The MC33169 is a support IC for GaAs Power Amplifier Enhanced FETs used in hand portable telephones such as GSM, PCN and DECT. This device provides negative voltages for full depletion of Enhanced MESFETs as well as a priority management system of drain switching, ensuring that the negative voltage is always present before turning "on" the Power Amplifier. Additional features include an idle mode input and a direct drive of the NChannel drain switch transistor. This product is available in two versions, 2.5 and 4.0 V. The 4.0 V version is intended for supplying RF modules for GSM and DCS1800 applications, whereas the 2.5 V version is dedicated for DECT and PHS systems.