ZNBG4000 ZNBG4001ZNBG4000 FET BIAS CONTROLLER ZNBG6000 ZNBG6001 ISSUE 2 - JUNE 1998 DEVICE DESCRIPTION The ZNBG series of devices are designed to These devices are unconditionally stable meet the bias requirements of GaAs and over the full working temperature with the HEMT FETs commonly used in satellite FETs in place, subject to the inclusion of the receiver LNBs, PMR, cellular telephones etc. recommended gate and drain capacitors. with a minimum of external components. These ensure RF stability and minimal injected noise. With the addition of two capacitors and resistors the devices provide drain voltage It is possible to use less than the devices full and current control for a number of external complement of FET bias controls, unused grounded source FETs, generating the drain and gate connections can be left open regulated negative rail required for FET gate circuit without affecting operation of the biasing whilst operating from a single remaining bias circuits. supply. This negative bias, at -3 volts, can In order to protect the external FETs the also be used to supply other external circuits have been designed to ensure that, circuits. under any conditions including power The ZNBG4000/1 and ZNBG6000/1 contain up/down transients, the gate drive from the four and six bias stages respectively. In bias circuits cannot exceed the range -3.5V setting drain current the ZNBG4000/1 two to 0.7V. Furthermore if the negative rail resistors allows individual FET pair control experiences a fault condition, such as to different levels, the ZNBG6000/1 two overload or short circuit, the drain supply to resistors split control between two and four the FETs will shut down avoiding excessive FETs. This allows the operating current of current flow. input FETs to be adjusted to minimise noise, The ZNBG4000/1 and ZNBG6000/1 are whilst the following FET stages can available in QSOP16 and 20 pin packages separately be adjusted for maximum gain. respectively for the minimum in devices size. The series also offers the choice of drain Device operating temperature is -40 to 70C voltage to be set for the FETs, the to suit a wide range of environmental ZNBG4000/6000 gives 2.2 volts drain whilst conditions. the ZNBG4001/6001 gives 2 volts. FEATURES APPLICATIONS Provides bias for GaAs and HEMT FETs Satellite receiver LNBs Drives up to four or six FETs Private mobile radio (PMR) Dynamic FET protection Cellular telephones Drain current set by external resistor Regulated negative rail generator requires only 2 external capacitors Choice in drain voltage Wide supply voltage range QSOP surface mount package 4-137ZNBG40ZNBG4000 ZNBG400100 ZNBG6000 ZNBG6001 ABSOLUTE MAXIMUM RATINGS Supply Voltage -0.6V to 15V Power Dissipation (T = = 25C) amb Supply Current 100mA QSOP16 500mW Drain Current (per FET) 0 to 15mA QSOP20 650mW (set by R and R ) CAL1 CAL2 Output Current 100mA Operating Temperature -40 to 70C Storage Temperature -50 to 85C ELECTRICAL CHARACTERISTICS TEST CONDITIONS (Unless otherwise stated): T = = 25C,V =5V,I =10mA (R =33k R =33k) amb CC D CAL1 CAL2 SYMBOL PARAMETER CONDITIONS LIMITS UNITS Min Typ Max V Supply Voltage 5 12 V CC I Supply Current I to I =0 10 mA CC D1 D4 ZNBG4000/1 I to I =10mA 50 mA D1 D4 I Supply Current ID1 to I =0 15 mA CC D6 ZNBG6000/1 I to I =10mA 75 mA D1 D6 V Substrate Voltage I = 0 -3.5 -3 -2 V SUB SUB (Internally generated) I = -200A -2 V SUB Output Noise E Drain Voltage C =4.7nF, C =10nF 0.02 Vpkpk ND G D E Gate Voltage C =4.7nF, C =10nF 0.005 Vpkpk NG G D f Oscillator Freq. 200 350 800 kHz O DRAIN CHARACTERISTICS I Current 8 10 12 mA D Current Change I with V V =5 to 12V 0.02 %/V DV CC CC I with T T =-40 to +70C 0.05 %/C j j DT V Voltage D ZNBG4000, ZNGB6000 2 2.2 2.4 V ZNBG4001, ZNBG6001 1.8 2 2.2 V Voltage Change V with V V = 5 to 12V 0.5 %/V DV CC CC V with T T = -40 to +70C 50 ppm j j DT 4-138