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US 7,583,061 B2Granted
Charger circuit and PWM controller thereof
AssigneeBCD Semiconductor Manufacturing Limited
InventorsShu-Zhuang Lu, Tao Peng
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AssigneeBCD Semiconductor Manufacturing Limited
InventorsShu-Zhuang Lu, Tao Peng
Estimating the term…
A PWM controller includes a short circuit mode circuit which has input ends connecting simultaneously to a power supply input end and an output end of an output driving circuit, and an oscillator which has a temperature compensation circuit that includes a medium value multi-transistor resistor of a negative temperature coefficient and a well resistor of a positive temperature coefficient. The invention also provides a charger circuit which includes the PWM controller set forth above and a constant voltage/current control circuit coupling with the PWM controller through a transformer. A system adopting the PWM controller circuit and charger circuit of the invention does not need a voltage stabilization diode now equipped in many conventional designs. The invention provides an improved short circuit protection and eliminates low frequency harmonic waves.
A PWM controller, comprising the characteristic that a short circuit mode circuit has input ends connecting respectively and simultaneously to a power supply input end and an output end of an output driving circuit, and an oscillator which has a temperature compensation circuit which includes a medium value multi-transistor resistor of a negative temperature coefficient and a well resistor of a positive temperature coefficient.
A charger circuit comprising a PWM controller and a constant voltage and constant current control circuit coupled with the PWM controller through a transformer, wherein:
Dependencies are inferred from the claim text.