Description Demonstration circuit 09A is optimized for evaluation of the LTC 99 low power direct quadrature modulator. The balanced I and Q baseband input ports can be either AC- or DC-coupled to a source with a common mode voltage level of about.v. Fixed LC networks on the LO and RF ports cover a continuous 90MHz to 00MHz range. The SPI interface controls the supply current, modulator DEMO MANUAL DC09A LTC99 0MHz to 00MHz Low Power Direct Quadrature Modulator gain, and allows optimization of the LO carrier feedthrough and side-band suppression. Design files for this circuit board are available at http://www.linear.com/demo/dc09a L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and QuikEval is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Measurement Setup BB SIGNAL SOURCE (V CMBB =.V DC ) I + I Q + Q SPECTRUM ANALYZER db db LO SIGNAL SOURCE DC09 F0 + DC POWER SUPPLY (.V) Figure. Test Setup for RF Performance Measurements dc09afa
DEMO MANUAL DC09A Absolute Maximum Input Ratings Supply Voltage...8V Common Mode Level of BBPI, BBMI, and BBPQ, BBMQ...V LOL, LOC DC Voltage... ±0.V LOL, LOC Input Power...0dBm Voltage on Any Pin... 0.V to + 0.V T JMAX... 0 C Notes on Test Equipment and Setup Use high performance signal generators with fully configurable differential I and Q outputs, such as the Rohde & Schwarz SMJ00A vector signal generator or equivalent. Use narrow resolution bandwidth (RBW) and engage video averaging on the spectrum analyzer to lower the displayed average noise level (DANL) in order to improve sensitivity and to increase dynamic range. The trade-off is increased sweep time. Spectrum analyzers can produce significant internal distortion products if they are overdriven. Generally, spectrum analyzers are designed to operate at their best with about 0dBm to 0dBm at their input filter or preselector. Sufficient spectrum analyzer input attenuation should be used to avoid saturating the instrument, but too much attenuation reduces sensitivity and dynamic range. Case Operating Temperature Range... 0 C to 0 C Storage Temperature Range... C to 0 C CAUTION: This PART is sensitive to electrostatic discharge (ESD). Observe proper ESD precautions when handling the LTC99. Before taking measurements, the system performance should be evaluated to ensure that: ) clean input signals can be produced ) the spectrum analyzer s internal distortion is minimized ) the spectrum analyzer has enough dynamic range and sensitivity ) the system is accurately calibrated for power and frequency. Digital modulation often requires DC coupling and flat frequency response. For best EVM performance with complex modulation, the RC networks at the baseband I/Q inputs are not required. Quick Start Procedure. Remove the demonstration circuit from its protective packaging in an ESD-safe working area.. Turn off the DC power supply as well as the baseband and LO signal sources outputs.. Connect all test equipment as show in Figure.. Make sure jumper JP is installed and the jumper JP is installed at the - position.. Slowly increase the supply voltage to.v. Do not exceed.8v.. Turn on the baseband signal source. Set the baseband common mode bias to.v. 7. Verify the total supply current is approximately 8mA. The demonstration circuit is now turned on and is ready for measurements. 8. Turn on the output of the LO source and apply a 9.8MHz, 0dBm CW Signal. 9. Set the baseband signal source to provide a 00kHz, 00mV P-P(DIFF) baseband input signal. The I and Q channels should be 90 shifted and set for lower sideband selection. 0. Measure the modulator s RF output on the Spectrum Analyzer at 9.7MHz. dc09afa
DEMO MANUAL DC09A Quick Start Procedure. Calculate the Voltage Conversion Gain: Gain = 0 log (V RF(OUT)(0Ω) / V IN(DIFF)(I OR Q) ). Measure the Output db Compression Point by increasing the input signal level until the Voltage Conversion Gain degrades by db.. Measure the Image Rejection at 9.9MHz.. Measure the LO Leakage at 9.8MHz.. Connect the DC90B to the DC09A with the ribbon cable provided. Make sure jumper JP on the DC90B is set to.v.. Run QuikEval to start the GUI associated with the LTC99. 7. The turn off procedure is the reverse of the turn on procedure. Make sure is removed after V EN. Demo Board Schematic.V EN E E E FB 0Ω AT 00MHz C.7µF JP C, 000pF VCC SDO SDI SCLK CS V CTRL LO TTCK E J E R, Ω L, 9nH C, pf C 0 9 EN SDO SDI SCLK CSB V CTRL RF RF LOL LOC TTCK LTC99IUF RF RF RF RF 8 C 7 0.0µF J RF TEMP BBMI E J R, 0Ω TEMP BBPI BBMI BBPQ BBMQ 7 8 9 0 R, 0Ω J BBMQ BBPI J R, 0Ω R, OPT R, OPT R, 0Ω J BBPQ R8 9.9Ω R9 9.9Ω * * R0 9.9Ω R 9.9Ω E7 C C7 C8 C9 DC09 F0 * REMOVE THE RC NETWORK FOR BEST EVM WITH COMPLEX DIGITAL MODULATION. Figure. Low Power I/Q Modulator Schematic dc09afa
DEMO MANUAL DC09A Demo Board schematic JP E8 R 00k U NC7WZ7PX R k C C0.pF R k C.pF CS SCLK U NC7WZ7PX R k C.pF SDI ISO_7V_UNREG ISO_V_pv_REG ISO_CSb ISO_SCK_SCL ISO_SDA_MOSI ISO_MISO EE_ EE_SDA EE_SCL EE_ GPI0 ISO_ ISO_ ISO_ P HD-X7.0.79 8 7 0 9 R.99k C R0 00Ω R.99k U 7LVCTGW VCC_A VCC_B R.99k C DIR U LC0 8 7 WP SCL SDA A0 A A V SS C R9 k DC09 F0 C8.pF R8.99k C7 SDO Figure. Demo Board SPI Interface dc09afa
DEMO MANUAL DC09A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components C CAP., XR,.7µF, 0%, V, 00 MURATA, GRM88RC7KAAJD C CAP., C0G, 000pF, %, 0V, 00 MURATA, GRMCH0JA0D 0 C, C C9, C, C C7 CAP., X7R,, 0%, V, 00 MURATA, GRMR7C0KA88D C CAP., X7R, 0.0µF, 0%, V, 00 MURATA, GRMR7C0KA0D C CAP., COG, pf, %, 0V, 00 MURATA, GRMCH0JA0D C0, C, C, C8 CAP.,COG,.pF,+/-.pF, V, 00 MURATA, GRMCERBZ0D 7 E, E, E, E7, E8 TESTPOINT, TURRET,.09" MILL-MAX, 0--00-80-00-00-07-0 8 E, E, E TESTPOINT, TURRET,.0" MILL-MAX, 08--00-80-00-00-07-0 9 FB FERRITE BEAD, Ω @00MHz TDK, MPZ08SAT 0 JP HEADER, PIN, 0.079 SINGLE ROW SULLINS, NRPN0PAEN-RC JP HEADER, PIN, 0.079 SINGLE ROW SULLINS, NRPN0PAEN-RC XJP, XJP SHUNT, mm Ctrs. SAMTEC, SN-BK-G J J CONN., SMA, 0Ω, EDGE-LANCH E.F.JOHNSON, -070-8 L IND., 9nH, 00HP COILCRAFT, 00HP-9NXJLU P HEADER, X7PIN, 0.079CC MOLEX, 878-0 R RES., CHIP, Ω, %, 00 VISHAY, CRCW00R00FNED 7 0 R, R OPT, 00 8 R, R, R, R RES., CHIP, 0Ω, 00 VISHAY, CRCW000000Z0ED 9 R8, R9, R0, R RES., CHIP, 9.9Ω, %, 00 VISHAY, CRCW009R9FKED 0 R, R, R RES., CHIP,.99K, %, 00 VISHAY, CRCW00K99FKED R8, R9, R, R, R RES., CHIP, K, %, 00 VISHAY, CRCW00K00FKED R0 RES., CHIP, 00Ω, %, 00 VISHAY, CRCW0000RFKED R RES., CHIP, 00K, %, 00 VISHAY, CRCW0000KFKEA U IC., LTC99, QFN--X LINEAR TECHNOLOGY, LTC99IUF#PBF U IC, EEPROM KBIT 00KHZ 8TSSOP MICROCHIP TECH., LC0-I/ST U, U I.C., DUAL BUFFER SCHMT TRIG UHS SC70 FAIRCHILD SEMI., NC7WZ7PX 7 U I.C., DUAL TRANSCEIVER ST TSSOP NXP, 7LVCTGW, 8 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT DC09A 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. dc09afa
DEMO MANUAL DC09A 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 0 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 0 McCarthy Blvd. Milpitas, CA 90 Copyright 00, Linear Technology Corporation dc09afa LT REV A PRINTED IN USA Linear Technology Corporation 0 McCarthy Blvd., Milpitas, CA 90-77 (08) -900 FAX: (08) -007 www.linear.com LINEAR TECHNOLOGY CORPORATION 0