MAXIM MAX2021 handbook
Contents
1. MODULATOR OUTPUT IP3 OUTPUT IP3 OUTPUT IP3 vs LO FREQUENCY vs COMMON MODE VOLTAGE vs COMMON MODE VOLTAGE 30 5 26 26 x E Lo 900MHz Pj o 0dBm 8 fLo 1000MHz 8 2 25 2 25 2 25 ES 24 ES 24 Ress 2 amp m m co 20 23 E 9g Ss ee p a a f 5 5 5 E S 2 o p 15 21 21 10 20 20 750 825 900 975 1050 1125 1200 3 50 175 0 175 3 50 3 50 1 75 0 1 75 3 50 LO FREQUENCY MHz COMMON MODE VOLTAGE V COMMON MODE VOLTAGE V OUTPUT IP2 vs LO FREQUENCY OUTPUT IP2 vs LO FREQUENCY OUTPUT IP2 vs LO FREQUENCY 80 e 80 z e 3 3 2 70 70 ca CO CO kJ 2 E Si Si c 60 c 60 bem a a n Lr r bes es cC ce ce 50 50 40 40 750 825 900 975 1050 1125 1200 750 825 900 975 1050 1125 1200 750 825 900 975 1050 1125 1200 LO FREQUENCY MHz LO FREQUENCY MHz LO FREQUENCY MHz OUTPUT IP2 OUTPUT IP2 MODULATOR OUTPUT POWER vs COMMON MODE VOLTAGE vs COMMON MODE VOLTAGE vs INPUT POWER 80 T 70 20 fo 900MHz 3 8 INPUT SPLIT BETWEEN AND Q 8 E 8 fic 25MHz fo 900MHz 8 75 15 E 65 z z E o z 65 3 5 a 3 E e 55 60 0 55 50 5 3 50 1 75 0 1 75 3 50 8 50 1 75 0 175 3 50 10 23 16 19 2 5 28 COMMON MODE VOLTAGE V COMMON MODE VOLTAGE V INPUT POWER dBm MAXIM 5 LCOCXVIW MAX2021 High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod Typical Operating Characteristics continued MAX2021 Typical Application Cir2. Table 3 Component List Referring to the Typical Application Circuit COMPONENT DESCRIPTION C1 C6 C7 C10 C13 33pF 5 50V COG ceramic capacitors 0402 C2 C5 C8 C11 C12 0 1uF 10 16V X7R ceramic capacitors 0603 C3 82pF 5 50V COG ceramic capacitor 0402 C9 8 2pF 0 1pF 50V COG ceramic capacitor 0402 R1 432Q 1 resistor 0402 R2 619Q 1 resistor 0402 R3 332Q 1 resistor 0402 Chip Information Package Information PROCESS SiGe BICMOS For the latest package outline information go to www maxim ic com packages Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product No circuit patent licenses are implied Maxim reserves the right to change the circuitry and specifications without notice at any time 14 Maxim Integrated Products 120 San Gabriel Drive Sunnyvale CA 94086 408 737 7600 2006 Maxim Integrated Products Printed USA MAXIM is a registered trademark of Maxim Integrated Products Inc
3. Single carrier WCDMA Note 4 LCOCXVIM o external calibration with each baseband input terminated in 50 o external calibration PLO OdBm fL o 920MHz PLo 3dBm Output Noise Density Output Noise Floor Each baseband input terminated in 50Q Note 5 Pour OdBm fj o 900MHz Note 6 RF Return Loss Note 3 AC ELECTRICAL CHARACTERISTICS Demodulator MAX2021 Typical Application Circuit when operated as a demodulator Vcc 4 75V to 5 25V GND OV differential baseband out puts converted to a 50Q single ended output PRF Pj o OdBm 750MHz lt fj o lt 1200MHz 500 LO and RF system impedance R1 432Q R2 619Q R3 3320 Tc 40 C to 85 C Typical values are at Vcc 5V Tc 25 C unless otherwise noted Notes 1 2 PARAMETER SYMBOL CONDITIONS RF INPUT RF Frequency Conversion Loss fRF Lc fgg 25MHz Note 7 oise Figure NF fio 900MHz oise Figure Under Blocking NFBLOCK fBLOCKER 900MHz PpF 11dBm fnr fL o 890MHz Note 8 nput Third Order Intercept IIP3 fRr1 925MHz fnr 926MHz fi o 900MHz PrF PLO OdBm fspUR 24MHz nput Second Order Intercept IIP2 fRr1 925MHz fnr 926MHz fi o 900MHz PrF PLO OdBm fspUR 51MHz nput 1dB Compression Q Gain Mismatch Q Phase Mismatch Diop fiF 50MHZ fi o 900MHz PLO OdBm fgg 1MHz fj o 90
4. 0MEZ PLo 0dBm fgg 1MHz PLO 0dBm fLo 900MHz PLo 3dBm Note 1 Guaranteed by design and characterization Note 2 Tc is the temperature on the exposed paddle Note 3 Parameter also applies to demodulator topology Note 4 Single carrier WCDMA with 10 5dB peak to average ratio at 0 1 complementary cumulative distribution function Pre 10dBm Pnr is chosen to give 65dBc ACLR Note 5 No baseband drive input Measured with the inputs terminated in 50Q At low output levels the output noise is thermal Note 6 The output noise versus Pour curve has the slope of LO noise Ln dBc Hz due to reciprocal mixing Note 7 Conversion loss is measured from the single ended RF input to single ended combined baseband output Note 8 The LO noise L 10 L 10 determined from the modulator measurements can be used to deduce the noise figure under blocking at operating temperature Tp in Kelvin FBLOCK 1 Len 1 Tp To LPBLock 1000kTo where To 290K PBLOCK in mW k is Boltzmann s constant 1 381 x 10 23 J K and Len 10 L6 10 c is the conversion loss Noise figure under blocking in dB is NFBLOCK 10 x log FBLOCK Refer to Application Note 3632 MAKINI MAX2021 High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod TOTAL SUPPLY CURRENT RE Tc vs TEMPERATU MAX2021 toc01 TOTAL SUPPLY CURRENT mA 40 15 1 35 60 TE
5. 19 3918 Rev 0 3 06 dh d al dd High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod General Description The MAX2021 low noise high linearity direct upcon version downconversion quadrature modulator demod ulator is designed for RFID handheld and portal readers as well as single and multicarrier 750MHz to 1200MHz GSM EDGE cdma2000 WCDMA and iDEN base station applications Direct conversion architectures are advantageous since they significantly reduce transmitter or receiver cost part count and power consumption as compared to traditional IF based double conversion systems In addition to offering excellent linearity and noise perfor mance the MAX2021 also yields a high level of compo nent integration This device includes two matched passive mixers for modulating or demodulating in phase and quadrature signals two LO mixer amplifier drivers and an LO quadrature splitter On chip baluns are also integrated to allow for single ended RF and LO connec tions As an added feature the baseband inputs have been matched to allow for direct interfacing to the trans mit DAC thereby eliminating the need for costly UO buffer amplifiers The MAX2021 operates from a single 5V supply It is available in a compact 36 pin thin QFN package 6mm x 6mm with an exposed paddle Electrical perfor mance is guaranteed over the extended 40 C to 85 C temperature range Applications RFID Handheld
6. 2mRC selected to adequately filter the fLo and 2fi o leakage yet not affecting the flatness of the baseband response at the highest baseband frequency The common mode fj o and 2fLo signals at l l and Q Q effectively see the RC networks and thus become terminated in 50Q R 2 The RC network provides a path for absorbing the 2f o and fi o leakage while the induc tor provides high impedance at fj o and 2fLo to help the diplexing process RF Demodulator The MAX2021 can also be used as an RF demodulator downconverting an RF input signal directly to base band The single ended RF input accepts signals from 750MHz to 1200MHz with power levels up to 30dBm The passive mixer architecture produces a conversion loss of typically 9 2dB The downconverter is optimized for high linearity and excellent noise performance typi cally with a 35 2dBm IIP3 a P1dB of greater than 30dBm and a 9 3dB noise figure A wide Q port bandwidth allows the port to be used as an image reject mixer for downconversion to a quadra ture IF frequency The RF and LO inputs are internally matched to 500 Thus no matching components are required and only DC blocking capacitors are needed for interfacing Power Scaling with Changes to the Bias Resistors Bias currents for the LO buffers are optimized by fine tuning resistors R1 R2 and R3 Maxim recommends using 1 tolerant resistors however standard 5 values can be used if the 1 components are no
7. A c5 Si m z z S 165 x 4 E 5 z 3 PLo 30B 170 LO 90BM 175 Pio 3dBm 180 LO FREQUENCY MHz LO FREQUENCY MHz OUTPUT NOISE vs OUTPUT POWER MAX2021 toc25 OUTPUT NOISE dBm Hz PUT POWER dBm 15 10 5 DU 0 5 10 15 PUT POWER dBm MAXIM High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod Typical Operating Characteristics MAX2021 Typical Application Circuit Vcc 4 75V to 5 25V GND OV I Q differential inputs driven from a 1000 DC coupled source OV common mode input PRF 5dBm Pi o OdBm 750MHz lt fj o lt 1200MHz 500 LO and RF system impedance R1 4320 R2 6190 R3 3320 Tc 40 C to 85 C Typical values are at Vcc 5V fj o 900MHZz Tc 25 C unless otherwise noted DEMODULATOR DEMODULATOR CONVERSION LOSS DEMODULATOR INPUT IP3 DEMODULATOR INPUT IP3 vs LO FREQUENCY vs LO FREQUENCY vs LO FREQUENCY 12 3 40 40 S Pio 0dBm Ver 5 0V 8 Pio 0dBm Tc 25 C 8 Pio 0dBm Ver 5 0V 3 ca amp amp 1 Za ES 3 e 3s To 425 C E 2 11
8. Conversion Loss 9 3dB Typical NF 0 06dB Typical UO Gain Imbalance 0 15 I Q Typical Phase Imbalance Ordering Information PKG PART CODE TEMP RANGE PIN PACKAGE 36 Thin QFN 6mm x 6m 36 Thin QFN 6mm x 6m MAX2021 ET 40 C to 85 C T3666 2 T3666 2 MAX2021 ET 40 C to 85 C MAX2021 ET MAX2021ET EP Exposed paddle Lead free T Tape ana reel package Maxim Integrated Products 1 For pricing delivery and ordering information please contact Maxim Dallas Direct at 1 888 629 4642 or visit Maxim s website at www maxim ic com LoOCXVIN MAX2021 High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod ABSOLUTE MAXIMUM RATINGS VCC W GND EE 0 3V to 5 5V RBIASLO3 Maximum Current BBI BBI BBQ BBQ to GND 3 5V to Vcc 0 3V 0JA without air flow eee LO RF to GND Maximum Current ieee 30mA OJA 2 5m s air low RE Input WOLF tes ee ete te ote b edet 30dBm OC junction to exposed poaddlel cece 8 5 C W Baseband Differential UO Input Power Note A 20dBm Junction Temperature 150 C Reflets Ve Storage Temperature Range s 65 C to 150 C RBIASLO1 Maximum Current Lead Temperature soldering 10s non lead free 245 C RBIASLO2 Maximum Current Lead Temperature soldering 10s lead free 260 C Note A Maximum reliable continuous power app
9. EECH g 38 Ver 5 25V g 38 5 Tc 85 C amp amp Tc 40 C 10 5 3 5 3 z z 8 5 5 LI 5 9 3 EEN 2 3 3 S S a amp amp E 8 a 32 eaa amp Ver 4 75V Te 85 C 7 30 30 750 825 900 975 1050 1125 1200 750 825 900 975 1050 1125 1200 750 825 900 975 1050 1125 1200 LO FREQUENCY MHz LO FREQUENCY MHz LO FREQUENCY MHz DEMODULATOR INPUT IP2 DEMODULATOR PHASE IMBALANCE DEMODULATOR AMPLITUDE IMBALANCE vs LO FREQUENCY vs LO FREQUENCY vs LO FREQUENCY 90 a 10 s 02 s Pig 0dBm Vcc 5 0V P Pio 3dBm SZ g 8 e 2 ZS us i E E T Pio 3dBm 2 S 80 Z z 01 N z 4 s Tc 25 C a Pio OdBm uw 005 P gt 2 p Ma a ui gt zZz co E c 70 0 z E c 485 C e ud z m 3dBm 0dBm 3dBm E ge x cc 0 05 a 4 L Pio 6dBm E S x 3 4 LO 60 3 0 10 a c 409 S 4 a Bg z 015 50 10 0 20 750 825 900 975 1050 1125 1200 750 825 900 975 1050 1125 1200 750 825 900 975 1050 1125 1200 LO FREQUENCY MHz LO FREQUENCY MHz LO FREQUENCY MHz LO PORT RETURN LOSS RF PORT RETURN LOSS IF FLATNESS vs LO FREQUENCY vs LO FREQUENCY vs BASEBAND FREQUENCY RAN 3 S S co co S 2 S amp a E E E E E Si 2 Pio 6dBm 3dBm 0dBm 3dBm S 9 6dBm 3dBm m uc 750 825 900 975 1050 1125 1200 750 845 940 1035 1130 1225 0 10 20 30 40 50 60 70 80 LO FREQUENCY MHz LO FREQUENCY MHz BASEBAND FREQUENCY MHz MAKUM 7 LCOCXVIW MAX2021 High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Q
10. MPERATURE C 85 ACLR vs OUTPUT POWER PER CARRIER MAX2021 toc04 ACLR dB ADJACENT CHANNEL ER 64 i a 66 Z N g 9 d 70 ALTERNATE CHANNEL a SA 72 lt 72 a E 74 Es e 76 e 78 ap L OUR CARRIER WCDMA AT 37 Di 47 4 OUTPUT POWER PER CARRIER dBm SIDEBAND SUPPRESSION vs LO FREQUENCY 10 5 g 9 Tc 85 C E E 8 S 5 E B S LLI E a z B5 es D Si S 5 3 Tp 42596 o LLI e wn 2 5 To 40 C 750 825 900 975 1050 1125 1200 LO FREQUENCY MHz LLL Typical Operating Characteristics MAX2021 Typical Application Circuit Vcc 4 75V to 5 25V GND OV UO differential inputs driven from a 1000 DC coupled source OV common mode input PL o OdBm 750MHz lt fi o 1200MHz 509 LO and RF system impedance R1 4320 R2 61990 R3 3329 Tc 40 C to 85 C Typical values are at Vcc 5V Vgp 1 4Vp p differential VBBQ 1 4Vp p differential fig 1MHz fi o 900MHZ Tc 25 C unless otherwise noted MODULATOR ACLR vs OUTPUT POWER PER CARRIER MAX2021 toc02 ENT CHANNE ATE CHAN SINGLE CARRIER WCDMA 47 37 27 17 St OUTPUT POWER P 70 ER CARRIER dBm SIDEBAND SUPPRESSION vs LO FREQUENCY 60 Pio 3dBm 50 40 ACLR dB 30 20 10 750 825 900 975 1050 1125 1200 LO FREQUE OUTPUT IP3 vs 30
11. Pio 0dBm Ver 5 0V Tc 40 4 NCY MHz LO FREQUENCY MAX2021 toc08 25 15 10 750 825 900 975 LO FREQUEI 050 1125 1200 NCY MHz SIDEBAND SUPPRESSION dBc OUTPUT IP3 dBm 30 25 ACLR vs OUTPUT POWER PER CARRIER MAX2021 toc03 ADJACENT C HANNEL ALTERNATE CHANNEL ce 37 27 2 7 UTPUT POWER P SIDEBAND SUPPRESSION ER CARRIER dBm vs LO FREQUENCY MAX2021 toc06 900 975 LO FREQUENCY MHz 050 1125 1200 OUTPUT IP3 vs LO FREQUENCY MAX2021 toc09 900 975 1050 1125 1200 LO FREQUENCY MHz MAXIM High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod Typical Operating Characteristics continued MAX2021 Typical Application Circuit Vcc 4 75V to 5 25V GND OV UO differential inputs driven from a 1000 DC coupled source OV common mode input PL o OdBm 750MHz lt fi o 1200MHz 509 LO and RF system impedance R1 4320 R2 61990 R3 332Q Tc 40 C to 85 C Typical values are at Vcc 5V Vgp 1 4Vp p differential VBBQ 1 4Vp p differential fig 1MHz fj o 900MHZ Tc 25 C unless otherwise noted
12. and Portal Readers Single and Multicarrier WCDMA 850 Base Stations Single and Multicarrier cd maOne and cdma2000 Base Stations GSM 850 GSM 900 EDGE Base Stations Predistortion Transmitters and Receivers WiMAX Transmitters and Receivers Fixed Broadband Wireless Access Military Systems Microwave Links Digital and Spread Spectrum Communication Systems Video on Demand VOD and DOCSIS Compliant Edge QAM Modulation Cable Modem Termination Systems CMTS cdma2000 is a registered trademark of Telecommunications Industry Association iDEN is a registered trademark of Motorola Inc cdmaOne is a trademark of CDMA Development Group MAXIM Features 750MHz to 1200MHz RF Frequency Range Scalable Power External Current Setting Resistors Provide Option for Operating Device in Reduced Power Reduced Performance Mode 36 Pin 6mm x 6mm TQFN Provides High Isolation in a Small Package Modulator Operation Meets 4 Carrier WCDMA 65dBc ACLR 21dBm Typical OIP3 58dBm Typical OIP2 16 7dBm Typical OP1qB 32dBm Typical LO Leakage 43 5dBc Typical Sideband Suppression 174dBm Hz Output Noise Density DC to 300MHz Baseband Input Allows a Direct Launch DAC Interface Eliminating the Need for Costly UO Buffer Amplifiers DC Coupled Input Allows Ability for Customer Offset Voltage Control Demodulator Operation 35 2dBm Typical IIP3 76dBm Typical IIP2 gt 30dBm IPigB 9 2dB Typical
13. cuit Vcc 4 75V to 5 25V GND OV UO differential inputs driven from a 1000 DC coupled source OV common mode input PL o OdBm 750MHz lt fi o lt 1200MHz 509 LO and RF system impedance R1 4320 R2 61990 R3 332Q Tc 40 C to 85 C Typical values are at Vcc 5V Vpgpj 1 4Vp p differential VBBQ 1 4Vp p differential fig 1MHz fL o 900MHZz Tc 25 C unless otherwise noted MODULATOR OUTPUT POWER vs INPUT POWER MODULATOR MODULATOR OUTPUT POWER vs LO FREQUENCY LO LEAKAGE vs LO FREQUENCY 970 MAX2021 toc24 20 e 5 g 40 INPUT SPLIT BETWEEN AND Q 3 Vee Vago 1 4Vp p 8 LO LEAKAGE NULLED AT Ppp 1dBm f fic 25MHz fio 900MHz 8 DIFFERENTIAL 3 40dBm Pr 5dBm R E 50 15 3 s E amp ZS 60 amp 10 1 70 Ge oO FA ka gt 5 5 1 z E S ap e 0 6dBm 3dBm 0dBm 3 90 Ppr 1dBm 5 5 100 10 13 16 19 22 25 28 750 825 900 975 1050 1125 1200 915 926 937 948 959 INPUT POWER dBm LO FREQUENCY MHz LO FREQUENCY MHz LO LEAKAGE vs LO FREQUENCY LO LEAKAGE vs LO FREQUENCY OUTPUT NOISE vs OUTPUT POWER 150 Pre 1dBm LO LEAKAGE NULLED AT Tc 25 C Pet 1dBm LO LEAKAGE NULLED AT P o 0dBm Tc 25 C fi o 900MHz 8 Pio 6dBm I Te 40 C E PLo 3dBm 1 155 AT 6dBm T amp amp amp 160 GE Ez R
14. d Q volt ages to the internal 50Q termination For simple sinu soidal baseband signals a level of 89mVp p differential on the and the Q inputs results in a 17dBm input power level delivered to the and Q internal 50Q termi nations This results in an RF output power of 23 2dBm External Diplexer LO leakage at the RF port can be nulled to a level less than 80dBm by introducing DC offsets at the and Q ports However this null at the RF port can be compro MAXI MAX2021 RF MODULATOR Figure 2 Diplexer Network Recommended for GSM 900 Transmitter Applications 10 mised by an improperly terminated UO IF interface Care must be taken to match the I Q ports to the driving DAC circuitry Without matching the LO s second order 2f o term may leak back into the modulator s UO input port where it can mix with the internal LO signal to produce additional LO leakage at the RF output This leakage effectively counteracts against the LO nulling In addi tion the LO signal reflected at the I Q IF port produces a residual DC term that can disturb the nulling condition As demonstrated in Figure 2 providing an RC termination on each of the I Or Q ports reduces the amount of LO leakage present at the RF port under varying temper ature LO frequency and baseband drive conditions See the Typical Operating Characteristics for details Note that the resistor value is chosen to be 100Q with a corner frequency 1
15. d of operation The output of the LO buffer goes through a phase split ter which generates a second LO signal that is shifted by 90 with respect to the original The 0 and 90 LO signals drive the and Q mixers respectively LO Driver Following the phase splitter the 0 and 90 LO signals are each amplified by a two stage amplifier to drive the and Q mixers The amplifier boosts the level of the LO MAAKLM High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod signals to compensate for any changes in LO drive lev els The two stage LO amplifier allows a wide input power range for the LO drive The MAX2021 can toler ate LO level swings from 6dBm to 3dBm I Q Modulator The MAX2021 modulator is composed of a pair of matched double balanced passive mixers and a balun The I and Q differential baseband inputs accept signals from DC to 300MHz with differential amplitudes up to 4VP P The wide input bandwidths allow operation of the MAX2021 as either a direct RF modulator or as an image reject mixer The wide common mode compli ance range allows for direct interface with the base band DACs No active buffer circuitry is required between the baseband DACs and the MAX2021 for cdma2000 and WCDMA applications The and Q signals directly modulate the 0 and 90 LO signals and are upconverted to the RF frequency The out puts of the and Q mixers are combined through a balun to produce a
16. enerates an ideal total MAKIM transmitter lineup with minimal ancillary circuit elements Such DACs include the MAX5875 series of dual DACs and the MAX5895 dual interpolating DAC These DACs have ground referenced differential current outputs Typical termination of each DAC output into a 50Q load resistor to ground and a 10mA nominal DC output cur rent results in a 0 5V common mode DC level into the modulator UO inputs The nominal signal level provided by the DACs will be in the 12dBm range for a single CDMA or WCDMA carrier reducing to 18dBm per car rier for a four carrier application The I Q input bandwidth is greater than 50MHz at 0 1dB response The direct connection of the DAC to the MAX2021 ensures the maximum signal fidelity with no performance limiting baseband amplifiers required The DAC output can be passed through a lowpass filter to remove the image frequencies from the DAC s output response The MAX5895 dual interpolating DAC can be operated at interpolation rates up to x8 This has the benefit of moving the DAC image frequencies to a very high remote frequency easing the design of the base band filters The DAC s output noise floor and interpola tion filter stopband attenuation are sufficiently good to ensure that the 3GPP noise floor requirement is met for large frequency offsets GOMHz for example with no fil tering required on the RF output of the modulator Figure 1 illustrates the ease and eff
17. iciency of interfacing the MAX2021 with a Maxim DAC in this case the MAX5895 dual 16 bit interpolating modulating DAC MAXIMA MAX2021 RF MODULATOR MAXIM MAX5895 DUAL 16 BIT INTERP DAC 50 2 AIN AND T ADJUST BBI gt Figure 1 MAX5895 DAC Interfaced with MAX2021 LEOCXVIN MAX2021 High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod The MAX5895 DAC has programmable gain and differ ential offset controls built in These can be used to opti mize the LO leakage and sideband suppression of the MAX2021 quadrature modulator RF Output The MAX2021 utilizes an internal passive mixer archi tecture that enables the device to possess an excep tionally low output noise floor With such architectures the total output noise is typically a power summation of the theoretical thermal noise KTB and the noise contri bution from the on chip LO buffer circuitry As demon strated in the Typical Operating Characteristics the MAX2021 s output noise approaches the thermal limit of 174dBm Hz for lower output power levels As the output power increases the noise level tracks the noise contribution from the LO buffer circuitry which is approximately 168dBc Hz The UO input power levels and the insertion loss of the device determine the RF output power level The input power is a function of the delivered input an
18. lied to the baseband differential port is 20dBm from an external 100Q source Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied Exposure to absolute maximum rating conditions for extended periods may affect device reliability DC ELECTRICAL CHARACTERISTICS MAX2021 Typical Application Circuit Vcc 4 75V to 5 25V GND OV I Q inputs terminated into 100Q differential LO input terminat ed into 50Q RF output terminated into 50Q OV common mode input R1 4320 R2 619Q R3 3320 Tc 40 C to 85 C unless otherwise noted Typical values are at Vcc 5V Vggi VBBQ 1 4Vp p fig 1MHz Tc 25 C unless otherwise noted Notes 1 2 PARAMETER SYMBOL CONDITIONS Supply Voltage Vcc Total Supply Current ITOTAL Pins 3 13 15 31 33 all connected to Vcc Total Power Dissipation AC ELECTRICAL CHARACTERISTICS Modulator MAX2021 Typical Application Circuit Voc 4 75V to 5 25V GND OV UO differential inputs driven from a 100Q DC coupled source OV common mode input Pj o OdBm 750MHz lt fi o 1200MHz 50Q LO and RF system impedance R1 4320 R2 6190 R3 3320 Tc 40 C to 85 C Typical values are at Vcc 5V Vpggj 1 4Vp p differential Vago 1 4Vp p differe
19. ntial fiq 1MHz fj o 900MHz Tc 25 C unless otherwise noted Notes 1 2 PARAMETER SYMBOL CONDITIONS BASEBAND INPUT Baseband Input Differential Impedance fig 1MHz BB Common Mode Input Voltage Range LO INPUT LO Input Frequency Range LO Input Drive LO Input Return Loss RF and IF terminated Note 3 UO MIXER OUTPUTS fBB1 1 8MHz fLo 900MHz faga 1 9MHz fLo 1000MHz fBB1 1 8MHz fBB 25MHz Output P1dB PLO 0dBm 16 7 dBm 0 7 dBm Output Power Output IP3 IP2 Output Power Variation Over Tc 40 C to 85 C 0 016 dB C Temperature Sweep fgg PRE flatness for fgg from 1MHz to 50MHz Output Power Flatness 0 15 dB 2 MAKII High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod AC ELECTRICAL CHARACTERISTICS Modulator continued MAX2021 Typical Application Circuit Vcc 4 75V to 5 25V GND OV UO differential inputs driven from a 1000 DC coupled source OV common mode input PLo OdBm 750MHz lt fi o lt 1200MHz 50Q LO and RF system impedance R1 4320 R2 6190 R3 332Q Tc 40 C to 85 C Typical values are at Vcc 5V Vpgp 1 4Vp p differential Vago 1 4Vp p differential fig 1MHz fi o 900MHz Tc 25 C unless otherwise noted Notes 1 2 SYMBOL CONDITIONS MAX UNITS PARAMETER ACLR 1st Adjacent Channel 5MHz Offset LO Leakage Sideband Suppression
20. o the lower level ground planes This method provides a good RF thermal conduction path for the device Solder the exposed pad on the bottom of the device package to the PC board The MAX2021 evaluation kit can be used as a reference for board layout Gerber files are avail able upon request at www maxim ic com Power Supply Bypassing Proper voltage supply bypassing is essential for high frequency circuit stability Bypass all VCC_ pins with AVLAZCLAVI 33pF and O 1yF capacitors placed as close to the pins as possible The smallest capacitor should be placed closest to the device To achieve optimum performance use good voltage supply layout techniques The MAX2021 has several RF processing stages that use the various VCC_ pins and while they have on chip decoupling off chip interaction between them may degrade gain linearity carrier sup pression and output power control range Excessive coupling between stages may degrade stability Exposed Pad RF Thermal Considerations The EP of the MAX2021 s 36 pin thin QFN EP package provides a low thermal resistance path to the die It is important that the PC board on which the IC is mounted be designed to conduct heat from this contact In addi tion the EP provides a low inductance RF ground path for the device The exposed paddle EP MUST be soldered to a ground plane on the PC board either directly or through an array of plated via holes An array of 9 vias ina 3 x 3 array is
21. s from baseband to a 750MHz to 1200MHz RF frequency range The device can also be used as a demodulator downcon verting an RF input signal directly to baseband Applications include RFID handheld and portal readers as well as single and multicarrier GSM EDGE cdma2000 WCDMA and iDEN base stations Direct conversion architectures are advantageous since they significantly reduce transmitter or receiver cost part count and power consumption as compared to tradition al IF based double conversion systems The MAX2021 integrates internal baluns an LO buffer a phase splitter two LO driver amplifiers two matched double balanced passive mixers and a wideband quadrature combiner The MAX2021 s high linearity mix ers in conjunction with the part s precise in phase and quadrature channel matching enable the device to pos sess excellent dynamic range ACLR 1dB compression 8 Exposed Ground Paddle The exposed paddle MUST be soldered to the ground plane point and LO and sideband suppression characteris tics These features make the MAX2021 ideal for four carrier WCDMA operation LO Input Balun LO Buffer and Phase Splitter The MAX2021 requires a single ended LO input with a nominal power of OdBm An internal low loss balun at the LO input converts the single ended LO signal to a differential signal at the LO buffer input In addition the internal balun matches the buffer s input impedance to 50Q over the entire ban
22. singled ended RF output Applications Information LO Input Drive The LO input of the MAX2021 is internally matched to 500 and requires a single ended drive at a 750MHz to 1200MHz frequency range An integrated balun con verts the singled ended input signal to a differential sig nal at the LO buffer differential input An external DC blocking capacitor is the only external part required at this interface The LO input power should be within the 6dBm to 3dBm range An LO input power of 3dBm is recommended for best overall peformance Baseband I Q Input Drive Drive the MAX2021 and Q baseband inputs differen tially for best performance The baseband inputs have a 53Q differential input impedance The optimum source impedance for the and Q inputs is 100Q differ ential This source impedance achieves the optimal sig nal transfer to the and Q inputs and the optimum output RF impedance match The MAX2021 can accept input power levels of up to 20dBm on the and Q inputs Operation with complex waveforms such as CDMA carriers or GSM signals utilize input power lev els that are far lower This lower power operation is made necessary by the high peak to average ratios of these complex waveforms The peak signals must be kept below the compression level of the MAX2021 The input common mode voltage should be confined to the 3 5V to 3 5V DC range The MAX2021 is designed to interface directly with Maxim high speed DACs This g
23. suggested Soldering the pad to ground is critical for efficient heat transfer Use a solid ground plane wherever possible 11 LCOCXVIW MAX2021 High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod Table 2 Typical Performance Trade Offs as a Function of Current Draw Demodulator Mode LO FREQ RF FREQ MHz MHz CONVERSION LOSS dB 57MHz IIP2 dBm 9 8 62 1 Note Used on PC board 180 combiners and off PC board quadrature combiner with Vcc 5V PRF 3dBm Pj o 0aBm TA 25 C IF1 28MHz IF2 29MHz 12 MAALM High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod GND fJ RBIASLOS 27 VCCLOA 737 RBIASLOI Ve NC 77 RBIASLO2 8 GND 9 MAKINI Pin Configuration Functional Diagram MAXIM MAX2021 LCOCXVM MAX2021 High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod Typical Application Circuit 1VCCLOQ2 R3 3820 3e S3 a mi Bo D 98 n MAXIM BIASLO3 7 C1 33pF VCCLOA uu
24. t readily available The resistor values shown in the Typical Application Circuit were chosen to provide peak performance for the entire 750MHz to 1200MHz band If desired the current can be backed off from this nominal value by choosing different values for R1 MAKLM LCOCXVIM High Dynamic Range Direct Up Downconversion 750MHz to 1200MHz Quadrature Mod Demod Table 1 Typical Performance Trade Offs as a Function of Current Draw Modulator Mode LO FREQ MHz RF FREQ MHz OIP3 dBm LO LEAK dBm IMAGE REJ dBc R3 lec Q mA 330 271 19 6 32 1 23 9 Note Vcc 5V Pj o 0OdBm TA 25 C I Q voltage levels 1 4Vp p differential R2 and R3 Tables 1 and 2 outline the performance trade offs that can be expected for various combina tions of these bias resistors As noted within the tables the performance trade offs may be more pronounced for different operating frequencies Contact the factory for additional details Layout Considerations A properly designed PC board is an essential part of any RF microwave circuit Keep RF signal lines as short as possible to reduce losses radiation and induc tance For the best performance route the ground pin traces directly to the exposed pad under the package The PC board exposed paddle MUST be connected to the ground plane of the PC board It is suggested that multiple vias be used to connect this pad t
25. uadrature Mod Demod 1 5 9 12 14 16 19 22 24 27 30 32 34 35 36 GND Ground Pin Description FUNCTION 2 RBIASLOS3 3rd LO Amplifier Bias Connect a 332Q resistor to ground 3 VCCLOA LO Input Buffer Amplifier Supply Voltage Bypass to GND with 33pF and 0 1uF capacitors as close to the pin as possible LO Local Oscillator Input 50Q input impedance RBIASLO1 1st LO Input Buffer Amplifier Bias Connect a 432Q resistor to ground N C No Connection Leave unconnected RBIASLO2 2nd LO Amplifier Bias Connect a 619Q resistor to ground VCCLOI I Channel 1st LO Amplifier Supply Voltage Bypass to GND with 33pF and O 1uF capacitors as close to the pin as possible VCCLOI2 I Channel 2nd LO Amplifier Supply Voltage Bypass to GND with 33pF and O 1uF capacitors as close to the pin as possible Baseband In Phase Noninverting Port Baseband In Phase Inverting Port RF Port Baseband Quadrature Inverting Port BBQ Baseband Quadrature Noninverting Port VCCLOQ2 Q Channel 2nd LO Amplifier Supply Voltage Bypass to GND with 33pF and O 1uF capacitors as close to the pin as possible VCCLOQ1 Q Channel 1st LO Amplifier Supply Voltage Bypass to GND with 33pF and 0 1uF capacitors as close to the pin as possible GND using multiple vias Detailed Description The MAX2021 is designed for upconverting differential in phase I and quadrature Q input
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MAXIM MAX2021 handbook