LT5571

FEATURES ■ ■ ■ ■ LT5571 620MHz – 1100MHz High Linearity Direct Quadrature Modulator DESCRIPTION The LT®5571 is a direct I/Q modulator designed for high performance wireless applications, including wireless infrastructure. It allows direct modulation of an RF signal using differential baseband I and Q signals. It supports RFID, GSM, EDGE, CDMA, CDMA2000, and other systems. It may also be configured as an image reject upconverting mixer by applying 90° phase-shifted signals to the I and Q inputs. The high impedance I/Q baseband inputs consist of voltage-to-current converters that in turn drive double-balanced mixers. The outputs of these mixers are summed and applied to an on-chip RF transformer, which converts the differential mixer signals to a 50Ω singleended output. The four balanced I and Q baseband input ports are intended for DC-coupling from a source with a common-mode voltage at about 0.5V. The LO path consists of an LO buffer with single-ended input, and precision quadrature generators that produce the LO drive for the mixers. The supply voltage range is 4.5V to 5.25V. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ■ ■ ■ ■ ■ ■ ■ Direct Conversion from Baseband to RF High Output: –4.2dB Conversion Gain High OIP3: 21.7dBm at 900MHz Low Output Noise Floor at 20MHz Offset: No RF: –159dBm/Hz POUT = 4dBm: –153.3dBm/Hz Low Carrier Leakage: –42dBm at 900MHz High Image Rejection: –53dBc at 900MHz 3-Ch CDMA2000 ACPR: –70.4dBc at 900MHz Integrated LO Buffer and LO Quadrature Phase Generator 50Ω AC-Coupled Single-Ended LO and RF Ports High Impedance DC Interface to Baseband Inputs with 0.5V Common Mode Voltage 16-Lead QFN 4mm × 4mm Package APPLICATIONS ■ ■ ■ ■ ■ RFID Interrogators GSM, CDMA, CDMA2000 Transmitters Point-to-Point Wireless Infrastructure Tx Image Reject Up-Converters for Cellular Bands Low-Noise Variable Phase-Shifter for 620MHz to 1100MHz Local Oscillator Signals TYPICAL APPLICATION Direct Conversion Transmitter Application 5V VCC I-DAC V-I I-CH 0° EN Q-CH Q-DAC BASEBAND GENERATOR VCO/SYNTHESIZER V-I –80 5571 TA01a CDMA2000 ACPR, AltCPR and Noise vs RF Output Power at 900MHz for 1 and 3 Carriers –40 LT5571 100nF ×2 RF = 620MHz TO 1100MHz ACPR, AltCPR (dBc) PA DOWNLINK TEST MODEL 64 DPCH 3-CH ACPR 3-CH AltCPR 1-CH ACPR –110 NOISE FLOOR AT 30MHz OFFSET (dBm/Hz) –50 –120 –60 –130 90° BALUN –70 1-CH NOISE 1-CH AltCPR 3-CH NOISE –90 –30 –140 –150 –160 –10 –5 0 –25 –20 –15 RF OUTPUT POWER PER CARRIER (dBm) 5571 TA01b 5571f 1 LT5571 ABSOLUTE MAXIMUM RATINGS (Note 1) PACKAGE/ORDER INFORMATION TOP VIEW BBMI BBPI GND VCC 12 GND 17 11 RF 10 GND 9 5 BBMQ 6 GND 7 BBPQ 8 VCC GND Supply Voltage .........................................................5.5V Common-Mode Level of BBPI, BBMI and BBPQ, BBMQ .......................................................0.6V Operating Ambient Temperature (Note 2) ............................................... –40°C to 85°C Storage Temperature Range................... –65°C to 125°C Voltage on any Pin Not to Exceed...................... –500mV to VCC + 500mV Note: The baseband input pins should not be left floating. 16 15 14 13 EN 1 GND 2 LO 3 GND 4 UF PACKAGE 16-LEAD (4mm × 4mm) PLASTIC QFN TJMAX = 125°C, θJA = 37°C/W EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB ORDER PART NUMBER LT5571EUF UF PART MARKING 5571 Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS SYMBOL RF Output (RF) fRF S22, ON S22, OFF NFloor RF Frequency Range RF Frequency Range RF Output Return Loss RF Output Return Loss RF Output Noise Floor PARAMETER VCC = 5V, EN = High, TA = 25°C, fLO = 900MHz, fRF = 902MHz, PLO = 0dBm. BBPI, BBMI, BBPQ, BBMQ CM input voltage = 0.5VDC, Baseband Input Frequency = 2MHz, I & Q 90° shifted (upper sideband selection). PRF(OUT) = –10dBm, unless otherwise noted. (Note 3) CONDITIONS –3dB Bandwidth –1dB Bandwidth EN = High (Note 6) EN = Low (Note 6) No Input Signal (Note 8) POUT = 4dBm (Note 9) POUT = 4dBm (Note 10) 20 • Log (VOUT, 50Ω/VIN, DIFF, I or Q) 1VP-P DIFF CW Signal, I and Q (Note 17) (Note 7) (Notes 13, 14) (Notes 13, 15) (Note 16) EN = High, PLO = 0dBm (Note 16) EN = Low, PLO = 0dBm (Note 16) MIN TYP 0.62 to 1.1 0.65 to 1.04 12.7 11.6 –159 –153.3 –152.9 –4.2 –0.2 –25.5 8.1 63.8 21.7 –53 –42 –61 MAX UNITS GHz GHz dB dB dBm/Hz dBm/Hz dBm/Hz dB dBm dB dBm dBm dBm dBc dBm dBm GV POUT G3LO vs LO OP1dB OIP2 OIP3 IR LOFT Conversion Voltage Gain Absolute Output Power 3 • LO Conversion Gain Difference Output 1dB Compression Output 2nd Order Intercept Output 3rd Order Intercept Image Rejection Carrier Leakage (LO Feedthrough) 5571f 2 LT5571 ELECTRICAL CHARACTERISTICS LO Input (LO) fLO PLO S11, ON S11, OFF NFLO GLO IIP3LO BWBB VCMBB RIN IDC, IN PLO-BB IP1dB ΔGI/Q ΔϕI/Q VCC ICC(ON) ICC(OFF) tON tOFF Enable Shutdown LO Frequency Range LO Input Power LO Input Return Loss LO Input Return Loss LO Input Referred Noise Figure LO to RF Small Signal Gain LO Input 3rd Order Intercept Baseband Bandwidth DC Common-Mode Voltage Differential Input Resistance Baseband Static Input Current Carrier Feedthrough on BB Input 1dB Compression Point I/Q Absolute Gain Imbalance I/Q Absolute Phase Imbalance Supply Voltage Supply Current Supply Current, Shutdown Mode Turn-On Time Turn-Off Time Input High Voltage Input High Current Input Low Voltage EN = High EN = 0V EN = Low to High (Note 11) EN = High to Low (Note 12) EN = High EN = 5V EN = Low 1 230 0.5 0.4 1.4 4.5 (Note 4) No Baseband Signal (Note 4) Differential Peak-to-Peak (Note 7) EN = High (Note 6) EN = Low (Note 6) at 900MHz (Note 5) at 900MHz (Note 5) at 900MHz (Note 5) –3dB Bandwidth Externally Applied (Note 4) –10 0.5 to 1.2 0 –10.9 –2.6 14.3 18.5 –4.8 400 0.5 90 –24 –42 2.9 0.013 0.24 5 97 5.25 120 100 0.6 5 GHz dBm dB dB dB dB dBm MHz V kΩ µA dBm VP-P,DIFF dB Deg V mA µA µs µs V µA V VCC = 5V, EN = High, TA = 25°C, fLO = 900MHz, fRF = 902MHz, PLO = 0dBm. BBPI, BBMI, BBPQ, BBMQ CM input voltage = 0.5VDC, Baseband Input Frequency = 2MHz, I & Q 90° shifted (upper sideband selection). PRF(OUT) = –10dBm, unless otherwise noted. (Note 3) Baseband Inputs (BBPI, BBMI, BBPQ, BBMQ) Power Supply (VCC) Enable (EN), Low = Off, High = On Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: Specifications over the –40°C to 85°C temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: Tests are performed as shown in the configuration of Figure 7. Note 4: At each of the four baseband inputs BBPI, BBMI, BBPQ and BBMQ. Note 5: V(BBPI) – V(BBMI) = 1VDC, V(BBPQ) – V(BBMQ) = 1VDC. Note 6: Maximum value within –1dB bandwidth. Note 7: An external coupling capacitor is used in the RF output line. Note 8: At 20MHz offset from the LO signal frequency. Note 9: At 20MHz offset from the CW signal frequency. Note 10: At 5MHz offset from the CW signal frequency. Note 11: RF power is within 10% of final value. Note 12: RF power is at least 30dB lower than in the ON state. Note 13: Baseband is driven by 2MHz and 2.1MHz tones. Drive level is set in such a way that the two resulting RF tones are –10dBm each. Note 14: IM2 measured at LO frequency + 4.1MHz Note 15: IM3 measured at LO frequency + 1.9MHz and LO frequency + 2.2MHz. Note 16: Amplitude average of the characterization data set without image or LO feed-through nulling (unadjusted). Note 17: The difference in conversion gain between the spurious signal at f = 3 • LO – BB versus the conversion gain at the desired signal at f = LO + BB for BB = 2MHz and LO = 900MHz. 5571f 3 LT5571 TYPICAL PERFORMANCE CHARACTERISTICS VCC = 5V, EN = High, TA = 25°C, fLO = 900MHz, fRF = 902MHz, PLO = 0dBm. BBPI, BBMI, BBPQ, BBMQ CM input voltage = 0.5VDC, Baseband Input Frequency fBB = 2MHz, I & Q 90° shifted, without image or LO feedthrough nulling. fRF = fBB + fLO (upper sideband selection). PRF(OUT) = –10dBm (–10dBm/tone for 2tone measurements), unless otherwise noted. (Note 3) RF Output Power vs LO Frequency at 1VP-P Differential Baseband Drive 2 0 SUPPLY CURRENT (mA) VOLTAGE GAIN (dB) 85°C 100 25°C 90 –40°C RF OUTPUT POWER (dBm) –2 –4 –6 –8 –10 80 4.50 –12 550 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C 650 750 850 950 1050 1150 1250 LO FREQUENCY (MHz) 5571 G02 Supply Current vs Supply Voltage 110 Voltage Gain vs LO Frequency –2 –4 –6 –8 –10 –12 –14 –16 550 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C 650 750 850 950 1050 1150 1250 LO FREQUENCY (MHz) 5558 G03 4.75 5.00 SUPPLY VOLTAGE (V) 5.25 5571 G01 Output IP3 vs LO Frequency 26 24 22 OIP3 (dBm) 20 18 16 14 12 550 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C 650 750 850 950 1050 1150 1250 LO FREQUENCY (MHz) 5571 G04 Output IP2 vs LO Frequency 75 70 65 OIP2 (dBm) 60 55 50 45 550 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C 650 750 850 950 1050 1150 1250 LO FREQUENCY (MHz) 5571 G05 Output 1dB Compression vs LO Frequency 10 8 6 4 2 0 –2 550 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C 650 750 850 950 1050 1150 1250 LO FREQUENCY (MHz) 5571 G06 fBB, 1 = 2MHz fBB, 2 = 2.1MHz fIM2 = fBB, 1 + fBB, 2 + fLO fBB, 1 = 2MHz fBB, 2 = 2.1MHz LO Feedthrough to RF Output vs LO Frequency –40 –40 2 • LO Leakage to RF Output vs 2 • LO Frequency –45 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C OP1dB (dBm) 3 • LO Leakage to RF Output vs 3 • LO Frequency 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C LO FEEDTHROUGH (dBm) 2 • LO LEAKAGE (dBm) 3 • LO LEAKAGE (dBm) –42 –50 –45 –55 –44 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C 650 750 850 950 1050 1150 1250 LO FREQUENCY (MHz) 5571 G07 –50 –60 –46 –55 –65 –48 550 –60 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2 • LO FREQUENCY (GHz) 2.5 5571 G08 –70 1.65 1.95 2.25 2.55 2.85 3.15 3.5 3.75 3 • LO FREQUENCY (GHz) 5571 G09 5571f 4 LT5571 TYPICAL PERFORMANCE CHARACTERISTICS VCC = 5V, EN = High, TA = 25°C, fLO = 900MHz, fRF = 902MHz, PLO = 0dBm. BBPI, BBMI, BBPQ, BBMQ CM input voltage = 0.5VDC, Baseband Input Frequency fBB = 2MHz, I & Q 90° shifted, without image or LO feedthrough nulling. fRF = fBB + fLO (upper sideband selection). PRF(OUT) = –10dBm (–10dBm/tone for 2tone measurements), unless otherwise noted. (Note 3) LO and RF Port Return Loss vs Frequency 0 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C S11 (dB) LO PORT, EN = LOW –10 LO PORT, EN = HIGH, PLO = 0dBm Noise Floor vs RF Frequency –157 fLO = 900MHz (FIXED) NO BASEBAND SIGNAL IMAGE REJECTION (dBc) –30 Image Rejection vs LO Frequency –158 NOISE FLOOR (dBm/Hz) –35 –159 –40 –20 RF PORT, EN = LOW RF PORT, EN = HIGH, PLO = 0dBm RF PORT, EN = HIGH, NO LO LO PORT, EN = HIGH, PLO = –10dBm –160 –161 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C 650 750 850 950 1050 1150 1250 RF FREQUENCY (MHz) 5571 G10 –45 –30 –50 –162 550 –55 550 650 750 850 950 1050 1150 1250 LO FREQUENCY (MHz) 5571 G11 –40 550 650 750 850 950 1050 1150 1250 FREQUENCY (MHz) 5571 G12 Absolute I/Q Gain Imbalance vs LO Frequency 0.3 ABSOLUTE I/Q PHASE IMBALANCE (DEG) ABSOLUTE I/Q GAIN IMBALANCE (dB) 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C 3 Absolute I/Q Phase Imbalance vs LO Frequency –2 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C –4 –6 VOLTAGE GAIN (dB) –8 –10 –12 –14 –16 –18 0 550 650 750 850 950 1050 1150 1250 LO FREQUENCY (MHz) 5571 G14 Voltage Gain vs LO Power 0.2 2 0.1 1 0 550 650 750 850 950 1050 1150 1250 LO FREQUENCY (MHz) 5571 G13 –20 –20 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C –16 –12 –8 –4 0 4 LO INPUT POWER (dBm) 8 5571 G15 Output IP3 vs LO Power 24 22 LO FEEDTHROUGH (dBm) 20 OIP3 (dBm) 18 16 14 12 10 –20 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C fBB, 1 = 2MHz fBB, 2 = 2.1MHz 4 –16 –12 –8 –4 0 LO INPUT POWER (dBm) 8 5571 G16 LO Feedthrough vs LO Power –38 –40 –42 –44 –46 –48 –50 –20 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C –16 –12 –8 –4 0 4 LO INPUT POWER (dBm) 8 5571 G17 Image Rejection vs LO Power –35 –40 IMAGE REJECTION (dBc) –45 –50 –55 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C –16 –12 –8 –4 0 4 LO INPUT POWER (dBm) 8 5571 G18 –60 –20 5571f 5 LT5571 TYPICAL PERFORMANCE CHARACTERISTICS RF CW Output Power, HD2 and HD3 vs CW Baseband Voltage and Temperature 0 –10 –20 HD2, HD3 (dBc) –30 –40 –50 –60 –70 –80 0 1 HD2 HD3 RF 20 10 RF CW OUTPUT POWER (dBm) 0 25°C –10 85°C –40°C –20 –30 –10 RF –20 –30 HD2, HD3 (dBc) HD3 –40 –50 –60 –70 –80 0 1 0 RF CW OUTPUT POWER (dBm) 5V –10 5.5V 4.5V –20 –30 LO FEEDTHROUGH (dBm) VCC = 5V, EN = High, TA = 25°C, fLO = 900MHz, fRF = 902MHz, PLO = 0dBm. BBPI, BBMI, BBPQ, BBMQ CM input voltage = 0.5VDC, Baseband Input Frequency fBB = 2MHz, I & Q 90° shifted, without image or LO feedthrough nulling. fRF = fBB + fLO (upper sideband selection). PRF(OUT) = –10dBm (–10dBm/tone for 2tone measurements), unless otherwise noted. (Note 3) RF CW Output Power, HD2 and HD3 vs CW Baseband Voltage and Supply Voltage 10 –30 LO Feedthrough to RF Output vs CW Baseband Voltage 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C –35 HD2 –40 HD2 = MAX POWER AT fLO + 2 • fBB OR fLO – 2 • fBB –50 HD3 = MAX POWER AT fLO + 3 • fBB OR fLO – 3 • fBB –60 4 5 2 3 5571 G19 –40 HD2 = MAX POWER AT fLO + 2 • fBB OR fLO – 2 • fBB –50 HD3 = MAX POWER AT fLO + 3 • fBB OR fLO – 3 • fBB –60 2 3 4 5 5571 G20 –40 –45 0 1 2 3 4 5 I AND Q BASEBAND VOLTAGE (VP-P, DIFF) 5571 G21 I AND Q BASEBAND VOLTAGE (VP-P, DIFF) I AND Q BASEBAND VOLTAGE (VP-P, DIFF) Image Rejection vs CW Baseband Voltage –46 –48 IMAGE REJECTION (dBc) –50 –52 –54 –56 –58 0 5 1 2 3 4 I AND Q BASEBAND VOLTAGE (VP-P,DIFF) 5571 G22 RF Two-Tone Power (Each Tone), IM2 and IM3 vs Baseband Voltage and Temperature 10 0 PTONE (dBm), IM2, IM3 (dBc) –10 –20 IM2 = POWER AT fLO + 4.1MHz –30 IM3 = MAX POWER AT fLO + 1.9MHz –40 OR fLO + 2.2MHz –50 –60 –70 –80 fBBI = 2MHz, 2.1MHz, 0° fBBQ = 2MHz, 2.1MHz, 90° IM3 25°C 85°C –40°C 10 0 PTONE (dBm), IM2, IM3 (dBc) RF –10 RF Two-Tone Power (Each Tone), IM2 and IM3 vs Baseband Voltage and Supply Voltage 5V 5.5V 4.5V 5V, –40°C 5V, 25°C 5V, 85°C 4.5V, 25°C 5.5V, 25°C RF IM3 IM2 –20 IM2 = POWER AT fLO + 4.1MHz –30 IM3 = MAX POWER AT fLO + 1.9MHz –40 OR fLO + 2.2MHz –50 –60 –70 –80 IM2 fBBI = 2MHz, 2.1MHz, 0° fBBQ = 2MHz, 2.1MHz, 90° 1 10 0.1 I AND Q BASEBAND VOLTAGE (VP-P,DIFF, EACH TONE) 5571 G23 1 10 0.1 I AND Q BASEBAND VOLTAGE (VP-P,DIFF, EACH TONE) 5571 G24 Voltage Gain Distribution 25 –40°C 25°C 85°C VBB = 400mVP-P 25 Noise Floor Distribution (no RF) –40°C 25°C 85°C PERCENTAGE (%) 20 LO Leakage Distribution –40°C 25°C 85°C VBB = 400mVP-P 20 PERCENTAGE (%) 20 PERCENTAGE (%) 15 15 10 10 10 5 5 0 –6.5 –6 –5.5 –5 –4.5 –4 –3.5 –3 –2.5 –2 5571 G25 GAIN (dB) 0 –159.9 –159.6 –159.3 –159.0 NOISE FLOOR (dBm/Hz) –158.7 5571 G26 0