Power amplifier with multiple switched output stages, and method and driver for operating same
AssigneeSiemens Aktiengesellschaft
InventorPeter Schweighofer
Life of this patent
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Abstract
In a method for the drive of a number of coupled output stages drive signals for the output stages are generated. Given an over-voltage condition in one of the output stages, the output stage affected by the over-voltage condition is switched into a charge output mode for a limited time duration and at least one other output stage is switched into a charge pick-up mode for a limited time. This method is utilized in the operation of a control module and of a power amplifier, and achieves a charge compensation or balancing or equalization between the output stages with very little circuit-oriented outlay.
Claims12
A method for operating a power amplifier having a plurality of switched output stages, each of said output stages including a charging capacitor, said method comprising the steps of:
- identifying an over-voltage condition in one of said output stages by measuring an intermediate circuit voltage across the charging capacitor of that output stage;
- switching said one of said output stages affected by said over-voltage condition into a charge output mode in which charge is supplied as an output of said one of said output stages for a limited time duration by supplying drive signals to said one of said output stages;
- switching at least one other of said output stages into a charge pick-up mode in which charge is picked up by said at least one other of said output stages for a limited time duration by means of drive signals supplied to said at least one other of said output stages;
- and
- coupling said plurality of output stages so that energy supplied as an output by said one of said output stages in the charge output mode is picked-up by said at least one other of said output stages switched into said charge pick-up mode.
A control mode for driving an output stage of a power amplifier, said output stage including a charging capacitor and being operable in a normal mode and in a charge output mode in which charge is supplied as an output stage, said control module comprising:
- at least one sampling input for determining an over-voltage condition of said output stage by measuring an intermediate circuit voltage across said charging capacitor of said output stage;
- and
- means responsive to an identification of said over-voltage condition for supplying a signal to a discharge signal output for switching said output stage from said normal mode into said charge output mode for a limited time duration.
A power amplifier comprising:
- a plurality of output stages, each output stage including a charging capacitor, and each output stage being operable in a normal mode, a charge output mode in which charge is supplied as an output of said output stage, and a charge pick-up mode in which charge is picked up by said output stage;
- control means for identifying an over-voltage condition in any of said output stages by measuring an intermediate circuit voltage across the charging capacitor of that output stage;
- and
- said control means including means, upon an identification of an over-voltage condition in one of said output stages, for switching said one of said output stages from said normal mode to said charge output mode for a limited time duration and for switching another one of said output stages from said normal mode into said charge pick-up mode for a limited time duration.
Dependencies are inferred from the claim text.