AT1512

www.DataSheet4U.com AT1512 Preliminary product Information FET BIAS CONTROLLER AND TONE DETECTION Features Provides bias for GaAs and HEMT FETs Drives up to 3 FETs with Dynamic FET protection Regulated negative rail generator requires only 2 external capacitors Drain current set by external resistor Choice in drain voltage Wide supply voltage range Polarisation switch for LNBs - supporting zero volt gate switching topology 22kHz tone detection for band switching Compliant with ASTRA control specifications SSOP-20 surface mount package Description The AT1512 includes bias circuits to drive up to 3 external FETs. A control input to the device selects either one of two FETs as operational using 0V gate switching topology, the third FET is permanently active. This feature is particularly used as an LNB polarisation switch. Also specific to LNB applications is the enhanced 22kHz tone detection and logic output feature which is used to enable high and low band frequency switching. The detector has been specifically designed to reject inerference such as low frequency signals and DiSEqCTM tone bursts - without the use of additional external components. Drain current setting of the AT1512 is user selectable over the range from 0 to 15mA, this is achieved with the addition of a single resistor. The series also offers the choice of FET drain voltage, the AT1512 gives 2V. These devices are unconditionally stable over the full working temperature with the FETs in place, subj...