AMMC-6232 Application and Usage
Biasing and Operation
To VDD DC supply
TheꢀAMMC-6232ꢀisꢀnormallyꢀbiasedꢀwithꢀaꢀpositiveꢀdrainꢀ
supplyꢀ connectedꢀ toꢀ theꢀ VD1ꢀ andꢀ VD2ꢀ padsꢀ throughꢀ
bypassꢀ capacitorꢀ asꢀ shownꢀ inꢀ Figuresꢀ 15ꢀ andꢀ 16.ꢀ Theꢀ
recommendedꢀdrainꢀvoltageꢀandꢀgateꢀvoltageꢀforꢀgeneralꢀ
usageꢀ isꢀ 4Vꢀ andꢀ -0.95Vꢀ respectively.ꢀWithꢀVdd=4V,ꢀVg=-
0.95V,ꢀtheꢀcorrespondingꢀdrainꢀcurrentꢀisꢀapproximatelyꢀ
135mA.ꢀ Itꢀ isꢀ importantꢀ toꢀ haveꢀ atꢀ leastꢀ 0.1upFꢀ bypassꢀ
capacitorꢀ andꢀ theꢀ capacitorꢀ shouldꢀ beꢀ placedꢀ asꢀ closeꢀ
toꢀ theꢀ componentꢀ asꢀ possible.ꢀ Aspectsꢀ ofꢀ theꢀ amplifierꢀ
performanceꢀmayꢀbeꢀimprovedꢀoverꢀaꢀnarrowerꢀbandwidthꢀ
byꢀ applicationꢀ ofꢀ additionalꢀ conjugate,ꢀ linearity,ꢀ orꢀ lowꢀ
noiseꢀ(Topt)ꢀmatching.
0.1 uF Capacitor
VD1
VD2
RF OUTPUT
RF INPUT
AMMC-6232
To VGate DC supply
Afterꢀ adjustingꢀ theꢀ gateꢀ biasꢀ toꢀ obtainꢀ 135mAꢀ atꢀ Vddꢀ
=ꢀ 4V,ꢀ theꢀ AMMC-6232ꢀ canꢀ beꢀ safelyꢀ biasedꢀ atꢀ Vdd=ꢀ
3Vꢀ orꢀ 5Vꢀ (whileꢀ fixingꢀ theꢀ gateꢀ bias)ꢀ asꢀ desired.ꢀ Atꢀ 4V,ꢀ
theꢀ performanceꢀ isꢀ anꢀ optimalꢀ compromiseꢀ betweenꢀ
powerꢀconsumption,ꢀgainꢀandꢀpower/linearity.ꢀItꢀisꢀbothꢀ
applicableꢀtoꢀbeꢀusedꢀasꢀaꢀlowꢀnoiseꢀblockꢀorꢀdriver.ꢀAtꢀ3V,ꢀ
theꢀamplifierꢀisꢀidealꢀasꢀaꢀfrontꢀendꢀlowꢀnoiseꢀblockꢀwhereꢀ
linearityꢀ isꢀ notꢀ highlyꢀ required.ꢀ Atꢀ 5V,ꢀ theꢀ amplifierꢀ canꢀ
provideꢀ~ꢀ2dBꢀmoreꢀoutputꢀpowerꢀforꢀLOꢀorꢀtransmitterꢀ
driverꢀapplicationsꢀwhereꢀhighꢀoutputꢀpowerꢀandꢀlinearityꢀ
areꢀoftenꢀrequired.
Figure 19. Gate Bias Combined Together
To VDD DC supply
0.1 uF Capacitor
VD1
VD2
RF OUTPUT
RF INPUT
AMMC-6232
Theꢀ twoꢀ gateꢀ voltagesꢀ canꢀ beꢀ combinedꢀ asꢀ shownꢀ inꢀ
Figureꢀ15ꢀorꢀseparatedꢀasꢀinꢀFigureꢀ16.ꢀCombiningꢀtheꢀtwoꢀ
gateꢀ voltagesꢀ simplifiesꢀ theꢀ usageꢀ whereasꢀ separatingꢀ
themꢀprovidesꢀflexibilityꢀtoꢀoverallꢀbiasingꢀscheme.
Gold Plated Shim (Optional)
To VG1 DC supply
To VG2 DC supply
Inꢀbothꢀcases,ꢀbondingꢀwiresꢀatꢀtheꢀinputꢀandꢀoutputꢀinꢀ
theꢀrangeꢀofꢀ0.15nHꢀwouldꢀlikelyꢀimproveꢀtheꢀoverallꢀNoiseꢀ
Figureꢀandꢀinput,ꢀoutputꢀmatchꢀatꢀmostꢀfrequencies.ꢀ
Figure 20. Separated Gate Bias
Noꢀgroundꢀwiresꢀareꢀneededꢀbecauseꢀgroundꢀconnectionꢀ
isꢀmadeꢀwithꢀplatedꢀthrough-holesꢀtoꢀtheꢀbacksideꢀofꢀtheꢀ
substrate.ꢀ
Figure 21. Simplified High Linearity LNA Schematic
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