Linear power amplifier with a pulse density modulated switching power supply

摘要

A linear power amplifier having a pulse density modulated switching power supply including a power supply providing at least a relatively high DC voltage output; a voltage amplifier connected to an external signal source to amplify a relatively low voltage signal received from the external signal source into a relatively high voltage signal; a current amplifier connected to the voltage amplifier to increase the current flow associated with the relatively high voltage signal, as needed, in order to properly drive a load, wherein the current amplifier is powered by a pulse generator. The pulse generator is connected to a first line carrying the relatively high voltage signal to the load, and to a second line supplying power to the current amplifier. The pulse generator (i) compares the instantaneous voltage amplitude of the relatively high voltage signal with the instantaneous voltage level powering the current amplifier, (ii) provides fixed duration pulses, at the relatively high DC voltage, to power the current amplifier whenever, and so long as, the instantaneous voltage amplitude of the relatively high voltage signal rises high enough relative to the instantaneous voltage level powering the current amplifier to cause the current amplifier to approach saturation, (iii) compares the instantaneous voltage level powering the current amplifier with an internal reference voltage standard, and (iv) provides fixed duration pulses at the relatively high DC voltage to power the current amplifier whenever, and for so long as, the instantaneous voltage level powering the current amplifier is less than the internal reference voltage standard.