Bias supply selection circuit, method of operation thereof and power supply employing the same
First Claim
1. A bias supply selection circuit employable with a linear regulating device configured to provide a first bias supply voltage and a main bias supply stage configured to provide a second bias supply voltage, comprising:
- a voltage monitoring circuit configured to monitor a level of said second bias supply voltage and to provide a control voltage proportional to said level; and
a controllable switching circuit, coupled to said voltage monitoring circuit, configured to select said second bias supply voltage by deactivating said linear regulating device when said control voltage reaches a predetermined value.
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Accused Products
Abstract
The present invention provides a bias supply selection circuit employable with a linear regulating device configured to provide a first bias supply voltage and a main bias supply stage configured to provide a second bias supply voltage. In one embodiment, the bias supply selection circuit includes a voltage monitoring circuit configured to monitor a level of the second bias supply voltage and to provide a control voltage proportional to the level. Additionally, the bias supply selection circuit includes a controllable switching circuit, coupled to the voltage monitoring circuit, configured to select the second bias supply voltage by deactivating the linear regulating device when the control voltage reaches a predetermined value.
21 Citations
21 Claims
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1. A bias supply selection circuit employable with a linear regulating device configured to provide a first bias supply voltage and a main bias supply stage configured to provide a second bias supply voltage, comprising:
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a voltage monitoring circuit configured to monitor a level of said second bias supply voltage and to provide a control voltage proportional to said level; and
a controllable switching circuit, coupled to said voltage monitoring circuit, configured to select said second bias supply voltage by deactivating said linear regulating device when said control voltage reaches a predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of operating a bias supply for use with a linear regulating device that provides a first bias supply voltage and a main bias supply stage that provides a second bias supply voltage, comprising:
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monitoring a level of said second bias supply voltage;
providing a control voltage proportional to said level; and
selecting said second bias supply voltage by deactivating said linear regulating device when said control voltage reaches a predetermined value. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A switching power supply, comprising:
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a primary power supply circuit having a main switch and coupled to a transformer;
a secondary power supply circuit coupled to said transformer;
a bias supply circuit, coupled to said transformer, that employs a linear regulating device to provide a first bias supply voltage and a main bias supply stage to provide a second bias supply voltage; and
a bias supply selection circuit coupled to said bias supply circuit, including;
a voltage monitoring circuit that monitors a level of said second bias supply voltage and provides a control voltage proportional to said level; and
a controllable switching circuit, coupled to said voltage monitoring circuit, that selects said second bias supply voltage by deactivating said linear regulating device when said control voltage reaches a predetermined value. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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Specification