Switch mode power supply for envelope tracking

摘要

There is disclosed an envelope tracked power supply comprising a high bandwidth, low delay closed loop switch mode power supply stage comprising: a pulse width modulator for generating a width modulated pulse in dependence on an input signal and an output voltage of the switch mode power supply stage; a wideband transformer, having a winding of a first side connected to receive the modulated pulse, and a winding of a second side; and an output stage connected to the winding of the second side of the transformer, and for generating the output voltage in dependence on the modulated pulse induced in the winding of the second side.

主权项

1. An envelope tracked power supply comprising a high bandwidth, low delay closed loop switch mode power supply stage, comprising:
a single pulse width modulator for generating a width modulated pulse in dependence on an input signal and an output voltage of the switch mode power supply stage; a single wideband transformer, having a winding of a first side connected to receive the modulated pulse, and first and second windings of a second side; a first transistor having a conductive path connected between a first supply voltage and an output of the switch mode power supply stage; a second transistor having a conductive path connected between a second supply voltage and the output of the switch mode power supply stage; and an anti-shoot-through circuit comprising:
a first circuit comprising:
a third transistor connected to receive a modulated pulse induced in the first winding of the second side of the transformer at a control node of the third transistor; anda fourth transistor connected to receive the modulated pulse induced in the first winding of the second side of the transformer at a control node of the fourth transistor, wherein an emitter of the third transistor and an emitter of the fourth transistor are connected with a control node of the first transistor; anda second circuit comprising:
a fifth transistor connected to receive a modulated pulse induced in the second winding of the second side of the transformer at a control node of the fifth transistor; anda sixth transistor connected to receive the modulated pulse induced in the second winding of the second side of the transformer at a control node of the sixth transistor, wherein an emitter of the fifth transistor and an emitter of the sixth transistor are connected with a control node of the second transistor.