초록 ▼

A switch-control integrated circuit for a switch-mode power supply (SMPS) capable of consistently limiting the peak current value of an output supply voltage irrespective of a temperature change. The circuit includes a switching transistor of the SMPS and a sensing resistor coupled to a drain of the

A switch-control integrated circuit for a switch-mode power supply (SMPS) capable of consistently limiting the peak current value of an output supply voltage irrespective of a temperature change. The circuit includes a switching transistor of the SMPS and a sensing resistor coupled to a drain of the switching transistor for sensing a drain current of the switching transistor to produce a peak current value detection voltage. A voltage generating circuit generates a feedback voltage which varies depending on the temperature condition equal to that of the sensing resistor. A comparator compares the temperature dependent voltage, received at a first input, with the temperature dependent peak current value detection voltage, received at a second input, to produce a temperature independent control signal. A protection circuit, coupled between the comparator and the switching transistor, interrupts the control signal if an abnormal operation of the voltage generating section is detected. Finally, a driving circuit drives the switching transistor in response to the control signal transmitted from the protection circuit.

대표청구항 ▼

[ What is claimed is:] [3.] A temperature dependent feedback circuit for use in an integrated circuit comprising:a first current source for providing a first constant current to a first node;a second current source for providing a second constant current which is less than said first constant curren

[ What is claimed is:] [3.] A temperature dependent feedback circuit for use in an integrated circuit comprising:a first current source for providing a first constant current to a first node;a second current source for providing a second constant current which is less than said first constant current to a second node;a diode coupled forwardly between said first and second nodes;an external capacitor coupled to said second node;an external current sink coupled to said second node; anda dividing resistor, coupled between said first node and ground, for producing a voltage.