DEMO MANUAL DC2035A LTC5551 300MHz to 3.5GHz Ultra-High Dynamic Range Downconverting Mixer DESCRIPTION Demonstration circuit 2035A features LTC®5551, which is a 300MHz to 3.5GHz ultra high dynamic range down converting mixer. Demo circuit 2035A is optimized for RF input frequency range 1.1GHz to 2.7GHz. IF output port is optimized for frequency range 116MHz to 250MHz. RF input can be matched with few external component for a wide range of frequencies. IF output port can be matched externally up to 500MHz. A typical application with low side LO injection provides the best performance for RF input frequency range 1.1GHz to 2.7GHz. LTC5551 is optimized for 3.3V operation. A low power mode is available and is activated by pulling the ISEL pin high. This reduces the power consumption by 1/3, however reduces the IIP3 to approximately 29dBm. Design files for this circuit board are available at http://www.linear.com/demo/DC2035A L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. PERFORMANCE SUMMARY Specifications are at VCC = 3.3V, EN = 3.3V, TC = 25°C, ISEL = LOW, PLO = 0dBm, PRF = 0dBm (∆f = 2MHz, 0dBm/tone for two-tone IIP3 tests), unless otherwise noted. Test circuit shown in Schematic Diagram. PARAMETER CONDITION VCC Supply Voltage TYP 2.5 to 3.6 UNITS V VCC Supply Current EN = High, with LO Signal Applied EN = High, ISIL = HIGH, with LO Signal Applied 204 142 mA mA Shutdown Current EN = Low <100 µA EN Voltage Low, Chip Disabled HIGH, Chip Enabled <0.3 >1.2 V V EN Input Current VEN = 0V to 3.3V –30 to 100 µA RF Input Frequency Range LO Signal Applied, with External Match 1.1 to 2.7 GHz RF Input Return Loss LO Signal Applied IF Output Frequency Range LO Signal Applied, with External Match >10 IF Output Return Loss LO Signal Applied >10 dB LO Frequency Range With External Match 1.0 to 3.5 GHz LO Input Return Loss With External Match >10 dB LO Input Power LO = 1000MHz to 3500MHz,with External LO Match –6 to 6 dBm LO to RF leakage LO = 1000MHz to 3500MHz, with External LO Match ≤25 dBm LO to IF leakage LO = 1000MHz to 3500MHz,with External LO Match ≤21 dBm RF to LO Isolation RF = 1.1GHz to 2.7GHz, with External Match >55 dB RF to IF Isolation RF = 1.1GHz to 2.7GHz, with External Match >23 dB 2.5 2.5 2.4 1.7 dB dB dB dB 116 to 250 dB MHz 1.1GHz to 2.7GHz Downmixer Application: IF = 153MHz, ISEL = Low, Unless Otherwise Noted. Power Conversion Gain RF = 1100MHz, Low Side LO RF = 1500MHz, Low Side LO RF = 1950MHz, Low Side LO RF = 2700MHz, Low Side LO dc2035af 1 DEMO MANUAL DC2035A PERFORMANCE SUMMARY Specifications are at VCC = 3.3V, EN = 3.3V, TC = 25°C, ISEL = LOW, PLO = 0dBm, PRF = 0dBm (∆f = 2MHz, 0dBm/tone for two-tone IIP3 tests), unless otherwise noted. Test circuit shown in Schematic Diagram. PARAMETER CONDITION TYP UNITS 2-Tone 3rd Order Intercept RF = 1100MHz, Low Side LO RF = 1500MHz, Low Side LO RF = 1950MHz, Low Side LO RF = 2700MHz, Low Side LO 36.0 36.0 35.5 38.1 dBm dBm dBm dBm 2-Tone Input 2nd Order Intercept (∆f = 154MHz = fIM2) RF = 1950MHz (2027MHz/1873MHz), LO = 1797MHz 58.4 dBm SSB Noise Figure RF = 1950MHz, Low Side LO 9.7 dB Input 1dB Compression RF = 1950MHz, Low Side LO 18 dBm Power Conversion Gain RF = 1950MHz, Low Side LO 2.4 dB Input 3rd Order Intercept RF = 1950MHz, Low Side LO 29.3 dBm SSB Noise Figure RF = 1950MHz, Low Side LO 8.3 dB Input 1dB Compression RF = 1950MHz, Low Side LO 16.7 dBm Low Power Mode, IF = 153MHz, ISEL = High DETAILED DESCRIPTION Absolute Maximum Ratings Note: Stresses beyond absolute maximum ratings may cause permanent damage to the device. Exposure to any absolute maximum rating conditions for extended periods may affect the device reliability and lifetime. Supply Voltage (VCC, IF+, IF –)......................................4V Enable Input Voltage (EN).................–0.3V to VCC + 0.3V Power Select Voltage (ISEL).............–0.3V to VCC + 0.3V LO Input Power (0.2GHz to 3.5GHz).................... +10dBm LO Input DC Voltage................................................ ±0.1V RF Input Power (0.3GHz to 3.5GHz)....................+20dBm RF Input DC Voltage................................................ ±0.1V Temp Diode Continuous DC input Current...............10mA Temp Diode Input Voltage.......................................... ±1V IFBIAS Voltage..........................................................2.5V Operating Temperature Range (TC)......... –40°C to 105°C Supply Voltage Ramping Fast ramping of the supply voltage can cause current glitch in the internal ESD protection circuits. Depending on supply leads inductance, this could result in a supply voltage transient that exceeds the maximum rating. A supply voltage ramp time of greater than 1ms is recommended. Supply leads used to power the demo board should be as short as possible to minimize the lead inductance and resistance. During power-up, connect the power leads to the demo board before turning on the power supply. Supply voltage should be ramped up slowly to 3.3V to avoid any overshoot transients which may damage the IC. Enable Feature To enable the chip, EN voltage must be greater than 1.2V. However, EN voltage must not exceed VCC by more than 0.3V to avoid permanent damage to the chip. When EN is left floating, the voltage will be pulled low by the internal pull-down resistor, and the chip will be disabled. Low Power Mode The LTC5551 can be set to low power mode using a digital voltage applied to ISEL. This allows flexibility to choose a reduced current of operation when lower RF performance is acceptable. When ISEL is set to low (<0.3V), the mixer operate at nominal DC current. When ISEL is set to high (>1.2V), DC current consumption is reduced resulting in lower RF performance. When ISEL is left floating, ISEL is pulled down to low voltage by the internal pull down resistor. dc2035af 2 DEMO MANUAL DC2035A DETAILED DESCRIPTION Temperature Diode LO Input The LTC5551 provides an on-chip diode connected to TEMP on the demo board. TEMP is connected to the anode of the internal ESD diode. The junction temperature can be measured by injecting a 10µA current into TEMP pin. The voltage vs temperature coefficient of the diode is about –1.72mV/°C with 10µA current injected into the TEMP pin. The LO input on DC2035A is externally matched from 1000MHz to 3500MHz with series 3.9pF capacitor. Matching below 1000MHz can be accomplished by adding a shunt component at C3, see Table 1. A series DC blocking capacitor must be used to avoid damage to the integrated transformer if DC voltage is present at the LO input. RF Input LO Input Return Loss 0 The RF input of DC2035A is externally matched from 1100MHz to 2700MHz, with return loss greater than 10dB. However, the RF input match can be shifted down to 300MHz, or up to 3500MHz by replacing the external matching components, see Table 1. A series DC blocking capacitor must be used if DC voltage is present at the RF input to avoid damage to the internal input transformer. RETURN LOSS (dB) 5 10 15 20 RF Input Return Loss (with LO Signal Applied) 0 25 5 0 0.5 1.0 1.5 2.0 2.5 3.0 LO FREQUENCY (GHz) 3.5 4.0 dc2035a LO RETURN LOSS (dB) 10 IF Output 15 IF output port can be matched for IF frequencies as low as 5MHz, and as high as 500MHz. Standard demo board is matched for center frequency 153MHz. Other frequencies can be matched by changing the values of L1, and L2. See table below for inductor values for other IF frequencies. 20 25 30 35 40 1 0 2 3 RF FREQUENCY (GHz) 4 dc2035a RF Table 1. Matching Values at Other Frequencies (See Schematic Diagram) APPLICATION RF MATCH LO MATCH IF TRANSFORMER RF (MHz) LO X1 C1 X2 C2 C3 T1 VENDOR 300 to 650 HS 15nH 15pF 15pF 15pF 8.2pF TC4-1W-7ALN+ Mini-Circuit 500 to 1100 HS 13nH 6.8pF 4.7pF 8.2pF 2.2pF WBC4-6TLB Coilcraft 1100 to 2700 LS, HS 7.5nH 2.2pF – 3.9pF – TC4-1W-7ALN+ Mini-Circuit 2300 to 3500 LS, HS 1.2pF 22pF 2.2nH 3.9pF – TC4-1W-7ALN+ Mini-Circuit dc2035af 3 DEMO MANUAL DC2035A DETAILED DESCRIPTION IF Return Loss (with LO Signal Applied) 0 L1,L2 vs IF Frequencies RETURN LOSS (dB) 2 4 6 8 10 12 Table 2. Inductor Matching Values vs IF Frequencies 0 100 300 200 400 IF FREQUENCY (MHz) IF (MHz) L1, L2 (nH) COMMENTS 120 820 Coilcfraft 0603 LS 153 470 Coilcfraft 0603 LS 240 180 Coilcfraft 0603 LS 305 120 Coilcfraft 0603 LS 380 56 Coilcfraft 0603 LS 456 33 Coilcfraft 0603 LS 500 dc2035a IF QUICK START PROCEDURE Demonstration circuit 2035A is easy to set up to evaluate the performance of the LTC5551. Refer to Figures 1 to 3 for proper equipment connections and follow the procedures below: Note: Care should be taken to never exceed absolute maximum input ratings. Make all connections with RF and DC power off. Return Loss Measurements 1.Configure the network analyzer for return loss measurement, set appropriate frequency range, and set the test signal to 0dBm. 2.Calibrate the network analyzer. 3.Connect all test equipment as shown in Figure 1 with the signal generator and the DC power supply turned off. 4.Ramp up VCC supply voltage to 3.3V, and verify that the current consumption is approximately 204mA with LO signal applied and ISEL set to Low. The correct supply voltage should be confirmed, measured at the demo board to account for the voltage drop across supply leads. 5.Set the LO source to provide a 0dBm, CW signal to the demo board LO input port at appropriate LO frequency. 6.With the LO signal applied, and the unused demo board ports terminated in 50Ω, measure return losses of the RF input and IF output ports. 7.Terminate the RF input and the IF output ports in 50Ω. Measure return loss of the LO input port. RF Performance Measurements 1.Connect all test equipment as shown in Figure 2 with the signal generators and the DC power supply turned off. 2.Ramp up the VCC supply voltage to 3.3V, and verify that the current consumption is approximately 204mA with LO signal applied. The supply voltage should be confirmed at the demo board VCC and GND terminals to account for the voltage drop across wire leads. 3.Set the LO source signal generator to provide 0dBm, CW signal to the demo board LO input port at the appropriate LO frequency. 4.Set the RF sources, to provide the two tone inputs at 0dBm per tone, CW signal 2MHz apart to the demo board RF input port at the appropriate RF frequency. 5.Measure the resulting IF output on the spectrum analyzer: dc2035af 4 DEMO MANUAL DC2035A QUICK START PROCEDURE a. Measure The wanted two-tone IF output signals are located at: Low Side LO: 6.Turn off one of the RF signal generators, and measure conversion gain, RF to IF isolation, LO to IF leakage, and input 1dB compression point. fIF1 = fRF1 – fLO, Noise Figure Measurements fIF2 = fRF2 – fLO 1.Configure and calibrate the noise figure meter for mixer measurements. High Side LO: 2.Connect all test equipment as shown in Figure 3 with signal generator and DC power supply turned off. fIF1 = fLO – fRF1, fIF2 = fLO – fRF2 b.The 3rd order intermodulation products which are closest to the wanted IF signals are used to calculate the input 3rd order intercept, where ∆IF = fIF2 – fIF1: fIM3,1 = fIF1 – ∆IF fIM3,2 = fIF2 + ∆IF b.Calculate the input 3rd order intercept: IIP3 = (∆IM3)/2 + PRF 3.Increase VCC supply voltage to 3.3V, and verify that the current consumption is approximately 204mA with LO signal applied. The supply voltage should be confirmed at the demo board VCC and GND terminals to account for voltage drop across supply leads. 4.Set LO source to provide a 0dBm, CW signal to the demo board LO input port at appropriate LO frequency. 5.Measure the single-sideband noise figure. Where ∆IM3 = PIF – PIM3 Figure 1. Proper Equipment Setup for Return Loss Measurements dc2035af 5 DEMO MANUAL DC2035A QUICK START PROCEDURE Figure 2. Proper Equipment Setup for RF Performance Measurements Figure 3. Equipment Setup for SSB Noise Figure Measurements dc2035af 6 DEMO MANUAL DC2035A HARDWARE SETUP LTC5551 is an ultrahigh dynamic range downconverting mixer with very high input third order intercept point. Accuracy of its performance measurement is highly dependent on equipment setup and measurement technique. The recommended setups are presents in the following pages. The following precautions should be observed: 1.Use high performance signal generators with low harmonic output and low phase noise, such as Rohde & Schwarz SME06 or equivilent. Filter may be used at the signal generators to suppress higher order harmonics. For example, when measuring 2nd order product spurs. 2.A high quality RF power combiner that provide broadband 50Ω termination on all ports, and have excellent port-to-port isolation must be used to get the best RF performance, such as MCLI PS2-17. 3.High performance amplifiers with high IP3 is recommended at the inputs to improve the isolation when performing the two-tone measurements. High isolation minimizes the modulation of the two sources, thus improving the source IP3. 4.Use attenuator pads with good broadband VSWR on the demonstration board’s input and output ports. They provide the improved return loss that can reduce the interstage reflections which can degrade RF performance. 5.Use a high dynamic range spectrum analyzer such as FSEM 30 for linearity measurements. 6.Use narrow resolution bandwidth (RBW) and engage video averaging on the spectrum analyzer to lower displayed average noise level (DANL) in order to improve sensitivity and to increase dynamic range. However, the trade off is increased sweep time. 7.Spectrum analyzer produces its own nonlinearity when overdriven. Generally, 30dB of input attenuation is sufficient for linearity measurements. Appropriate amount of attenuation should be used so that the spectrum analyzer nonlinearity does not degrade the device under test (DUT) RF performance. However, using too much input attenuation will result is higher noise level, and decreased dynamic range. 8.Before starting any RF measurements, the input signal must be calibrated. The input signal IP3 must be verified to be much better than the DUT so that the measurement equipment does not degrade the overall RF measurement result. P1dB Compression Measurement Figure 2 can be modified for the P1dB compression measurement. Turn off one of the input signal generators, sweep the input power so that LTC5551 conversion gain is reduced by 1dB. The input power at which conversion gain is reduced by 1dB is the Input referred 1dB compression point. However, signal generators and amplifiers at the input also introduce additional compression into the signal path. Therefore, the 6dB pad after the combiner is removed for this test so that LTC5551’s compression point is accurately measured. dc2035af 7 DEMO MANUAL DC2035A PCB LAYOUT dc2035af 8 DEMO MANUAL DC2035A PCB LAYOUT dc2035af 9 DEMO MANUAL DC2035A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER CAP., C0G, 2.2pF, ±0.1pF, 50V, 0402 AVX, 04025A2R2BAT2 AVX, 04025A3R9BAT2A Required Circuit Components 1 1 C1 2 1 C2 CAP., C0G, 3.9pF, ±0.1%, 50V, 0402 3 0 X2, R3, C3 0402, OPT 4 2 C4, C6 CAP., 0.56µF, 10%, 10V, X5R, 0603 AVX, 0603ZD564KAT2A 5 2 C5, C7 CAP., 22pF, 50V, 5%, NPO, 50V, 0402 AVX, 04025A220JAT2A 6 2 C8, C9 CAP., X7R, 1000pF, 10%, 50V, 0402 AVX, 04025C102KAT2A 7 5 E1-E5 TURRET, PAD 0.061" MILL-MAX, 2308-2-00-80-00-00-07-0 8 1 J1-J3 CONN., SMA 50Ω EDGE-LAUNCH E. F. JOHNSON, 142-0701-851 9 2 L1, L2 IND., WIRE-WOUND, 470nH, 2%, 0603 COILCRAFT, 0603LS-471XGLB 10 1 X1 IND., WIRE-WOUND, 7.5nH, 0402 COILCRAFT, 0402hp-7N5XJL 11 2 R1, R2 RES., CHIP, 475Ω, 1%, 0402 VISHAY, CRCW0402475RFKED 12 1 T1 TRANSFORMER, SMT, RF WIDEBAND, 4:1 MINI-CIRCUITS, TC4-1W-7ALN+ 13 1 U1 IC., LINEAR TECHNOLOGY, LTC5551IUF LINEAR TECH., LTC5551IUF dc2035af 10 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. A B 5 1. ALL RESISTORS ARE IN OHMS, 0402 2. ALL CAPACITORS ARE IN MICROFARADS, 0402 4 NOTE: UNLESS OTHERWISE SPECIFIED 3 3 C 4 D 5 1 2 1 TECHNOLOGY 2 A B C D DEMO MANUAL DC2035A SCHEMATIC DIAGRAM dc2035af 11 DEMO MANUAL DC2035A DEMONSTRATION BOARD IMPORTANT NOTICE Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions: This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations. If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive. Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and observe good laboratory practice standards. Common sense is encouraged. This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright © 2004, Linear Technology Corporation dc2035af 12 Linear Technology Corporation LT 0813 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2013