Circuit for current injection control in analog switches

A circuit for current injection control comprising:

• a control signal suitable for controlling the operation of a first switch, consisting of a first transistor and a second transistor, the latter having a polarity opposite to said first transistor;
• a second switch, consisting of third and fourth transistors of equal polarity to said first and second transistors respectively, controlled by said control signal and connected to said first switch, so that drain electrodes of said first switch are common with source electrodes of said second switch;
• and
• a fifth and a sixth transistor polarized in the conduction zone only when said control signal is low and having equal polarity to said first and second transistors respectively, controlled by said control signal so that the output current is as low as possible.

A circuit for current injection control comprising:

• a first transistor having an input terminal, an output terminal and a control terminal;
• a second transistor having an input terminal connected to said output terminal of said first transistor, an output terminal and a control terminal;
• coupling means placed between said input terminal and said control terminal of said second transistor, said coupling means being active when said first and second transistors are in the cut-off zone by making the potential on the input and control terminals of the second transistor substantially equal;
• a third transistor having an input terminal connected with said input terminal of said first transistor, an output terminal and a control terminal;
• a fourth transistor having an input terminal connected to said output terminal of said third transistor, an output terminal and a control terminal;
• and
• further coupling means placed between said input terminal and said control terminal of said fourth transistor, said further coupling means being active when said third and fourth transistors are in the cut-off zone.