A Product Line of Diodes Incorporated ZABG6002 LOW POWER 6 STAGE FET LNA AND MIXER BIAS CONTROLLER Summary The ZABG6002 is a programmable low power depletion mode FET bias and mixer controller intended primarily for satellite Low Noise Blocks (LNBs). Designed to provide system flexibility the ZABG6002 can be programmed to bias six low noise amplifier (LNA) stages or four LNA and two active mixer stages, allowing the ZABG6002 to be used in several system designs. Combining advanced IC process and packaging techniques, the ZABG6002 operates with minimal current over a wide supply voltage. The small package and reduced component count minimizes the PCB area whilst enhancing overall LNB reliability. Features Pin Assignments Six stage FET bias controller, two configurable as QFN2044 mixer stages Operating range of 3.0V to 8.0V Amplifier FET drain voltages set at 2.0V, mixer D2D2D2 D5D5D5 drain voltage set at 0.25V G2G2G2 G5G5G5 Amplifier FET drain current selectable from 0 to D3D3D3 D6D6D6 CsuCsuCsubbb 15mA, mixer current from 0 to 7.5mA G3G3G3 G6G6G6 Switchable FETs for power management RcRcRcalalalMMM RcRcRcaaalll111 FET drain voltages and currents held stable over temperature and V variations CC FETs protected against overstress during power- up and power-down. QSOP20 Internal negative supply generator allowing single supply operation (available for external use) 11 D1D1 VcVccc Low quiescent supply current, 1.6mA typical G1G1 D4D4 Low external component count D2D2 G4G4 G2G2 D5D5 Applications D3D3 G5G5 Twin LNBs G3G3 D6D6 Quad LNBs RcRcalalMM G6G6 US LNBs GndGnd RcRcalal11 Microwave links Cnb1Cnb1 RcRcalal22 PMR and Cellular telephone systems Cnb2Cnb2 CsCsubub Twin LNB System Diagrams ZXZXHFHF ZABGZABG ZABZABGG ZLNBZLNB 50025002 60026002 60026002 101022 1 of 12 May 2010 ZABG6002 Diodes Incorporated www.diodes.com Document number: DS32078 Rev. 1 - 2 VeVerrtticaicall HoriHorizontzontaall RiRightght LeLefftt GGG ddd GGG nnn 111 CnCnCnbbb111 D1D1D1 CnCnCnbbb222 VcVcVcccc CCC ububub DDD sss 444 RcRcRcaaalll222 G4G4G4 2x2 MUX2x2 MUXA Product Line of Diodes Incorporated ZABG6002 Device Description The ZABG series of devices are designed to meet the bias requirements of GaAs and HEMT FETs commonly used in satellite receiver LNBs with a minimum of external components whilst operating from a minimal voltage supply and using minimal current. The ZABG6002 has six FET bias stages that can be user programmed to provide either a two plus four arrangement of amplifier FET stages or a two plus two arrangement of amplifier FET stages along with two active mixer FET stages. Programming of the FET bias stage arrangement and the operating currents of each FET group is achieved by resistors connected to the Rcal1, Rcal2 and RcalM pins, allowing input FETs to be biased for optimum noise, amplifier FETs for optimum gain and mixer FETs (if used) for optimum conversion gain. Amplifier FETs can be operated at currents in the range 0 to 15mA and mixer FETs in the range 0.5 to 7.5mA. Drain voltages of amplifier stages are set at 2.0V and mixer stages at 0.3V. The drain supplies are current limited to approximately 5% above the operating currents set by their associated Rcal resistors. As an additional feature the Rcal pins can also be used as logic inputs to disable pairs of FETs as part of a power management scheme or simply an alternative to LNA switching. Driven to a logic high (>3.0V), the inputs disable their associated FET bias stages by switching gate feeds to -2.5V and drain feeds open circuit. Depletion mode FETs require a negative voltage bias supply when operated in grounded source circuits. The ZABG6002 includes an integrated low noise switched capacitor DC-DC converter generating a regulated output of - 2.5V to allow single supply operation. To aid efficiency and 3.3V systems the ZABG6002 has been design to used with supply rails of 3.3V to 8V It is possible to use less than the devices full complement of FET bias controls, unused drain and gate connections can be left open circuit without affecting operation of the remaining bias circuits. To protect the external FETs the circuits have been designed to ensure that, under any conditions including power up/down transients, the gate drive from the bias circuits cannot exceed -3V. Additionally each stage has its own individual current limiter. Furthermore if the negative rail experiences a fault condition, such as overload or short circuit, the drain supply to the FETs will shut down avoiding excessive current flow. The ZABG6002 is available in the 20 pin 4mm x 4mm QFN or QSOP20 package. Device operating temperature is -40C to 85C to suit a wide range of environmental conditions. 2 of 12 May 2010 ZABG6002 Diodes Incorporated www.diodes.com Document number: DS32078 Rev. 1 - 2