dependent reference current;
- applying said first temperature dependent voltage to both an amplifier and a load current controller;
- amplifying the difference of said first temperature dependant voltage and said second temperature dependent voltage to generate a control signal;
- and
- applying said control signal to said load current controller to provide said voltage having a temperature independent current compliance across said load.
A method for providing a voltage across a load, said voltage having a temperature independent current compliance, comprising:
- applying a first temperature dependent voltage to both an amplifier and a load current controller;
- comparing said first temperature dependant voltage to a second temperature dependent voltage, wherein said second temperature dependent voltage is responsive to a temperature dependent current;
- generating a control signal in response to said comparison;
- and
- generating said voltage having a temperature independent current compliance in response to said control signal.
A temperature compensated current limit circuit comprising:
- means for determining a difference between a first temperature dependent voltage and a second temperature dependent voltage, said second temperature dependent voltage being responsive to a temperature dependent current;
- means for supplying said first temperature dependent voltage to both a load current controller and said means for determining a difference;
- means for generating a control signal in response to said difference;
- and
- means for applying a voltage having a temperature independent current compliance across a load in response to said control signal.
Dependencies are inferred from the claim text.