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19-3918; Rev 0; 3/06 ILABLE N KIT AVA EVALUATIO High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod General Description The MAX2021 low-noise, high-linearity, direct upconversion/downconversion quadrature modulator/demodulator is designed for RFID handheld and portal readers, as well as single and multicarrier 750MHz to 1200MHz GSM/EDGE, cdma2000 (R) , WCDMA, and iDEN (R) 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 performance, the MAX2021 also yields a high level of component 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 connections. As an added feature, the baseband inputs have been matched to allow for direct interfacing to the transmit DAC, thereby eliminating the need for costly I/Q 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 performance is guaranteed over the extended -40C to +85C temperature range. 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 OP1dB -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 I/Q Buffer Amplifiers DC-Coupled Input Allows Ability for Customer Offset Voltage Control Demodulator Operation: +35.2dBm Typical IIP3 +76dBm Typical IIP2 > 30dBm IP1dB 9.2dB Typical Conversion Loss 9.3dB Typical NF 0.06dB Typical I/Q Gain Imbalance 0.15 I/Q Typical Phase Imbalance MAX2021 Applications RFID Handheld and Portal Readers Single and Multicarrier WCDMA 850 Base Stations Single and Multicarrier cdmaOneTM 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. Ordering Information PART MAX2021ETX MAX2021ETX-T MAX2021ETX+ TEMP RANGE -40C to +85C -40C to +85C -40C to +85C PIN-PACKAGE PKG CODE 36 Thin QFN-EP* T3666-2 (6mm x 6mm) 36 Thin QFN-EP* T3666-2 (6mm x 6mm) 36 Thin QFN-EP* T3666-2 (6mm x 6mm) 36 Thin QFN-EP* T3666-2 (6mm x 6mm) MAX2021ETX+T -40C to +85C *EP = Exposed paddle. + = Lead free. -T = Tape-and-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. High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod MAX2021 ABSOLUTE MAXIMUM RATINGS VCC_ to GND ........................................................-0.3V to +5.5V BBI+, BBI-, BBQ+, BBQ- to GND...............-3.5V to (VCC + 0.3V) LO, RF to GND Maximum Current ......................................30mA RF Input Power ...............................................................+30dBm Baseband Differential I/Q Input Power (Note A) ............+20dBm LO Input Power...............................................................+10dBm RBIASLO1 Maximum Current .............................................10mA RBIASLO2 Maximum Current .............................................10mA RBIASLO3 Maximum Current .............................................10mA JA (without air flow) ......................................................34C/W JA (2.5m/s air flow) .........................................................28C/W JC (junction to exposed paddle) ...................................8.5C/W Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering 10s, non-lead free)...........+245C Lead Temperature (soldering 10s, lead free) ..................+260C Note A: Maximum reliable continuous power applied to the baseband differential port is +20dBm from an external 100 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 = 0V, I/Q inputs terminated into 100 differential, LO input terminated into 50, RF output terminated into 50, 0V common-mode input, R1 = 432, R2 = 619, R3 = 332, TC = -40C to +85C, unless otherwise noted. Typical values are at VCC = +5V, VBBI = VBBQ = 1.4VP-P, fIQ = 1MHz, TC = +25C, unless otherwise noted.) (Notes 1, 2) PARAMETER Supply Voltage Total Supply Current Total Power Dissipation SYMBOL VCC ITOTAL Pins 3, 13, 15, 31, 33 all connected to VCC CONDITIONS MIN 4.75 230 TYP 5.00 271 1355 MAX 5.25 315 1654 UNITS V mA mW AC ELECTRICAL CHARACTERISTICS (Modulator) (MAX2021 Typical Application Circuit, VCC = +4.75V to +5.25V, GND = 0V, I/Q differential inputs driven from a 100 DC-coupled source, 0V common-mode input, PLO = 0dBm, 750MHz fLO 1200MHz, 50 LO and RF system impedance, R1 = 432, R2 = 619, R3 = 332, TC = -40C to +85C. Typical values are at VCC = +5V, VBBI = 1.4VP-P differential, VBBQ = 1.4VP-P differential, fIQ = 1MHz, fLO = 900MHz, TC = +25C, unless otherwise noted.) (Notes 1, 2) PARAMETER BASEBAND INPUT Baseband Input Differential Impedance BB Common-Mode Input Voltage Range LO INPUT LO Input Frequency Range LO Input Drive LO Input Return Loss I/Q MIXER OUTPUTS Output IP3 Output IP2 Output P1dB Output Power Output Power Variation Over Temperature Output-Power Flatness POUT TC = -40C to +85C Sweep fBB, PRF flatness for fBB from 1MHz to 50MHz OIP3 OIP2 fBB1 = 1.8MHz, fBB2 = 1.9MHz fBB1 = 1.8MHz, fBB2 = 1.9MHz fBB = 25MHz, PLO = 0dBm fLO = 900MHz fLO = 1000MHz 21.1 22.3 57.9 16.7 0.7 -0.016 0.15 dBm dBm dBm dBm dB/C dB RF and IF terminated (Note 3) 750 -6 12 1200 +3 MHz dBm dB fIQ = 1MHz -3.5 53 0 +3.5 V SYMBOL CONDITIONS MIN TYP MAX UNITS 2 _______________________________________________________________________________________ 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 = 0V, I/Q differential inputs driven from a 100 DC-coupled source, 0V common-mode input, PLO = 0dBm, 750MHz fLO 1200MHz, 50 LO and RF system impedance, R1 = 432, R2 = 619, R3 = 332, TC = -40C to +85C. Typical values are at VCC = +5V, VBBI = 1.4VP-P differential, VBBQ = 1.4VP-P differential, fIQ = 1MHz, fLO = 900MHz, TC = +25C, unless otherwise noted.) (Notes 1, 2) PARAMETER ACLR (1st Adjacent Channel 5MHz Offset) LO Leakage Sideband Suppression Output Noise Density Output Noise Floor RF Return Loss SYMBOL CONDITIONS Single-carrier WCDMA (Note 4) No external calibration, with each baseband input terminated in 50 No external calibration, fLO = 920MHz PLO = 0dBm PLO = -3dBm 30 MIN TYP 65 -32 39.6 43.5 -174 -168 15 MAX UNITS dBc dBm dBc dBm/Hz dBm/Hz dB MAX2021 Each baseband input terminated in 50 (Note 5) POUT = 0dBm, fLO = 900MHz (Note 6) (Note 3) AC ELECTRICAL CHARACTERISTICS (Demodulator) (MAX2021 Typical Application Circuit when operated as a demodulator, VCC = +4.75V to +5.25V, GND = 0V, differential baseband outputs converted to a 50 single-ended output, PRF = PLO = 0dBm, 750MHz fLO 1200MHz, 50 LO and RF system impedance, R1 = 432, R2 = 619, R3 = 332, TC = -40C to +85C. Typical values are at VCC = +5V, TC = +25C, unless otherwise noted.) (Notes 1, 2) PARAMETER RF INPUT RF Frequency Conversion Loss Noise Figure Noise Figure Under-Blocking Input Third-Order Intercept Input Second-Order Intercept Input 1dB Compression I/Q Gain Mismatch I/Q Phase Mismatch fRF LC NF NFBLOCK IIP3 IIP2 P1dB fBB = 25MHz (Note 7) fLO = 900MHz fBLOCKER = 900MHz, PRF = 11dBm, fRF = fLO = 890MHz (Note 8) fRF1 = 925MHz, fRF2 = 926MHz, fLO = 900MHz, PRF = PLO = 0dBm, fSPUR = 24MHz fRF1 = 925MHz, fRF2 = 926MHz, fLO = 900MHz, PRF = PLO = 0dBm, fSPUR = 51MHz fIF = 50MHz, fLO = 900MHz, PLO = 0dBm fBB = 1MHz, fLO = 900MHz, PLO = 0dBm fBB = 1MHz, fLO = 900MHz PLO = 0dBm PLO = -3dBm 750 9.2 9.3 17.8 35.2 76 30 0.06 1.1 0.15 1200 MHz dB dB dB dBm dBm dBm dB degrees SYMBOL CONDITIONS MIN TYP MAX UNITS 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, PRF = -10dBm (PRF is chosen to give -65dBc ACLR). Note 5: No baseband drive input. Measured with the inputs terminated in 50. At low output levels, the output noise is thermal. Note 6: The output noise versus POUT 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(Ln/10)), determined from the modulator measurements can be used to deduce the noise figure underblocking at operating temperature (Tp in Kelvin), FBLOCK = 1 + (Lcn - 1) Tp / To + LPBLOCK / (1000kTo), where To = 290K, PBLOCK in mW, k is Boltzmann's constant = 1.381 x 10(-23) J/K, and Lcn = 10(Lc/10), Lc is the conversion loss. Noise figure under-blocking in dB is NFBLOCK = 10 x log (FBLOCK). Refer to Application Note 3632. _______________________________________________________________________________________ 3 High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod MAX2021 Typical Operating Characteristics (MAX2021 Typical Application Circuit, VCC = +4.75V to +5.25V, GND = 0V, I/Q differential inputs driven from a 100 DC-coupled source, 0V common-mode input, PLO = 0dBm, 750MHz fLO 1200MHz, 50 LO and RF system impedance, R1 = 432, R2 = 619, R3 = 332, TC = -40C to +85C. Typical values are at VCC = +5V, VBBI = 1.4VP-P differential, VBBQ = 1.4VP-P differential, fIQ = 1MHz, fLO = 900MHz, TC = +25C, unless otherwise noted.) TOTAL SUPPLY CURRENT vs. TEMPERATURE (TC) MAX2021 toc01 MODULATOR ACLR vs. OUTPUT POWER PER CARRIER MAX2021 toc02 ACLR vs. OUTPUT POWER PER CARRIER -62 -64 -66 ACLR (dB) ADJACENT CHANNEL MAX2021 toc03 300 VCC = 5.25V -60 -62 -64 -66 ACLR (dB) -60 TOTAL SUPPLY CURRENT (mA) 280 260 VCC = 5.0V 240 VCC = 4.75V 220 -68 -70 -72 -74 -76 -78 ADJACENT CHANNEL -68 -70 -72 -74 -76 ALTERNATE CHANNEL ALTERNATE CHANNEL 200 -40 -15 10 35 60 85 TEMPERATURE (C) -80 SINGLE-CARRIER WCDMA -47 -37 -27 -17 -7 -78 -80 TWO-CARRIER WCDMA -47 -37 -27 -17 -7 OUTPUT POWER PER CARRIER (dBm) OUTPUT POWER PER CARRIER (dBm) ACLR vs. OUTPUT POWER PER CARRIER -62 -64 -66 ACLR (dB) -68 -70 -72 -74 -76 -78 -80 FOUR-CARRIER WCDMA -47 -37 -27 -17 -7 ALTERNATE CHANNEL MAX2021 toc04 SIDEBAND SUPPRESSION vs. LO FREQUENCY PLO = -6dBm MAX2021 toc05 SIDEBAND SUPPRESSION vs. LO FREQUENCY MAX2021 toc06 -60 ADJACENT CHANNEL 70 SIDEBAND SUPPRESSION (dBc) 60 50 40 30 20 PLO = +3dBm 10 750 825 900 975 1050 1125 PLO = -3dBm 70 SIDEBAND SUPPRESSION (dBc) 60 50 40 30 20 10 VCC = 4.75V, 5.0V, 5.25V PLO = 0dBm 1200 750 825 900 975 1050 1125 1200 OUTPUT POWER PER CARRIER (dBm) LO FREQUENCY (MHz) LO FREQUENCY (MHz) SIDEBAND SUPPRESSION vs. LO FREQUENCY MAX2021 toc07 OUTPUT IP3 vs. LO FREQUENCY PLO = 0dBm, VCC = 5.0V 25 OUTPUT IP3 (dBm) TC = -40C TC = +25C 20 TC = +85C 15 MAX2021 toc08 OUTPUT IP3 vs. LO FREQUENCY TC = +25C VCC = 5.25V 25 OUTPUT IP3 (dBm) MAX2021 toc09 70 SIDEBAND SUPPRESSION (dBc) 60 50 40 30 20 10 750 825 900 975 1050 1125 TC = +25C TC = -40C TC = +85C 30 30 20 VCC = 5.0V VCC = 4.75V 15 10 1200 750 825 900 975 1050 1125 1200 LO FREQUENCY (MHz) LO FREQUENCY (MHz) 10 750 825 900 975 1050 1125 1200 LO FREQUENCY (MHz) 4 _______________________________________________________________________________________ High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod MAX2021 Typical Operating Characteristics (continued) (MAX2021 Typical Application Circuit, VCC = +4.75V to +5.25V, GND = 0V, I/Q differential inputs driven from a 100 DC-coupled source, 0V common-mode input, PLO = 0dBm, 750MHz fLO 1200MHz, 50 LO and RF system impedance, R1 = 432, R2 = 619, R3 = 332, TC = -40C to +85C. Typical values are at VCC = +5V, VBBI = 1.4VP-P differential, VBBQ = 1.4VP-P differential, fIQ = 1MHz, fLO = 900MHz, TC = +25C, unless otherwise noted.) MODULATOR OUTPUT IP3 vs. LO FREQUENCY MAX2021 toc10 OUTPUT IP3 vs. COMMON-MODE VOLTAGE MAX2021 toc11 OUTPUT IP3 vs. COMMON-MODE VOLTAGE fLO = 1000MHz 25 OUTPUT IP3 (dBm) 24 23 22 21 20 MAX2021 toc12 30 TC = +25C PLO = -3dBm 25 OUTPUT IP3 (dBm) PLO = +3dBm 26 fLO = 900MHz, PLO = 0dBm 25 OUTPUT IP3 (dBm) 24 23 22 21 26 20 PLO = -6dBm 15 PLO = 0dBm 10 750 825 900 975 1050 1125 1200 LO FREQUENCY (MHz) 20 -3.50 -1.75 0 1.75 3.50 COMMON-MODE VOLTAGE (V) -3.50 -1.75 0 1.75 3.50 COMMON-MODE VOLTAGE (V) OUTPUT IP2 vs. LO FREQUENCY MAX2021 toc13 OUTPUT IP2 vs. LO FREQUENCY MAX2021 toc14 OUTPUT IP2 vs. LO FREQUENCY MAX2021 toc15 80 TC = -40C 70 OUTPUT IP2 (dBm) 80 VCC = 5.25V 70 OUTPUT IP2 (dBm) 80 70 OUTPUT IP2 (dBm) PLO = +3dBm TC = +25C 60 60 VCC = 5.0V 60 PLO = -6dBm 50 TC = +85C 40 750 825 900 975 1050 1125 1200 LO FREQUENCY (MHz) 50 VCC = 4.75V 40 750 825 900 975 1050 1125 1200 LO FREQUENCY (MHz) 50 PLO = 0dBm PLO = -3dBm 40 750 825 900 975 1050 1125 1200 LO FREQUENCY (MHz) OUTPUT IP2 vs. COMMON-MODE VOLTAGE MAX2021 toc16 OUTPUT IP2 vs. COMMON-MODE VOLTAGE MAX2021 toc17 MODULATOR OUTPUT POWER vs. INPUT POWER INPUT SPLIT BETWEEN I AND Q, fIF = 25MHz, fLO = 900MHz 15 OUTPUT POWER (dBm) MAX2021 toc18 80 fLO = 900MHz 70 fLO = 1000MHz 20 75 OUTPUT IP2 (dBm) 65 OUTPUT IP2 (dBm) 70 10 60 65 5 VCC = 4.75V, 5.0V, 5.25V 0 60 55 55 -3.50 -1.75 0 1.75 3.50 COMMON-MODE VOLTAGE (V) 50 -3.50 -1.75 0 1.75 3.50 COMMON-MODE VOLTAGE (V) -5 10 13 16 19 22 25 28 INPUT POWER (dBm) _______________________________________________________________________________________ 5 High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod MAX2021 Typical Operating Characteristics (continued) (MAX2021 Typical Application Circuit, VCC = +4.75V to +5.25V, GND = 0V, I/Q differential inputs driven from a 100 DC-coupled source, 0V common-mode input, PLO = 0dBm, 750MHz fLO 1200MHz, 50 LO and RF system impedance, R1 = 432, R2 = 619, R3 = 332, TC = -40C to +85C. Typical values are at VCC = +5V, VBBI = 1.4VP-P differential, VBBQ = 1.4VP-P differential, fIQ = 1MHz, fLO = 900MHz, TC = +25C, unless otherwise noted.) MODULATOR MODULATOR OUTPUT POWER vs. INPUT POWER MAX2021 toc19 MODULATOR OUTPUT POWER vs. LO FREQUENCY MAX2021 toc20 LO LEAKAGE vs. LO FREQUENCY LO LEAKAGE NULLED AT PRF = -1dBm PRF = -40dBm PRF = +5dBm MAX2021 toc21 MAX2021 toc24 20 INPUT SPLIT BETWEEN I AND Q, fIF = 25MHz, fLO = 900MHz 15 OUTPUT POWER (dBm) 5 VBBI = VBBQ = 1.4VP-P DIFFERENTIAL TC = -40C -40 -50 LO LEAKAGE (dBm) -60 -70 -80 -90 -100 3 OUTPUT POWER (dBm) 10 1 PRF = -7dBm 5 PLO = -6dBm, -3dBm, 0dBm, +3dBm -1 TC = +85C TC = +25C 0 -3 -5 10 13 16 19 22 25 28 INPUT POWER (dBm) -5 750 825 900 975 1050 1125 1200 LO FREQUENCY (MHz) PRF = -1dBm 915 926 937 948 959 970 LO FREQUENCY (MHz) LO LEAKAGE vs. LO FREQUENCY MAX2021 toc22 LO LEAKAGE vs. LO FREQUENCY MAX2021 toc23 OUTPUT NOISE vs. OUTPUT POWER -150 -155 OUTPUT NOISE (dBm/Hz) PLO = -6dBm -160 PLO = -3dBm -165 -170 PLO = 0dBm -175 PLO = +3dBm -180 TC = +25C, fLO = 900MHz -40 -50 LO LEAKAGE (dBm) -60 -70 -80 -90 -100 PRF = -1dBm, LO LEAKAGE NULLED AT TC = +25C -40 -50 LO LEAKAGE (dBm) -60 -70 -80 -90 PRF = -1dBm, LO LEAKAGE NULLED AT PLO = 0dBm TC = -40C PLO = -6dBm PLO = -3dBm TC = +85C PLO = +3dBm TC = +25C 915 926 937 948 959 970 LO FREQUENCY (MHz) -100 915 926 PLO = 0dBm 937 948 959 970 -15 -10 -5 0 5 10 15 LO FREQUENCY (MHz) OUTPUT POWER (dBm) OUTPUT NOISE vs. OUTPUT POWER PLO = 0dBm, fLO = 900MHz MAX2021 toc25 -150 -155 OUTPUT NOISE (dBm/Hz) -160 -165 -170 -175 TC = +85C TC = -40C TC = +25C -180 -15 -10 -5 0 5 10 15 OUTPUT POWER (dBm) 6 _______________________________________________________________________________________ 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 = 0V, I/Q differential inputs driven from a 100 DC-coupled source, 0V common-mode input, PRF = 5dBm, PLO = 0dBm, 750MHz fLO 1200MHz, 50 LO and RF system impedance, R1 = 432, R2 = 619, R3 = 332, TC = -40C to +85C. Typical values are at VCC = +5V, fLO = 900MHz, TC = +25C, unless otherwise noted.) MAX2021 DEMODULATOR DEMODULATOR CONVERSION LOSS vs. LO FREQUENCY MAX2021 toc26 DEMODULATOR INPUT IP3 vs. LO FREQUENCY MAX2021 toc27 DEMODULATOR INPUT IP3 vs. LO FREQUENCY PLO = 0dBm, VCC = 5.0V TC = +25C TC = -40C 36 MAX2021 toc28 12 DEMODULATOR CONVERSION LOSS (dB) PLO = 0dBm, VCC = 5.0V TC = +25C TC = +85C 40 DEMODULATOR INPUT IP3 (dBm) PLO = 0dBm, TC = +25C VCC = 5.25V 40 DEMODULATOR INPUT IP3 (dBm) 11 38 38 10 36 9 34 VCC = 5.0V 34 8 TC = -40C 32 VCC = 4.75V 30 32 TC = +85C 30 7 750 825 900 975 1050 1125 1200 LO FREQUENCY (MHz) 750 825 900 975 1050 1125 1200 750 825 900 975 1050 1125 1200 LO FREQUENCY (MHz) LO FREQUENCY (MHz) DEMODULATOR INPUT IP2 vs. LO FREQUENCY MAX2021 toc29 DEMODULATOR PHASE IMBALANCE vs. LO FREQUENCY MAX2021 toc30 DEMODULATOR AMPLITUDE IMBALANCE vs. LO FREQUENCY DEMODULATOR AMPLITUDE IMBALANCE (dB) 0.15 0.10 0.05 0 -0.05 -0.10 -0.15 -0.20 750 825 900 975 1050 1125 LO FREQUENCY (MHz) 1200 PLO = -6dBm, -3dBm, 0dBm, +3dBm MAX2021 toc31 90 PLO = 0dBm, VCC = 5.0V DEMODULATOR INPUT IP2 (dBm) 80 TC = +25C 70 TC = +85C 60 TC = -40C 50 750 825 900 975 1050 1125 10 DEMODULATOR PHASE IMBALANCE (deg) 8 6 4 2 0 -2 -4 -6 -8 -10 750 825 PLO = +3dBm PLO = -3dBm PLO = 0dBm 0.20 PLO = -6dBm 1200 900 975 1050 1125 1200 LO FREQUENCY (MHz) LO FREQUENCY (MHz) LO PORT RETURN LOSS vs. LO FREQUENCY MAX2021 toc32 RF PORT RETURN LOSS vs. LO FREQUENCY MAX2021 toc33 IF FLATNESS vs. BASEBAND FREQUENCY PLO = 0dBm fLO = 900MHz -5 IF OUTPUT POWER (dBm) -6 -7 -8 -9 -10 -11 -12 0 10 20 30 40 50 60 70 80 fLO = 1000MHz MAX2021 toc34 0 PLO = +3dBm LO PORT RETURN LOSS (dB) +5 PLO = 0dBm +10 0 +5 RF PORT RETURN LOSS (dB) +10 +15 +20 +25 +30 +35 +40 PLO = -6dBm, -3dBm, 0dBm, +3dBm -4 +15 PLO = -6dBm, -3dBm +20 +25 750 825 900 975 1050 1125 1200 LO FREQUENCY (MHz) +45 750 845 940 1035 1130 1225 LO FREQUENCY (MHz) BASEBAND FREQUENCY (MHz) _______________________________________________________________________________________ 7 High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod MAX2021 Pin Description PIN 1, 5, 9-12, 14, 16-19, 22, 24, 27-30, 32, 34, 35, 36 2 3 4 6 7 8 13 15 20 21 23 25 26 31 33 EP NAME GND Ground FUNCTION RBIASLO3 3rd LO Amplifier Bias. Connect a 332 resistor to ground. VCCLOA LO N.C. LO Input Buffer Amplifier Supply Voltage. Bypass to GND with 33pF and 0.1F capacitors as close to the pin as possible. Local Oscillator Input. 50 input impedance. No Connection. Leave unconnected. I-Channel 1st LO Amplifier Supply Voltage. Bypass to GND with 33pF and 0.1F capacitors as close to the pin as possible. I-Channel 2nd LO Amplifier Supply Voltage. Bypass to GND with 33pF and 0.1F capacitors as close to the pin as possible. Baseband In-Phase Noninverting Port Baseband In-Phase Inverting Port RF Port Baseband Quadrature Inverting Port Baseband Quadrature Noninverting Port Q-Channel 2nd LO Amplifier Supply Voltage. Bypass to GND with 33pF and 0.1F capacitors as close to the pin as possible. Q-Channel 1st LO Amplifier Supply Voltage. Bypass to GND with 33pF and 0.1F capacitors as close to the pin as possible. Exposed Ground Paddle. The exposed paddle MUST be soldered to the ground plane using multiple vias. RBIASLO1 1st LO Input Buffer Amplifier Bias. Connect a 432 resistor to ground. RBIASLO2 2nd LO Amplifier Bias. Connect a 619 resistor to ground. VCCLOI1 VCCLOI2 BBI+ BBIRF BBQBBQ+ VCCLOQ2 VCCLOQ1 GND Detailed Description The MAX2021 is designed for upconverting differential in-phase (I) and quadrature (Q) inputs from baseband to a 750MHz to 1200MHz RF frequency range. The device can also be used as a demodulator, downconverting 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 traditional 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 mixers, in conjuction with the part's precise in-phase and quadrature channel matching, enable the device to possess excellent dynamic range, ACLR, 1dB compression 8 point, and LO and sideband suppression characteristics. These features make the MAX2021 ideal for fourcarrier WCDMA operation. LO Input Balun, LO Buffer, and Phase Splitter The MAX2021 requires a single-ended LO input, with a nominal power of 0dBm. 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 50 over the entire band of operation. The output of the LO buffer goes through a phase splitter, which generates a second LO signal that is shifted by 90 with respect to the original. The 0 and 90 LO signals drive the I 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 I and Q mixers. The amplifier boosts the level of the LO _______________________________________________________________________________________ High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod signals to compensate for any changes in LO drive levels. The two-stage LO amplifier allows a wide input power range for the LO drive. The MAX2021 can tolerate LO level swings from -6dBm to +3dBm. 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 50 load resistor to ground, and a 10mA nominal DC output current results in a 0.5V common-mode DC level into the modulator I/Q 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 carrier 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 baseband filters. The DAC's output noise floor and interpolation filter stopband attenuation are sufficiently good to ensure that the 3GPP noise floor requirement is met for large frequency offsets, 60MHz for example, with no filtering required on the RF output of the modulator. Figure 1 illustrates the ease and efficiency of interfacing the MAX2021 with a Maxim DAC, in this case the MAX5895 dual 16-bit interpolating-modulating DAC. MAX2021 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 compliance range allows for direct interface with the baseband DACs. No active buffer circuitry is required between the baseband DACs and the MAX2021 for cdma2000 and WCDMA applications. The I and Q signals directly modulate the 0 and 90 LO signals and are upconverted to the RF frequency. The outputs of the I and Q mixers are combined through a balun to produce a singled-ended RF output. Applications Information LO Input Drive The LO input of the MAX2021 is internally matched to 50, and requires a single-ended drive at a 750MHz to 1200MHz frequency range. An integrated balun converts the singled-ended input signal to a differential signal 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 I and Q baseband inputs differentially for best performance. The baseband inputs have a 53 differential input impedance. The optimum source impedance for the I and Q inputs is 100 differential. This source impedance achieves the optimal signal transfer to the I and Q inputs, and the optimum output RF impedance match. The MAX2021 can accept input power levels of up to +20dBm on the I and Q inputs. Operation with complex waveforms, such as CDMA carriers or GSM signals, utilize input power levels 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 generates an ideal total BBI MAX5895 DUAL 16-BIT INTERP DAC MAX2021 50 RF MODULATOR FREQ 50 I/Q GAIN AND OFFSET ADJUST LO 0 90 50 BBQ FREQ 50 Figure 1. MAX5895 DAC Interfaced with MAX2021 9 _______________________________________________________________________________________________________ High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod MAX2021 The MAX5895 DAC has programmable gain and differential offset controls built in. These can be used to optimize the LO leakage and sideband suppression of the MAX2021 quadrature modulator. mised by an improperly terminated I/Q IF interface. Care must be taken to match the I/Q ports to the driving DAC circuitry. Without matching, the LO's second-order (2fLO) term may leak back into the modulator's I/Q 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 addition, 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+, I-, Q+, Q- ports reduces the amount of LO leakage present at the RF port under varying temperature, LO frequency, and baseband drive conditions. See the Typical Operating Characteristics for details. Note that the resistor value is chosen to be 100 with a corner frequency 1 / (2RC) selected to adequately filter the fLO and 2fLO leakage, yet not affecting the flatness of the baseband response at the highest baseband frequency. The common-mode fLO and 2fLO signals at I+/I- and Q+/Q- effectively see the RC networks and thus become terminated in 50 (R/2). The RC network provides a path for absorbing the 2fLO and fLO leakage, while the inductor provides high impedance at fLO and 2fLO to help the diplexing process. MAX2021 MAX2021 RF Output The MAX2021 utilizes an internal passive mixer architecture that enables the device to possess an exceptionally 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 contribution from the on-chip LO buffer circuitry. As demonstrated 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 I/Q 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 I and Q voltages to the internal 50 termination. For simple sinusoidal baseband signals, a level of 89mVP-P differential on the I and the Q inputs results in a -17dBm input power level delivered to the I and Q internal 50 terminations. This results in an RF output power of -23.2dBm. RF Demodulator The MAX2021 can also be used as an RF demodulator, downconverting an RF input signal directly to baseband. 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, typically with a +35.2dBm IIP3, a P1dB of greater than +30dBm, and a 9.3dB noise figure. A wide I/Q port bandwidth allows the port to be used as an image-reject mixer for downconversion to a quadrature IF frequency. The RF and LO inputs are internally matched to 50. Thus, no matching components are required, and only DC-blocking capacitors are needed for interfacing. External Diplexer LO leakage at the RF port can be nulled to a level less than -80dBm by introducing DC offsets at the I and Q ports. However, this null at the RF port can be comproC = 6.8pF 100 I L = 40nH MAX2021 RF-MODULATOR 100 C = 6.8pF LO 0 90 100 Q L = 40nH 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 not 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, 100 C = 6.8pF Figure 2. Diplexer Network Recommended for GSM 900 Transmitter Applications 10 ______________________________________________________________________________________ High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod MAX2021 Table 1. Typical Performance Trade-Offs as a Function of Current Draw--Modulator Mode LO FREQ (MHz) RF FREQ (MHz) R1 () 420 453 800 801.8 499 549 650 420 453 900 901.8 499 549 650 420 453 1000 1001.8 499 549 650 R2 () 620 665 698 806 1000 620 665 698 806 1000 620 665 698 806 1000 R3 () 330 360 402 464 550 330 360 402 464 550 330 360 402 464 550 ICC (mA) 271 253 229 205 173 271 253 229 205 173 271 253 229 205 173 OIP3 (dBm) 19.6 21.9 18.9 15.7 13.6 20.7 21.6 20.6 19.0 14.9 22.4 22.2 19.9 17.6 14.6 LO LEAK (dBm) -32.1 -32.7 -33.7 -34.4 -34.2 -31.4 -31.6 -31.8 -31.9 -30.5 -32.8 -33.2 -33.8 -34.8 -33.9 IMAGE REJ (dBc) 23.9 34.0 30.0 23.7 23.3 43.4 42.4 42.7 40.3 25.0 39.3 39.1 43.5 40.5 36.8 OIP2 (dBm) 50.5 51.0 52.6 46.0 32.3 54.0 55.4 59.8 50.7 34.6 55.5 56.3 55.0 51.4 32.8 Note: VCC = 5V, PLO = 0dBm, TA = +25C, 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 combinations 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. 33pF and 0.1F 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 voltagesupply 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 suppression, and output power-control range. Excessive coupling between stages may degrade stability. 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 inductance. 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 to the lowerlevel 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 available upon request at www.maxim-ic.com. 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 addition, 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, in a 3 x 3 array, is suggested. Soldering the pad to ground is critical for efficient heat transfer. Use a solid ground plane wherever possible. Power-Supply Bypassing Proper voltage-supply bypassing is essential for highfrequency circuit stability. Bypass all VCC_ pins with ______________________________________________________________________________________ 11 High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod MAX2021 Table 2. Typical Performance Trade-Offs as a Function of Current Draw--Demodulator Mode LO FREQ (MHz) RF FREQ (MHz) R1 () 420 453 800 771 499 549 650 420 453 900 871 499 549 650 420 453 1000 971 499 549 650 R2 () 620 665 698 806 1000 620 665 698 806 1000 620 665 698 806 1000 R3 () 330 360 402 464 550 330 360 402 464 550 330 360 402 464 550 ICC (mA) 269 254 230 207 173 269 254 230 207 173 269 254 230 207 173 CONVERSION LOSS (dB) 9.8 9.83 9.81 9.84 9.95 9.21 9.25 9.36 9.39 9.46 9.47 9.5 9.53 9.5 9.61 IIP3 (dBm) 33.85 33.98 32.2 31.1 29.87 33.1 33.9 34.77 35.3 32 34.9 35.4 34.58 33.15 31.5 57MHz IIP2 (dBm) 62.1 62.9 66.6 66.86 65.25 68 66.87 66.7 66.6 64.64 > 77.7 > 77.5 > 76.5 > 76.5 76 Note: Used on PC board 180 combiners and off PC board quadrature combiner with VCC = 5V, PRF = -3dBm, PLO = 0dBm, TA = +25C, IF1 = 28MHz, IF2 = 29MHz. 12 ______________________________________________________________________________________ High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod Pin Configuration/Functional Diagram VCCLOQ1 VCCLOQ2 MAX2021 MAX2021 GND GND GND GND 29 GND GND 36 GND RBIASLO3 VCCLOA LO GND RBIASLO1 N.C. RBIASLO2 GND 1 2 3 4 5 6 7 8 9 10 35 34 33 32 31 30 28 27 26 25 GND BBQ+ BBQGND RF GND BBIBBI+ GND BIAS LO3 MAX2021 90 0 GND 24 23 22 21 20 19 18 BIAS LO1 BIAS LO2 11 12 13 14 15 16 17 GND GND VCCLOI1 VCCLOI2 GND GND GND THIN QFN ______________________________________________________________________________________ GND GND 13 High-Dynamic-Range, Direct Up-/Downconversion 750MHz to 1200MHz Quadrature Mod/Demod MAX2021 Typical Application Circuit VCCLOQ1 VCC C12 0.1F C13 33pF VCCLOQ2 C10 33pF C11 0.1F VCC R3 332 GND RBIASLO3 VCC C2 0.1F C1 33pF C3 82pF VCCLOA LO GND RBIASLO1 R1 432 N.C. RBIASLO2 R2 619 GND 1 2 3 4 5 6 7 8 9 GND 36 GND 35 GND 34 33 GND 32 GND 30 GND 29 28 GND 31 BIAS LO3 MAX2021 27 26 25 GND BBQ+ BBQGND Q+ QC9 8.2pF RF 90 0 24 23 RF BIAS LO1 22 21 GND BBIBBI+ GND II+ BIAS LO2 20 19 10 GND VCC 11 GND 12 GND 13 VCCLOI1 14 GND 15 VCCLOI2 16 GND 17 GND 18 GND VCC C5 0.1F C6 33pF C7 33pF C8 0.1F Table 3. Component List Referring to the Typical Application Circuit COMPONENT C1, C6, C7, C10, C13 C2, C5, C8, C11, C12 C3 C9 R1 R2 R3 VALUE 33pF 0.1F 82pF 8.2pF 432 619 332 DESCRIPTION 33pF 5%, 50V C0G ceramic capacitors (0402) 0.1F 10%, 16V X7R ceramic capacitors (0603) 82pF 5%, 50V C0G ceramic capacitor (0402) 8.2pF 0.1pF, 50V C0G ceramic capacitor (0402) 432 1% resistor (0402) 619 1% resistor (0402) 332 1% resistor (0402) Chip Information PROCESS: SiGe BiCMOS Package Information 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 (c) 2006 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc. |
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