ZABG4002 ZABG4002 document number: ds32047 rev. 2 - 2 1 of 7 www.diodes.com february 2010 ? diodes incorporated new product a product line o f diodes incorporated low power 4 stage fet lna bias controller summary the ZABG4002 is a four stage depletion mode fet bias controller intended primarily for satellite low noise block?s (lnb?s), but its also suitable for other lna applications such as those in found in pmr?s and microwave links. the ZABG4002 provides each fet with an independent protected negative gate voltage and positive drain voltage with user programmable drain current. combining an advanced ic process and packaging techniques, the ZABG4002 helps minimise power consumption, component cost and pcb area whilst enhancing overall reliability. features ? four stage fet bias controller ? operating range of 3.0v to 8.0v ? low quiescent supply current, 1.2ma typical ? fet drain voltages set at 2.0v ? fet drain current selectable from 0 to 15ma ? switchable fets for power management ? allows first and second stage fets to be run at different (optimum) drain currents ? fet drain voltages and currents held stable over temperature and vcc variations ? fets protected against overstress during power-up and power-down. ? internal negative supply generator allowing single supply operation (available for external use) ? low external component count pin assignments applications ? twin lnb?s ? quad lnb?s ? us lnb?s ? microwave links ? pmr and cellular telephone systems single universal lnb system diagram horizontal zxhf 5002 zabg 6002 zxhf 5002 zabg 4002 vertical gain stages gaas fet?s down converter if switching, gain and control horizontal zxhf 5002 zabg 6002 zxhf 5002 zabg 4002 vertical gain stages gaas fet?s down converter if switching, gain and control top view bottom view c sub g2 v cc gnd g3 d2 v cc g4 r cal1 d4 d3 d1 g1 c sub r cal2 c nb2 c nb1
ZABG4002 ZABG4002 document number: ds32047 rev. 2 - 2 2 of 7 www.diodes.com february 2010 ? diodes incorporated new product a product line o f diodes incorporated 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 ZABG4002 provides four fet bias stages, arranged in two pairs of two. resistors connected to pins rcal1 and rcal2 set the fet drain currents of each pair over the range of 0 to 15ma, allowing input fets to be biased for optimum noise and amplifier fets for optimum gain. drain voltages of all stages are set at 2.0v. the drain supplies are current limited to approximately 5% above the operating currents set by the 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 ZABG4002 includes an integrated low noise switched capacitor dc-dc converter generating a regulated output of -2.5v to allow single supply operation. to facilitate the design of e fficient low voltage 3.3v lnb systems and to maintain compatibility with higher voltage legacy designs, the ZABG4002 is capable of operating within the supply of 3.0v to 8v. these devices are unconditionally stable over the full working temperature with the fets in place, subject to the inclusion of the recommended gate and drain capacitors. these ensure rf stability and minimal injected noise. 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 t he bias circuits cannot exceed -3v. additionally each stage has its own individual current limiter. furthermore if the n egative rail experiences a fault condition, such as overload or s hort circuit, the drain supply to the fets will shut down avoiding excessive current flow. to minimise pcb space ZABG4002 is packaged in the 16 pin 3mm x 3mm qfn package. device operating temperature is -40c to 85c to suit a wide range of environmental conditions.
ZABG4002 ZABG4002 document number: ds32047 rev. 2 - 2 3 of 7 www.diodes.com february 2010 ? diodes incorporated new product a product line o f diodes incorporated maximum ratings parameter rating unit supply voltage -0.6 to +10 v supply current 80 ma power dissipation 500 mw operating temperature range -40 to +85 c storage temperature range -40 to +150 c electrical characteristics ( measured at t amb = 25c, v cc = 3.3v (note 1), r cal 1 = r cal 2 = 39k (setting i d to 10ma) unless otherwise stated) parameter conditions symbol min. typ. max. unit operating voltage range (note 1) v cc 3.0 8.0 v supply current i d1 = i d2 = i d3 = i d4 = 0 i cc 1.2 4.0 ma i d1 = i d2 = i d3 = i d4 = 10ma i cc ( l ) 42 44 ma substrate voltage i csub = 0 v csub -3.0 -2.65 -2.0 v i csub = -200ua v csub ( l ) -2.55 -2.0 v oscillator frequency f osc 150 240 600 khz gate characteristics gate (g1 to g4) current range i g -100 +500 ua voltage low i d = 12ma, i g = -10ua v g ( l ) -3.0 -2.5 -2.0 v voltage high i d = 8ma, i g = 0 v g ( h ) 0 0.7 1.0 v voltage disabled i d = 0, i g = -10ua, v rcal = 3.0v v g(dis) -3.0 -2.5 -2.0 v drain characteristics drain (d1 to d4) current range i d 0 15 ma current operating standard application circuit i d ( op ) 8 10 12 ma current disabled v d = 0, v rcal = 3.0v i d ( dis ) 10 ua voltage operating i d = 10ma v d ( op ) 1.8 2.0 2.2 v delta i d vs v cc v cc = 3.3 to 8.0v di d /dv cc 1.2 %/v delta i d vs t op t op = -40c to +85c di d /dt op 0.05 %/c delta v d vs v cc v cc = 3.3 to 8.0v dv d /dv cc 0.05 %/v delta v d vs t op t op = -40c to +85c dv d /dt op 50 ppm/c r cal (1 and 2) disable threshold v rcal ( dis ) 1.8 2.7 3.0 v input current v rcal = 3.0v i rcal ( dis ) 1.7 10 ua output noise drain voltage c gate-gnd = 10nf, c drain-gnd = 10nf v d(noise) 0.02 vpk-pk gate voltage c gate-gnd = 10nf, c drain-gnd = 10nf v g(noise) 0.005 vpk-pk notes: 1. the two vcc pins are internally connected, only one of the pins needs to be powered for the device to function. see a pplications section for further information. 2. esd sensitive, handling precautions are recommended. 3. the negative bias voltages are generated on-chip us ing an internal oscillator. two external capacitors, c nb and c sub of value 47nf are required for this purpose. 4. the package (qfn1633) exposed pad must either be connected to csub or left open circuit. 5. the characteristics are measured using two external reference resistors r cal1 and r cal2 of value 39k , wired from pins r cal1/2 to ground. resistor r cal1 sets the drain current of fets 1 and 3, resistor r cal2 sets the drain currents of fets 2 and 4. 6. noise voltage measurements are made with fets and gate and drain capacitors of value 10nf in place. noise voltages are not measured in production.
ZABG4002 ZABG4002 document number: ds32047 rev. 2 - 2 4 of 7 www.diodes.com february 2010 ? diodes incorporated new product a product line o f diodes incorporated typical characteristics ( measured at t amb = 25c, v cc = 3.3v, r cal 1 = r cal 2 = 39k (setting i d to 10ma) unless otherwise stated) ZABG4002 drain current vs r cal 0 5 10 15 10 100 1000 r cal (k) drain current (ma) ZABG4002 drain voltage vs drain current 1.8 1.9 2 2.1 2.2 0 5 10 15 drain current (ma) drain voltage (v) ZABG4002 drain drain current vs temperature 0 2 4 6 8 10 12 14 16 18 20 - 4 0- 2 00 2 04 06 08 0 temperature (c) drain current (ma) ZABG4002 drain voltage vs temperature 1.7 1.8 1.9 2 2.1 2.2 2.3 -40 -20 0 20 40 60 80 temperature (c) drain voltage (v) ZABG4002 substrate voltage vs substrate current -3 -2.8 -2.6 -2.4 -2.2 -2 0 50 100 150 200 250 substrate current (ua) substrate voltage (v)
ZABG4002 ZABG4002 document number: ds32047 rev. 2 - 2 5 of 7 www.diodes.com february 2010 ? diodes incorporated new product a product line o f diodes incorporated applications circuit applications information above is a partial applications circuit for the ZABG4002 showing all external components needed for biasing one of the four fet stages available. each bias stage is provided with a gate and dr ain pin. the drain pin provides a regulated 2.0v supply that includes a drain current monitor. the drain current taken by the external fet is compared with a user selected level, generatin g a signal that adjusts the gate voltage of the fet to obtain the required drain current. if for any reason, an attempt is made to draw more than the user set drain current from the drain pin, the drain voltage will be re duced to ensure excess current is not take n. the gate pin drivers are also current limited. the bias stages are split up into two pairs, with t he drain current of each pair set by an external r cal resistor. r cal 1 sets the drain currents of stages 1 and 3, whilst r cal 2 sets the drain currents of stages 2 and 4. this allows the optimisation of drain currents for differing tasks such as input stages where noise can be critical and later amplifier stages where gain may be more important. a graph showing the relationship between the value of r cal and i d is provided in the typical characteristics section of this datasheet. the r cal pins can also be used as logic inputs. if set to a l ogic high state (>3.0v), the associated fet bias stages are disabled, driving gate pins to -2.5v and switching drain pins open-circuit. this feature can be used as part of a power management system that turns off any unwa nted stages in a multi input receiver. the ZABG4002 includes a switched capacitor dc-dc converter that is used to generat e the negative supply required to bias depletion mode fets used in common source circuit configuration as shown above. this converter uses two external capacitors, c nb the charge transfer capacitor and c sub the output reservoir capacitor. the circuit provides a regulated -2.5v supply both for gate driver use and for external use if requ ired (for extra discrete bias stages, mixer bias, local oscillator bias etc.). the -2.5v supply is available from the c sub pin. if any bias stages are not required, their gate and drain pi ns may be left open circuit. if all bias stages associated with an r cal resistor are not required, then th is resistor may be omitted. to ease pcb layout, the pinout for the ZABG4002 includes two vcc pi ns. these pins are internally connected so only one of the pins needs to be powered for the device to function. it is proba ble that the extra pin will help avoid the need for trace cross -over components or ground plane disruption from reverse side pcb links. note that the exposed pad of t he package must be either left floating or connected to csub. jf1 vcc l* l* c* c* c1 10nf c2 10nf cnb 47nf csub 47nf rcal2 39k * stripline elements ZABG4002 rcal1 39k g2 cnb1 vcc gnd cnb2 g1 d3 vcc d1 g3 d2 d4 csub rcal2 g4 rcal1
ZABG4002 ZABG4002 document number: ds32047 rev. 2 - 2 6 of 7 www.diodes.com february 2010 ? diodes incorporated new product a product line o f diodes incorporated package outline dimensions note: controlling dimensions are in millimetres. a pproximate dimensions are provided in inches. the package appearance may vary as shown, for further details please contact your local diodes sales office. ordering information (note x) device package reel size (inches) tape width (mm) quantity (per reel) ZABG4002ja16tc qfn1633 13 8 3000 marking information qfn16 3x3 dim min max a 0.55 0.65 a1 0.00 0.05 a3 0.15 typ b 0.18 0.28 d 2.95 3.05 d2 1.40 1.60 e 0.50 bsc e 2.95 3.05 e2 1.40 1.60 l 0.35 0.45 z 0.625 typ all dimensions in mm e d e2 e b z d2 l a a3 a1 pin #1 id zabg 4002 yyww pin 1 part name date code ye ar/ we ek
ZABG4002 ZABG4002 document number: ds32047 rev. 2 - 2 7 of 7 www.diodes.com february 2010 ? diodes incorporated new product a product line o f diodes incorporated important notice diodes incorporated makes no warranty of any kind, express or implied, with regards to this document, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose (and their equivalents under the laws of any jurisdiction). diodes incorporated and its subsidiaries rese rve the right to make modifications, enhanc ements, improvements, corrections or ot her changes without further notice to this document and any product descri bed herein. diodes incorporated does not assume any liability arising out of the application or use of this document or an y product described herein; neither does di odes incorporated convey any license under its patent or trademark rights, nor the rights of others. any customer or us er of this document or products described herein in such applica tions shall assume all risks of such use and will agree to hold diodes incorporated and all the companies whose products are represented on diodes incorporated website, harmless against all damages. diodes incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthoriz ed sales channel. should customers purchase or use diodes inco rporated products for any unintended or una uthorized application, customers shall i ndemnify and hold diodes incorporated and its representativ es harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death a ssociated with such unintended or unauthorized application. products described herein may be covered by one or more united states, international or foreign patents pending. product names and markings noted herein may also be covered by one or more united states, international or foreign trademarks. life support diodes incorporated products are specifically not authorized for use as critical component s in life support devices or systems without the express written approval of the chief executive offi cer of diodes incorporated. as used herein: a. life support devices or syst ems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when proper ly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. b. a critical component is any component in a life support dev ice or system whose failure to perform can be reasonably expect ed to cause the failure of the life support device or to affect its safety or effectiveness. customers represent that they have all necessary expertise in the safety and regulatory ramifi cations of their life support dev ices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-rel ated requirements concerning the ir products and any use of diodes incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or s ystems-related information or support that may be provided by diodes incorporated. further, customers must fully indemnify diodes incorporate d and its representatives against any damages arisi ng out of the use of diodes incorporated pr oducts in such safety-critical, life suppor t devices or systems. copyright ? 2010, diodes incorporated www.diodes.com
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