Current generator with thermal protection

Current generator with thermal protection having an input terminal and an output terminal, said current generator comprising:

• a voltage generator;
• a first controlled switch having a control terminal applied to said voltage generator, a first terminal connected to said input terminal, and a second terminal connected to a resistance;
• a second controlled switch having a control terminal coupled to said voltage generator, a first terminal connected to said resistance, and a second terminal connected to said output terminal;
• a temperature sensor of said current generator able to measure the temperature of said current generator;
• a control circuit of said second controlled switch able to open said second controlled switch in the case in which the temperature of said current generator overcomes a preset temperature;
• and
• a third transistor having a control terminal coupled to said second terminal of said first controlled switch, a first terminal connected to said control terminal of said second controlled switch, and a second terminal connected to said output terminal.

Current generator with thermal protection having an input terminal and an output terminal, said current generator comprising:

• a voltage generator;
• a first controlled switch having a control terminal applied to said voltage generator, a first terminal connected to said input terminal, and a second terminal connected to a resistance;
• a second controlled switch having a control terminal coupled to said voltage generator, a first terminal connected to said resistance, and a second terminal connected to said output terminal;
• a temperature sensor of said current generator able to measure the temperature of said current generator;
• a control circuit of said second controlled switch able to open said second controlled switch in the case in which the temperature of said current generator overcomes a preset temperature;
• a current mirror;
• and
• a hysteresis generating circuit comprising a transistor having a control terminal coupled to said temperature sensor, a first terminal connected to a branch of said current mirror, and a second terminal connected to said output terminal,
• wherein the other branch of said current mirror is coupled to said temperature sensor as to raise a voltage proportionally to the temperature of said current generator.

Pulse width modulation power supply comprising:

• a current generator used as start-up circuit, said current generator including:
• a voltage generator;
• a resistance having first and second terminals;
• a first controlled switch having first and second terminals and a control terminal, the control terminal being coupled to said voltage generator, the first terminal being connected to said input terminal, and the second terminal being connected to the first terminal of said resistance;
• a second controlled switch having first and second terminals and a control terminal, the control terminal being coupled to said voltage generator, the first terminal being connected to the second terminal of said resistance, and the second terminal being connected to said output terminal;
• a temperature sensor coupled to said current generator for measuring the temperature of said current generator;
• and
• a control circuit coupled to said second controlled switch and said temperature sensor, said control circuit opening said second controlled switch when said temperature sensor indicates that the temperature of said current generator is above a preset temperature.

An integrated circuit including at least one current generator comprising:

• a voltage generator;
• a resistance having first and second terminals;
• a first controlled switch having first and second terminals and a control terminal, the control terminal being coupled to said voltage generator, the first terminal being connected to said input terminal, and the second terminal being connected to the first terminal of said resistance;
• a second controlled switch having first and second terminals and a control terminal, the control terminal being coupled to said voltage generator, the first terminal being connected to the second terminal of said resistance, and the second terminal being connected to said output terminal;
• a temperature sensor coupled to said current generator for measuring the temperature of said current generator;
• and
• a control circuit coupled to said second controlled switch and said temperature sensor, said control circuit opening said second controlled switch when said temperature sensor indicates that the temperature of said current generator is above a preset temperature.