Patent ID: 7372312
Filing Date: 2008-05-13
Classification: H03K

Abstract:
1. A pulse width modulation (PWM) generating circuit comprising: a voltage input; a first comparator having a non-inverting input, an inverting input, and an output; a first resistor and a second resistor connected in series between the voltage input and ground, a node between the first resistor and the second resistor connected to the non-inverting input of the first comparator; a third resistor, a fourth resistor, and a capacitor connected in series between the voltage input and ground, a node between the fourth resistor and the capacitor connected to the inverting input of the first comparator, and a node between the third resistor and the fourth resistor connected to the output of the first comparator; a diode having an anode connected to the non-inverting input of the first comparator, and a cathode connected to the output of the first comparator; and a second comparator having a non-inverting input receiving a reference voltage, an inverting input connected to the inverting input of the first comparator, and an output connected to the voltage input via a fifth resistor, the output of the second comparator outputting PWM signals.