TQ5635 WIRELESS COMMUNICATIONS DIVISION GND/LNA Gain GND/LNA Gain DATA SHEET Mixer Vdd LNA Out GND RF In 3 V PCS LNA/Mixer Receiver IC Active Bias 1 MXR In LNA GND Mixer Features LO Vdd GND ?? Single 3.0 V Operation LNA Bias active bias ?? Adjustable Gain/IP3/Current LO In LO Buffer IF Amp ?? Low Current Operation ?? Few external components LNA Vdd GND IF Out ?? QFN 3x3 mm, 16 Pin Leadless Plastic Package GIC Product Description ?? High Input IP3 The TQ5635 is an LNA-Downconverter optimized for use in the Korea CDMA PCS bands. The integrated LNA has a single high gain mode that provides over 15 dB of gain, and features very low NF and excellent IP3. An external resistor controls LNA bias, making LNA Idd adjustable. The integrated mixer features very high IP3 and provision for external adjustment of gain, IP3, and Idd. Because of the external LO tuning inductor, IF’s in the range of 85 to 200Mhz can be used. The excellent RF performance with low current coupled with very small lead-less plastic package is ideally suited for PCS band mobile phone. Applications ?? PCS band CDMA mobile Applications Electrical Specifications 1 Parameter ?? Low Noise Figure ?? Wireless data applications Min Typ Max Units RF Frequency 1855 MHz Conversion Gain 24.5 dB Noise Figure 2.3 dB Input 3rd Order Intercept -4.75 dBm DC supply Current 23.4 mA Note 1. Test Conditions: Vdd=+2.8V, TC=+25C, RF=1855MHz, RF in =-30dBm LO=1635MHz, LO input=-4dBm, IF=220MHz 2. Data includes image reject filter (Sawtek P/N: 356083) insertion loss of 1.7 dB For additional information and latest specifications, see our website: www.triquint.com 1 TQ5635 Data Sheet Absolute Maximum Ratings Parameter Symbol Minimum Nominal Maximum Units Tstore -40 25 125 deg. C Tc -40 25 85 deg. C VDD 0 2.8 5.0 V Voltage to any non supply pin - - - - VDD+0.5V Power Dissipation P - - 100 mW Signal Power Ps - - 20 dBm Storage Temperature Case Temperature w/bias Supply Voltage Note 1. All voltages are measured with respect to GND (0V), and they are continuous. 2. Absolute maximum ratings as detailed in this table, are ratings beyond which the device’s performance may be impaired and/or permanent damage may occur. Typical Electrical Characteristics –Korea PCS band, Cascade Parameter Conditions RF Frequency Min. 1840 IF Frequency LO input -7 Supply voltage Input 3rd Order Intercept1,3,4 21.5 2. 2 -4 1870 MHz MHz -1 -6.5 dB 2.8 -4.75 23.4 dBm V 24.5 2.3 Supply Current2,3 3. 4. Units 2.8 1,3,4 Noise Figure1,4 Note 1. Max. 220 level2 Conversion Gain Typ/Nom dB dBm 25.0 mA Test Conditions (devices screened for Conversion Gain, Noise Figure, and IIP3 to the above limits): Vdd = +2.8V, RF = 1855MHz, LO = 1635MHz, IF = 220MHz, LO input = -4dBm, RF input = -30dBm, TC = +25? C, unless otherwise specified. Min./Max. limits are at +25? C case tempera ture unless otherwise specified. Conversion Gain and Idd depends on the values of the two resistors used in the GIC circuit and LNA Bias resistor. Data includes image reject filter (Sawtek P/N: 356083) insertion loss of 1.7 dB For additional information and latest specifications, see our website: www.triquint.com TQ5635 Data Sheet Typical Electrical Characteristics – Korea PCS band, LNA only: Parameter Conditions RF Frequency Input 1,3 Figure1 3rd Supply Order Typ/Nom 1840 Conversion Gain Noise Min. Intercept1,3 Current3 Max. Units 1870 MHz 17.5 dB 1.8 dB 1.1 dBm 7.0 mA Note 1. Test Conditions: Vdd = +2.8V, RF = 1855MHz, LO = 1635MHz, IF = 220MHz, LO input = -4dBm, RF input = -30dBm, TC = +25?C, unless otherwise specified. 2. 3. Min./Max. limits are at +25? C case temperature unless otherwise specified. Conversion Gain and Idd depends on the values of the Bias resistor. Typical Electrical Characteristics – Korea PCS band, Mixer only: Parameter Conditions RF Frequency Min. 1840 IF Frequency Conversion Gain Noise Input 1,3 Figure1 3rd Supply Order Typ/Nom Intercept1,3 Current3 Max. Units 1870 MHz 220 MHz 9.1 dB 8.2 dB 11.6 dBm 16.5 mA Note 1: Test Condition: Vdd = +2.8V, RF = 1855MHz, LO = 1635MHz, IF = 220MHz, LO input = -4dBm, RF input = -30dBm,TC = +25?C, unless otherwise specified.. 2. 3. 4. Min./Max. limits are at +25? C case temperature unless otherwise specified. Conversion Gain and Idd depends on the values of the two resistors used in the GIC circuit. Data includes image reject filter (Sawtek P/N: 356083) insertion loss of 1.7 dB For additional information and latest specifications, see our website: www.triquint.com 3 TQ5635 Data Sheet Typical Test Circuit for CDMA KPCS: Test Conditions (Unless Otherwise Specified): Vdd = +2.8V, RF = 1855MHz, LO = 1635MHz, IF = 220MHz, LO input = -4dBm, RF input = -30dBm, TC = +25?C B+ AUXin NC C11 Vdd F1 Vdd R8 GND L1 RF In MX VD D RFin LNA Out GND LNA Mode C6 L4 MXR In C7 GND C8 TQ5635 Vdd R7 IF Bias V DD GND LNA Bias IF Out C5 LOin V DD GND L2 LO In R6 C10 Vdd R9 C9 TOKO R12 R16 L3 TOKO C14 0603 C13 C15 IFout RL 021401 Bill of Material for TQ5635 LNA/Downconverter Mixer for GIC tuning plots Component Reference Designator Receiver IC Part Number Value TQ5635 Size Manufacturer 3x3mm TriQuint Semiconductor Capacitor C11, C13 0.1uF 0402 Capacitor C5 2.2pF 0402 Capacitor C6 1.0pF 0402 Capacitor C7 1000pF 0402 Capacitor C8, C9, C10,C13 1000pF 0402 Capacitor C14 15pF 0402 Capacitor C15 12pF 0402 Inductor L1 3.9nH 0402 Coil Craft Inductor L2 5.6nH 0402 TOKO Inductor L3 56nH 0603 TOKO Inductor L4 3.3nH 0402 TOKO Resistor R8, R16 3.3O 0402 Resistor R6 20O 0402 Resistor R7 2.7KO 0402 4 * LNA Bias For additional information and latest specifications, see our website: www.triquint.com TQ5635 Data Sheet Resistor R9 Resistor R12 * GIC RF Saw Filter F1 856083 1.8O 0402 39O 0402 2x2mm SAWTEK CDMA KPCS Band Typical LNA Performance Test Conditions (Unless Otherwise Specified): Vdd=+2.8V, Tc=+25C, RF = 1852MHz, LO = 1635MHz, I F = 220MHz Conversion Gain vs Vdd vs Freq Conversion Gain vs Vdd vs Temp 19 Conversion Gain (dB) Conversion Gain (dB) 20 19 18 17 16 -40C 25C 18.5 18 17.5 17 15 2.5 2.7 2.9 3.1 2_7V 3_2V 16.5 85C 3.3 16 1830 3.5 1840 Vdd (V) Conversion Gain vs Vdd vs Temp 1870 1880 Input IP3 vs Vdd vs Temp 3 19 2 IP3 (dBm) Conversion Gain (dB) 1860 RF Freq (MHz) 20 18 17 1 0 16 -40C 25C 85C -40C 15 2.5 2.7 2.9 3.1 3.3 3.5 2.5 Input IP3 vs Temperature vs Freq 85C 2.7 2.9 3.1 Vdd (V) 3.3 3.5 Idd vs Vdd vs Temperature 9 1.5 8 Idd (mA) 2 1 0.5 7 6 -40C 0 1830 25C -1 Vdd (V) IP3 (dBm) 1850 2_8V 3V 1840 25C 1850 1860 RF Freq (MHz) 85C 1870 1880 -40C 25C 85C 5 2.5 2.7 2.9 3.1 Vdd (V) 3.3 For additional information and latest specifications, see our website: www.triquint.com 3.5 5 TQ5635 Data Sheet Idd vs Temperature vs Frequency Noise Figure vs Temp vs Frequency 9 2.5 Noise Figure (dB) Idd (mA) 8 7 6 -40C 5 1830 1840 25C 1850 1860 2.1 1.7 1.3 0.9 -40C 85C 1870 1880 0.5 1830 1840 1850 Noise Figure vs Vdd vs Temp 2.5 Noise Figure (dB) 2.1 1.7 1.3 0.9 25C 85C 0.5 2.5 2.7 2.9 3.1 3.3 3.5 Vdd (V) 6 1860 RF Freq (MHz) RF Freq (MHz) -40C 25C For additional information and latest specifications, see our website: www.triquint.com 85C 1870 1880 TQ5635 Data Sheet CDMA KPCS Band Typical Mixer Performance Test Conditions (Unless Otherwise Specified): Vdd=+2.8V, Tc=+25C, RF = 1852MHz, LO = 1635MHz, I F = 220MHz, LO input = 4dBm Gain vs Vdd vs Frequency 13 11 12 10.5 Conversion Gain (dB) Conversion Gain (dB) Gain vs Vdd vs Temperature 11 10 9 8 -40C 25C 85C 7 2.5 2.7 2.9 3.1 3.3 3.5 10 9.5 9 8.5 8 1830 3.7 Vdd (V) 1840 1850 2_8V 3V 1860 1870 1880 RF Freq (MHz) Conversion Gain vs LO vs Freq Gain vs Temperature vs Frequency 13 10 Conversion Gain (dB) Conversion Gain (dB) 2_7V 3_5V 12 11 10 9 8 -40C 7 1830 1840 25C 1850 1860 85C 1870 9.5 9 8.5 -1dBm 8 1830 1880 1840 -4dBm 1850 1860 -7dBm 1870 1880 RF Freq (MHz) RF Freq (MHz) Input IP3 vs Temp vs Frequency Input IP3 vs Vdd vs Temperature 14 14 13 13 IP3 (dBm) IP3 (dBm) 12 12 11 10 11 10 9 9 -40C 25C 85C 8 2.5 2.7 2.9 3.1 3.3 Vdd (V) 3.5 3.7 8 7 1830 -40C 1840 1850 25C 1860 85C 1870 1880 RF Freq (MHz) For additional information and latest specifications, see our website: www.triquint.com 7 TQ5635 Data Sheet Idd vs Vdd vs Temperature 22 11.9 20 Idd (mA) IP3 (dBm) Input IP3 vs LO Drive vs Frequency 12.3 11.5 11.1 18 16 14 10.7 -1dBm 10.3 1830 -4dBm -40C -7dBm 1840 1850 1860 1870 2.5 1880 2.7 2.9 Idd vs Temperature vs Frequency 3.3 3.5 3.7 10 9 Noise Figure (dB) 18 Idd (mA) 3.1 Noise Figure vs Vdd vs Temp 19 17 16 15 8 7 6 -40C 5 -40C 14 1830 25C 85C 4 1840 1850 1860 1870 1880 2.5 2.7 2.9 Noise Figure vs Temp vs Frequency 9 7 5 -40C 1840 1850 25C 1860 3.1 Vdd (V) 11 3 1830 25C 85C RF Freq (MHz) Noise Figure (dB) 85C Vdd (V) RF Freq (MHz) 85C 1870 1880 RF Freq (MHz) 8 25C 12 For additional information and latest specifications, see our website: www.triquint.com 3.3 3.5 3.7 TQ5635 Data Sheet CDMA KPCS Band Typical Cascade Performance Test Conditions (Unless Otherwise Specified): Vdd=+2.8V, Tc=+25C, RF = 1852MHz, LO = 1635MHz, I F = 220MHz, LO input = -4dBm Gain vs LO vs Frequency Gain vs Vdd vs Temperature 28 Conversion Gain (dB) Conversion Gain (dB) 28 26 26 24 24 22 22 -40C 25C -1dBm 85C 20 1830 20 2.5 2.7 2.9 3.1 Vdd (V) 3.3 1840 -4dBm 1850 1860 RF Freq (MHz) 3.5 -7dBm 1870 1880 IIP3 vs Vdd Vs Frequency Gain vs Vdd vs Frequency -3 29 IIP3 (dBm) Conversion Gain (dB) -4 27 25 -5 -6 2_7 3 23 2_7V 3_2V 21 1830 1840 1850 2_8V 3V 1860 RF Freq(MHz) -7 1830 1870 1840 1850 2_8 3_2 1860 1870 1880 Frequency (MHz) 1880 IP3 vs Vdd vs Temperature Gain vs Temperature vs Frequency -2 -3 27 IP3 (dBm) Conversion Gain (dB) 29 25 -4 -5 -6 23 -7 -40C 21 -40C 19 1830 1840 1850 25C 1860 85C 1870 1880 25C 85C -8 2.5 2.7 2.9 3.1 3.3 3.5 Vdd (V) RF Freq (MHz) For additional information and latest specifications, see our website: www.triquint.com 9 TQ5635 Data Sheet IP3 vs Temperature vs Freq Noise Figure vs Vdd vs Temp 0 Noise Figure (dB) 5 IP3 (dBm) -2 -4 -6 -8 -40C -10 1830 25C 4 3 2 1 -40C 85C 1850 1860 1870 2.5 1880 2.7 2.9 -4 4 Noise Figure (dB) -3 IP3 (dBm) -5 -6 -7 1840 -4dBm 1850 1860 3.5 3 2 1 -7dBm 1870 3.3 Noise Figure vs Temp vs Freq 5 -1dBm 3.1 Vdd (V) IP3 vs LO Drive vs Frequency -9 1830 85C 0 1840 RF Freq (MHz) -8 25C -40C 0 1830 1880 1840 25C 1850 RF Freq (MHz) 1860 85C 1870 1880 RF Freq (MHz) Idd vs Vdd vs Temperature Noise Figure vs LO vs Frequency 28 2.6 26 2.4 Idd (mA) Noise Figure (dB) 2.5 2.3 24 22 2.2 20 2.1 -1 2 1830 -4 -40C 85C 18 1840 1850 1860 1870 1880 2.5 2.7 Frequency (MHz) 10 25C -7 For additional information and latest specifications, see our website: www.triquint.com 2.9 3.1 Vdd (V) 3.3 3.5 TQ5635 Data Sheet Idd vs Temperature vs Frequency 26 25 Idd (mA) 24 23 22 21 20 1830 -40C 1840 1850 25C 1860 85C 1870 1880 RF Freq (MHz) For additional information and latest specifications, see our website: www.triquint.com 11 TQ5635 Data Sheet The IF signal from the mixer is fed to an amplifier. The IF Pinout Description: amplifier is an open drain type with output at Pin 7. An The TQ5635 is a complete front-end for a Korea high band CDMA handset receiver. It combines a high IP3 low noise amplifier, a high intercept mixer, and an IF amplifier. The LNA uses an off-chip matching network which connects to the input at pin 2. The amplifier was designed so that the match for maximum gain also gives very low noise figure. The LNA has a single high gain mode that typically provides 15-16dB of gain. The LNA also provides several ways of setting gain and external matching circuit is required to match the IF output to a filter. The IF amplifier also has a GIC pin (Gain-InterceptCurrent). It is used to set the DC current and gain of the IF stage. Application Information: Half IF Spur Rejection Considerations: The TQ5635 has a single ended mixer so Half-IF spur rejection is set by the image filter. Thus we do not intercept in the design phase. The LNA FET source is recommend using an IF that is less than 2.5 times the image brought out to Pins 15 and 16, where a small value of filter. inductance to ground can be added. The inductor can be Grounding: discrete or simply a small length of pc board trace. Several With good layout techniques there should not be any stability dB of adjustment is possible. For most applications, maximum gain will be desired. In that case, pins 15 and 16 problems. Poor circuit board design can result in a circuit that should be connected to ground with multiple vias. A bias oscillates. Good grounding is especially important for the resistor on pin 4 is used to set the LNA supply current. A nominal value of 2.7kohm is recommended. provides one more potential ground loop path. One could The LNA output signal is at Pin 14. It is a 50 ohm line and can be connected directly to a SAW image filter. The image filter TQ5635 since it uses an outboard LO tuning inductor that use the evaluation board as an example of proper layout techniques. output connects to the mixer input at Pin 12. The mixer It is important to position the LO tuning, GIC, and IF matching receives its LO via a buffer which amplifies the signal from Pin components as close to the chip as possible. If the 9. The buffer transistor drain comes out of Pin 10 where it components are far enough away they and their connects to an external LO tuning inductor. corresponding pc board traces can act as quarter wave resonators in the 5-10Ghz region. If both the IF and the LO GND/LNA Gain GND/LNA Gain Mixer Vdd LNA Out paths to ground resonate at the same frequency, oscillation can result. Active Bias 1 GND RF In It is most important that the ground on the GIC bypass cap, MXR In LNA GND the ground on the LO tuning bypass capacitor, and the IF shunt cap ground return back to the chip grounds with minimal inductance (Figure 2). Mixer LO Vdd GND Also, improving the ground at the LO tuning inductor bypass cap will increase circuit Q. Thus mixer drive is improved with LNA Bias active bias LO Buffer IF Amp LO In a resultant higher IP3. Improved ground here means minimal inductance between the chip ground pins and the other LNA Vdd GND IF Out GIC Figure 1. TQ5635 Block diagram ground return points. Although it is not a stability issue, proper grounding of pins 15 and 16 is necessary for maximum LNA gain. Multiple vias to ground should be placed very close to those pins. 12 For additional information and latest specifications, see our website: www.triquint.com TQ5635 Data Sheet Use multiple ground vias for maximum LNA gain Figure 3 shows a much simplified block diagram of the LNA, GND RF In TQ5635 MXR In quiescent current in the IF amplifier is set by the GIC network. GND Both the filter and the mixer terminate the RF signal with VDD IF Bias IF Out GND VDD GND LNA Bias LNA, passes through the image filter, and is converted down to the IF where it is amplified by the IF output FET. The VDD GND LNA Out GND image filter, and mixer. The RF signal is amplified by the 50ohms. LO In Vdd However, the situation is much different with the LO signal. At the LO frequency the image filter looks like a short circuit. Vdd Minimize These Lengths IFout Some LO energy leaks out of the mixer input, bounces back off of the image filter and returns back into the mixer with some phase or delay. The delayed LO signal mixes with the normal LO to create a DC offset in the passive FET. A DC Figure 2. Critical signal Paths blocking capacitor prevents the offset voltage from affecting IF stage current. It has been found empirically that varying the delay between the filter and mixer can have positive or negative Mixer – Filter Interaction: consequences on IP3, CG, and NF. It is for this reason that Before attempting a new TQ5635 application, it is important to understand the nonlinear interaction between the image filter an LC network is useful between the SAW and mixer input, and the mixer subcircuit. The device IP3 is a strong function the RF frequency without any external components. even though the mixer input can have an adequate match at of this interaction. For this reason it is helpful to consider the filter and mixer as one nonlinear block. 25-100 ohms at RFshort circuit at LO LNA Portion of TQ5635 LO Leakage LNA Out RF in Mixer Portion of TQ5635 IF Output FET Mixer IF Output Blocking Cap 12 2 14 7 Idd Mixer in band pass IF + DC Offset LO Leakage ?????? LO IF to GIC 9 8 (LO Leakage ?????+ LO) = DC Offset at Mixer IF Output Figure 3. Non-linear filter-Mixer Interaction For additional information and latest specifications, see our website: www.triquint.com 13 TQ5635 Data Sheet LNA S-Parameters : S-Parameters for the TQ5635 LNA taken in the high mode. We have not included noise parameters since for this device Gamma-Opt is very close to the conjugate match. 14 Figure 4: LNA S11 Figure 6: LNA S21 Figure 5: LNA S12 Figure 7: LNA S22 For additional information and latest specifications, see our website: www.triquint.com TQ5635 Data Sheet SUGGESTED STEPS FOR TQ5635 TUNING: The following order of steps is recommended for applying the 1. Determine LNA Bias Resistor Value and Source Inductor Value TQ5635. They are described in detail in the following sections: For most designs we recommend an LNA bias resistor of 2.7K Lay out board consistent with the grounding guidelines at the ohms. All of the datasheet specs assume that value of resistor. However, if LNA Idd < 7.5 mA is desired, then the resistor can beginning of this note. See section 1 regarding LNA source inductor. be made larger. Refer to Figure 8 for graphs of LNA performance vs. bias resistor. 1. Determine the LNA bias resistor value and source inductor value Please keep in mind that there are implications of reduced LNA bias that are not reflected in IP3. For example, the LNA is 2. Determine the LNA input matching network component values. Test the LNA by itself. 3. For the mixer, experimentally determine proper LO tuning normally in front of the image filter so that it may need resistance to blocking or other types of distortion that are not adequately described by the IP3 figure of merit. components. This step needs to be done first since all of the later tuning is affected by it. 5635 LNA NF, Gain, IIP3 and Idd vs bias resistor 4. Determine a tentative GIC network. It will have to be finetuned later, since the image filter interaction will affect device current. dB 5. Synthesize a tentative IF output match. It may have to be fine-tuned later, as the final GIC configuration affects IF stage current. LO is turned ON. Idd (mA) 12 18 16 11 14 10 12 NF Gain IIP3 Idd 9 6. Experimentally determine a tentative mixer RF Input match. 10 8 LO is turned ON. Test the filter-mixer cascade. Verify that 8 7 the device has adequate IP3. If not, another RF Input 6 6 matching topology can be tried. 4 5 2 4 7. Fine tune GIC components for needed Idd. LO is turned ON. 0 3 1.1 8. Check IF match to see if it still is adequate. LO is turned ON. 1.5 2.2 2.7 3.3 4.7 6.8 8.2 10 Bias resistor (kOhms) 9. Test the device as a whole - LNA, filter, mixer Figure 8: Gain, IIP3, Idd, and NF as a Function of Rbias For additional information and latest specifications, see our website: www.triquint.com 15 TQ5635 Data Sheet For most applications needing maximum LNA gain, it component values on the evaluation board can be will probably be sufficient to simply ground pins 15 used for a starting point. Alternately, a network can and 16 as shown in the second diagram in Figure 9. be synthesized from the S-parameter values at the However, in some cases a small amount of inductance may be needed from pins 15 and 16 to end of this note. ground in order to lower the LNA gain. Because of stray inductance on the application board layout, it is 3. LO Buffer Tuning difficult to give a precise value of L as a function of The drain of the LO buffer is brought out to pin 10 gain reduction. The first diagram in Figure 9 where it is fed DC bias via an inductor. The inductor illustrates one way of doing this. A short is placed resonates with the internal and external parasitic across the inductor until the needed gain is arrived at. capacitance associated with that pin. For maximum performance the resonance must be at or near the desired LO frequency. Figure 10 shows a properly 2. Determine the LNA Matching Network performance versus frequency. We have also found adjustment to the L and C values may be needed for empirically that tuning the LO slightly higher in optimum noise figure. If the design uses 5-8mil frequency results in much better LO input and RF dielectric FR4 board, then it is likely that the input matches. VDD IF Bias IF Out VDD LNA Bias GND GND LO In For Lower Gain: add a small inductance to pins 15 and 16 GND RF In TQ5635 GND VDD GND LNA Bias LO In Recommended: Ground pins 15 and 16 for maximum gain Figure 9: LNA Source Inductor Realization 16 MXR In IF Bias GND IF Out TQ5635 GND GND RF In MXR In VDD GND V DD once a match to 50ohms is attained, only a slight LNA Out side of the slope. Thus there is less change in GND that the desired band is on the lower, more gradual match is very close to the conjugate match. Thus V DD TQ5635 LNA was designed so that the optimum noise LNA Out that the LO is tuned slightly higher in frequency, so GND simpler than designing with discrete transistors. The GND Matching network design for the TQ5635 LNA is much tuned LO buffer. Notice that the LO frequency range of interest is to the left of the peak. We recommend For additional information and latest specifications, see our website: www.triquint.com TQ5635 Data Sheet Figure 10: Suggested LO Tuning Response A first approximation to the needed inductor can be found by Figure 11 shows the recommended test setup for tuning the the following equation: TQ5635 LO buffer. A network analyzer is set to the center of the LO band +/- 300Mhz, with an output power of –4dBm. It is 1 L = ---------------- - 1nH important to set the frequency range to be quite a bit wider where C=1.5pF than the LO band, so that the shape of the tuning curve can be seen. A two port calibration is performed and the analyzer C (2*pi*F)2 It is likely that when the design is prototyped, the needed inductance will fall between two standard inductor values. It is advised to use a slightly larger inductor and then use the bypass capacitor for fine tuning. When using this method it is important to isolate the tuning inductor/bypass cap node from the Vdd bus, since loading on the bus can affect tuning. A is set to monitor S21. Port 1 of the analyzer is connected to the LO port of the TQ5635, while Port 2 is connected via cable to a short length of semi- rigid coaxial probe. The center of the probe should protrude 1 to 2 mm beyond the ground shield. The end of the probe with the exposed center conductor is held close to the LO tuning inductor. resistor of 3.3ohm to 20ohm has been found to work well for this purpose (R2). For additional information and latest specifications, see our website: www.triquint.com 17 TQ5635 Data Sheet RF In inductance back to the die. Furthermore, although some COAXIAL PROBE V DD GND GND LNA Out GND since there is always some package and bond wire additional IP3 performance may be gained by increasing the VDD MXR In quiescent current, in practice it makes no sense to increase Idd beyond that which provides maximum input intercept. At GND TQ5635 VDD IF Bias IF Out V DD LNA Bias GND GND LO In some point IP3 is limited by the mixer FET, and no further increase in input intercept can be obtained by adjusting the IF stage. LO IN There are two GIC schemes that are recommended for the PORT 1 TQ5635 (Figure 12). The first uses a small resistor (1.0 to 5 MEASURE S21 ohms) in series with a bypass capacitor to set the AC gain. NETWORK ANALYZER The IF stage current is then set by the larger resistor (40 to 80 ohms) that connects directly from the GIC pin to ground. The small degeneration resistor lowers the IF stage gain. Figure 11: LO Tuning Test Setup The second scheme, which is recommended for maximum gain, uses a resistor in parallel with capacitor. The resistor sets the DC current, while the capacitor bypasses it at the IF 4. GIC Network Design frequency. For highest gain, place the capacitor as close to The GIC pin on the TQ5635 is connected internally to the Pin 7 as possible. Try to avoid capacitors which are self- source of the IF output stage. By adding one or two resistors resonant at the IF frequency. and a capacitor to this pin, it is possible to vary both the IF stage AC gain, and the IF stage quiescent current. However, Here is an approximate equation for Rgic as a function of IF there is a limit to the amo unt of gain increase that is possible, GIC PIN stage Idd: Chip GND Rgic ~ 0.6 / IDD_IF GIC PIN 0 to 5 ohms 40 to 80 ohms AC degen 40 to 80 ohms sets IF current sets IF current Zc bypass at IF Freq Figure 12: GIC Pin Networks 18 For additional information and latest specifications, see our website: www.triquint.com Chip GND Zc bypass at IF Freq TQ5635 Data Sheet circuit topology must contain either a RF choke or shunt dB 5635 Mixer NF, Gain, IIP3 and Idd vs GIC resistor inductor. Idd (mA) 16 12 NF Gain 11 IIP3 14 Idd 10 For purposes of 50 ohm evaluation, the shunt L, series C, shunt C circuit shown in Figure 14 is the simplest and requires the fewest components. DC current can be easily injected through the shunt inductor and the series C provides a DC block, if needed. The shunt C, in particular can be used to 9 12 improve the return loss and to reduce the LO leakage. The circuit is used on our evaluation board. 8 10 7 For matching into a filter, the circuit of Figure 15 works well. The network provides the needed impedance transformation 6 47 56 68 82 100 8 110 GIC resistor (kOhms) Figure 13: Mixer Performance as a Function of Rgic with a lower loaded Q using reasonable inductor values. Thus matching circuit loss is minimized. The ratio between (L1+L2) and L2 is proportional to the square root of the impedances to be matched, Z1 and Z2. The sum of L1 and L2 must be chosen so that the total inductance resonates with the SAW input capacitance. If this resonant frequency is 5. IF Match Design much higher than the IF frequency, then Copt can be added to The Mixer IF output (Pin 7) is an "open-drain" configuration, lower it. Please note that because of parasitic capacitance allowing for flexibility in efficient matching to various filter and the discrete values of commercial inductors, the formulas types and at various IF frequencies. An optimum lumped- of Figure 15 only serve as a starting point for experimentation. element-matching network must be designed for maximum In order to minimize loss, any inductors used should have high Q. Typically 0805 size inductors perform better than the 0603 TQ5635 conversion gain and minimum matching network loss. When designing the IF output matching circuit, one has to consider the output impedance, which will vary somewhat depending on the quiescent current and the LO drive. The IF frequency can be tuned from 45 to 400 MHz by varying component values of the IF output matching circuit. The IF output pin also provides the DC bias for the output FET. In the user's application, the IF output is most commonly connected to a narrow band SAW or crystal filter with size. If 0603 inductors must be used for space considerations, make certain to use High-Q types. It is possible to introduce 3dB of additional loss by using low Q inductors. Additionally, it is recommended to place the IF filter very close to the TQ5635. If the two are far apart a transmission line will be needed between them. In that case two matching networks will be needed, one to match down to 50ohms and one to match back up to 1000ohms. Twice the loss can be expected for such a scheme. impedance from 500 -1000? with 1 - 2 pF of capacitance. A conjugate match to a higher filter impedance is generally less sensitive than matching to 50? . When verifying or adjusting the matching circuit on the prototype circuit board, the LO drive should be injected at the nominal power level (-4 dBm), since the LO level does have an impact on the IF port impedance. There are several networks that can be used to properly match the IF port to the SAW or crystal IF filter. The IF FET bias is applied through the IF output Pin 7, so the matching For additional information and latest specifications, see our website: www.triquint.com 19 TQ5635 Data Sheet 6. Mixer RF Input Matching Network: Vdd Although the TQ5635 can present <2:1 SWR to the SAW filter bypass without a matching circuit, it is still recommended to use an inter-stage network. We have found that the Mixer-Filter interaction discussed earlier can result in degraded OIP3 at L higher LO power levels with no network. Probably more time Cseries 50 will be needed for this phase of the design than for any other, ohms since it involves a process of trial- and-error. IF OUT For example, the evaluation board network was chosen after Cshunt trying all three of the types of Figure 16. For each type, there was found component L and C values which gave >10dB return loss at the RF frequency (LO is turned on for this testing). Then a SAW filter was added in cascade and IP3 was tested. The circuit of Figure 12-C was found to have Figure 14: IF Output Match to 50 ohms superior IP3. The final test of the filter-network-mixer cascade is to connect a network analyzer at the SAW input and measure S11 with the mixer turned on. A 2:1 or better SWR should be seen in the RF pass band of the SAW. At that point, the filter- Vdd network-cascade is ready to be tested with the LNA. bypass RF In 14 2 L2 Z2 IF OUT TQ5635 Mixer A 12 TQ5635 Mixer B 12 TQ5635 Mixer C SAW IF SAW L1 Z1 12 Csaw TQ5635 LNA balanced IF Out Copt RF In 14 2 SAW L1 ? L 2 Z2 ? L2 Z1 TQ5635 LNA 1 ? CSAW 4? FIF (L1 ? L 2) 2 2 RF In Z2 14 2 SAW L1 Z1 Csaw Equivalent Circuit L2 TQ5635 LNA Figure 16: SAW -Mixer Input Networks Figure 15: IF Match to a SAW Filter 20 For additional information and latest specifications, see our website: www.triquint.com TQ5635 Data Sheet 7. Redo GIC Components: A match to a 1000ohm filter will not be as sensitive. The LO After obtaining the optimum network between the SAW and must be turned ON during the test. Mixer RF input, most likely Idd will have changed slightly. Determine a new GIC resistor to bring Idd to the desired value. 9. Test the TQ5635 Cascade: Finally after the LNA and Mixer are properly tuned the device performance as a whole should be measured. 8. Double Check IF Match After any change which affects IF stage current it is importa nt to recheck the IF output match. This is especially true when matching down to 50ohms, since the match is more sensitive. For additional information and latest specifications, see our website: www.triquint.com 21 TQ5635 Data Sheet Package Pinout: GND/LNA Gain GND/LNA Gain Mixer Vdd LNA Out Active Bias 1 GND RF In MXR In LNA GND Mixer LO Vdd GND LNA Bias active bias LNA Vdd LO Buffer IF Amp GND IF Out LO In GIC Pin Descriptions: Pin # Pin Name 1 GND Description and Usage 2 LNA IN 3 GND 4 LNA BIAS An external resistor is connected between this pin and Vdd in order to set the LNA bias current. A value of ~ 2.5 KOhm will give an LNA IDD of ~ 7 mA. 5 LNA VDD LNA supply voltage. An external decoupling/bypass network should be used. 6 GND 7 IF OUT Mixer IF output (~ 500 Ohm, open drain). Connection to Vdd required. External matching required. 8 IF BIAS IF amp FET source. An RF by -passed resistor is placed form this pin to ground in order to set the current in Ground connection. Connect as closely as possible to ground or to package paddle ground. LNA RF input (DC blocked internally). An external match is required which can be chosen for a gain/NF trade-off. Ground connection. Connect as closely as possible to ground or to package paddle ground. Ground connection. Connect as closely as possible to ground or to package paddle ground. this stage. 9 LO IN Mixer LO input (DC blocked internally). Internally matched to ~ 50 Ohms. 10 LO TUNE 11 GND 12 MXR IN Mixer RF input (DC blocked internally). An external matching network is recommended to optimized cascaded IIP3 13 MXR Vdd Supply voltage for the internal bias circuit that sets IF amp current (in conjunction with the external IF BIAS resistor). 14 LNA OUT LNA RF output. It is DC blocked and internally matched to better than 2:1. 15, 16 LNA SOURCE Paddle GND Mixer LO buffer supply voltage. An external bypass capacitor required. An external series inductor is required for peaking LO gain. Ground connection. Connect as closely as possible to ground or to package paddle ground. The source node of the cascade LNA section. A hard ground provides maximum gain and minimum IIP3. A small amount of external inductance will reduce gain and improve IIP3. Ground connection. It is very important to place multiple via holes under the paddle. Provides RF grounding for the part. 22 For additional information and latest specifications, see our website: www.triquint.com TQ5635 Data Sheet Recommended PC board Layout to Accept 16 Pin Lead-less Plastic Package: 0.13 [0.005] 1.10 [0.043] 0.25 [0.010] 0.55 [0.022] A 0.53 [0.021] 1.10 [0.043] DETAIL A 0.50 [0.020] PITCH 4X SIDES 1.10 [0.043] PACKAGE OUTLINE LEADLESS 3x3-16 PCB FOOTPRINT NOTES: 1. ONLY GROUND SIGNAL TRACES ARE ALLOWED DIRECTLY UNDER THE PACKAGE. 2. PRIMARY DIMENSIONS ARE IN MILLIMETERS, ALTERNATE DIMENSIONS ARE IN INCHES. 23 For additional information and latest specifications, see our website: www.triquint.com 23 TQ5635 Data Sheet Package Type: QFN 3x3-16 Lead-less Plastic Package D D2 PIN 1 PIN 1 L E E2 LASER MARK PIN 1 ID e A b JEDEC DESIGNATION A b D D2 e E E2 L DESCRIPTION OVERALL HEIGHT TERMINAL WIDTH PACKAGE LENGTH EXOPSED PAD LENGTH TERMINAL PITCH PACKAGE WIDTH EXPOSED PAD WIDTH TERMINAL LENGTH METRIC 0.90 +/-.10 mm .250 +/-.025 mm 3.00 mm BSC 1.80 +/-.15 mm .50 mm BSC 3.00 mm BSC 1.80 +/-.05 mm .40 +/-.05 mm ENGLISH .035 +/-.004 in .010 +/-.001 in .118 in .071 +/-.006 in .020 in .118 in .071 +/-.002 in .016 +/-.002 in Notes 1 1 1 1 1 1 1 1 Notes: 1. Primary dimensions are in metric millimeters. The English equivalents are calculated and subject to rounding error. Additional Information Additional Information For latest specifications, additional product information, worldwide sales and distribution locations, and information about TriQuint: Web: www.triquint.com Tel: (503) 615-9000 Email: [email protected] Fax: (503) 615-8902 For technical questions and additional information on specific applications: Email: [email protected] The information provided herein is believed to be reliable; TriQuint assumes no liability for inaccuracies or omissions. TriQuint assumes no responsibility for the use of this information, and all such information shall be entirely at the user's own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. TriQuint does not authorize or warrant any TriQuint product for use in life-support devices and/or systems. Copyright © 2001 TriQuint Semiconductor, Inc. All rights reserved. Revision A, February 22, 2001 24 For additional information and latest specifications, see our website: www.triquint.com TQ5635 Data Sheet For latest specifications, additional product information, worldwide sales and distribution locations, and information about TriQuint: Web: www.triquint.com Email: [email protected] Tel: (503) 615-9000 Fax: (503) 615-8902 For technical questions and additional information on specific applications: Email: [email protected] The information provided herein is believed to be reliable; TriQuint assumes no liability for inaccuracies or omissions. TriQuint assumes no responsibility for the use of this information, and all such information shall be entirely at the user's own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. TriQuint does not authorize or warrant any TriQuint product for use in life-support devices and/or systems. Copyright © 2001 TriQuint Semiconductor, Inc. All rights reserved. 25 For additional information and latest specifications, see our website: www.triquint.com 25