Patent ID: 6570448
Filing Date: 2003-05-27
Classification: H03F,H03G

Abstract:
A method for correcting start-up deficiencies in an amplifier using a startup mechanism, the amplifier including (i) first and second transistors having sources thereof connected to a first circuit node, and drains thereof respectively forming first and second amplifier output ports and (ii) third and fourth transistors having gates thereof respectively forming first and second amplifier input ports, drains thereof being respectively connected, at least indirectly, to the gates of the first and second transistors, and sources thereof being connected together and forming a second circuit node, a second circuit node voltage being representative of a voltage level of the second circuit node;the startup mechanism including: a comparator having inverting and non-inverting input ports and an output port; and fifth and sixth transistors having (i) gates connected to the comparator output port, (ii) drains respectively connected to the gates of the first and second transistors, and (iii) sources connected to the first circuit node; the method comprising: comparing the second circuit node voltage to a reference voltage; producing a compensating voltage based upon the comparison; and adjusting a voltage of the first and second amplifier output ports in accordance with the compensating voltage.