Power drive circuit
AssigneeRohm Co., Ltd.
InventorToshiro Okubo
Life of this patent
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Abstract
A balanced transformer-less (BTL) power drive circuit comprises a push-pull type output transistor section connected with a main power supply PowVcc, and an input control section connected with an auxiliary power supply for providing the output transistor section with a control signal. The potential of the auxiliary power supply is selectively set equal to or above the supply potential of the main power supply, depending on the requirements for the dynamic range of the power drive circuit. In accord with the potential of the auxiliary power supply thus set, the output reference potential Vref is set to the medium of the dynamic range, thereby ensuring the linearity of the input-output characteristic of the drive circuit, irrespective of the selected level of the auxiliary power supply.
Claims4
A power drive circuit including:
- a first push-pull type output transistor section connected between a main power supply having a potential and a ground;
- a first input control section, connected between an auxiliary power supply having a potential and said ground, for receiving an input signal and an output reference potential to provide said first push-pull type output transistor section with a first control signal;
- a second push-pull type output transistor section connected between said main power supply and said ground;
- a second input control section connected between said auxiliary power supply and said ground, for receiving said output reference potential and an inverted input signal, which is an inversion of said input signal, to provide said second push-pull type output transistor section with a second control signal,
- wherein each of said first and said second output transistor sections provides one of two different dynamic ranges, a first dynamic range for a first mode where said potential of said auxiliary power supply is equal to said potential of said main power supply and a second dynamic range for a second mode where said potential of said auxiliary power supply is higher than said potential of said main power supply;
- and
- said power drive circuit wherein said output reference potential matches the medium of the dynamic ranges of said first and second output transistor sections.
Dependencies are inferred from the claim text.