Efficient buck topology DC-DC power stage utilizing monolithic N- channel upper FET and pilot current sensing
AssigneeIntersil Americas Inc.
InventorsGreg J. Miller, Michael M. Walters
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Abstract
A power switching stage architecture for a buck topology-based, DC-DC converter includes an upper power switching N-channel device FET integrated in the same semiconductor circuit chip with the switching driver, while a lower power switching is also an N-channel FET, but is external to the driver chip. Either of the two power switching FETs may be configured to include a pilot FET cell, to facilitate current sensing for the controller.
Claims9
In an apparatus for generating a regulated direct current (DC) output voltage, said apparatus including a buck topology-based, DC-DC converter coupled to a supply voltage, and being operative to generate a regulated output voltage derived from said supply voltage, said DC-DC converter having a pulse width modulation (PWM) generator which generates a PWM switching signal for application to a switching circuit driver, that switchably controls operation of a switching circuit containing upper and lower power switching NFET devices coupled between respective first and second power supply terminals, a common node thereof being coupled through an inductor element to an output voltage terminal, and a controller for controlling the operation of said PWM generator,
- the improvement wherein
- said upper power switching NFET device is formed in a common integrated circuit with said switching circuit driver, and said lower power switching NFET device is external to said common integrated circuit.
A method of configuring a buck topology-based, DC-DC converter that is operative to generate a regulated output voltage derived from a supply voltage, said method comprising the steps of:
- (a) providing a pulse width modulation (PWM) generator which generates a PWM switching signal for application to a switching circuit driver, that switchably controls operation of a switching circuit containing upper and lower power switching NFET devices coupled between respective first and second power supply terminals, a common node thereof being coupled through an inductor element to an output voltage terminal, and a controller for controlling the operation of said PWM generator;
- (b) integrating said upper power switching NFET device in a common integrated circuit with said switching circuit driver;
- and
- (c) providing said lower power switching NFET device external to said common integrated circuit.
A DC-DC converter for generating a regulated output voltage derived from a supply voltage, comprising:
- a pulse width modulation (PWM) generator which generates a PWM switching signal for application to a switching circuit driver, that switchably controls operation of a switching circuit containing upper and lower power switching NFET devices coupled between respective first and second power supply terminals, a common node thereof being coupled through an inductor element to an output voltage terminal;
- and
- a controller for controlling the operation of said PWM generator;
- and wherein
- said upper power switching NFET device is formed in a common integrated circuit with said switching circuit driver, and said lower power switching NFET device is external to said common integrated circuit.
Dependencies are inferred from the claim text.