WIRELESS COMMUNICATIONS DIVISION GND/LNA Gain LNA Mode TQ5135 N/C LNA Out DATA SHEET logic 1 MXR In GND RF In LNA 3V Cellular CDMA/AMPS LNA/Mixer Receiver IC GND Mixer LO Vdd GND LNA Bias active bias LO In LO Buffer IF Amp Features § Single +2.8V Operation § Adjustable Gain/IP3/Current LNA Vdd GND IF Out GIC § Low Current Operation § Few external components § QFN 3x3mm, 16 Pin Leadless Plastic Package Product Description § High Input IP3 The TQ5135 is an LNA-Downconverter optimized for use in the Korean, Japanese, and US CDMA Bands. The integrated LNA has the gain step function required for CDMA, 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 Cellular band mobile phone. Min Typ Max Units RF Frequency 881.5 MHz Conversion Gain 25.0 dB Noise Figure 1.9 dB 3rd -5.5 dBm 20 mA Input Order Intercept DC supply Current Applications § CDMA mobile Applications Electrical Specifications1 Parameter § Low Noise Figure § Cellular and AMPS mobile applications worldwide § Wireless data applications Note 1. Test Conditions: Vdd=+2.8V, TC=+25C, RF=881.5MHz, RF in =-30dBm LO=966.5MHz, LO input=-4dBm, IF=85MHz For additional information and latest specifications, see our website: www.triquint.com 1 TQ5135 Data Sheet Absolute Maximum Ratings Parameter Storage Temperature Case Temperature w/bias Supply Voltage Symbol Minimum Nominal Maximum Units Tstore -60 25 150 deg. C Tc -40 25 85 deg. C VDD 0 2.8 4 V - - - VDD+0.5V Voltage to any non supply pin 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. Electrical Characteristics Parameter Conditions Min. Typ/Nom Max. Units RF Frequency 832 894 MHz IF Frequency 85 200 MHz LO input level -7 -1 dBm Supply voltage High Gain Mode 22.0 Noise Figure1,4 -7.5 Supply Current 25.0 dB 2.4 -5.5 20.0 dB dBm 23.5 mA LNA Mode = Vsup Conversion Gain 1,3,4 5.5 Noise Figure1,4 Input 3rd Order Intercept1,3,4 7.5 11.0 10.0 Supply Current 2 V 1.9 Input 3rd Order Intercept1,3,4 Note 1. 2.8 LNA Mode = 0 V Conversion Gain 1,3,4 Bypass Mode -4 dB 12.0 12.0 10.0 dB dBm 16.0 mA Test Conditions (devices screened for Conversion Gain, Noise Figure, and IIP3 to the above limits): Vdd = +2.8V, RF = 881.5MHz, LO = 966.5MHz, IF = 85.0MHz, LO input = -4dBm, RF input = -30dBm(High Gain Mode), TC = +25°C, unless otherwise specified. 2. Min./Max. limits are at +25°C case temperature unless otherwise specified. 3. Conversion Gain depends on the values of the two resistors used in the GIC circuit. 4. Data includes image reject filter (Fujitsu P/N: F5CE-881M50-K206-W) insertion loss of 1.6dB For additional information and latest specifications, see our website: www.triquint.com TQ5135 Data Sheet Typical Electrical Characteristics – LNA only: Parameter Conditions RF Frequency Min. Typ/Nom 832 High Gain Mode Conversion Gain Max. Units 894 MHz LNA Mode = 0 V 16 dB 1.5 dB Input 3rd Order Intercept1,3 7.0 dBm Supply Current 9.5 mA Conversion Gain 1,3 -2.5 dB Noise Figure1 2.5 dB Input 3rd Order Intercept1,3 32 dBm Supply Current 0.7 mA Noise 1,3 Figure1 Bypass Mode Note 1. LNA Mode = Vsup Test Conditions: Vdd = +2.8V, RF = 881.5MHz, LO = 966.5MHz, I F= 85MHz, LO input = -4dBm, RF input = -35dBm, TC = 25°C, unless otherwise specified. 2. Min./Max. limits are at +25°C case temperature unless otherwise specified. 3. Conversion Gain depends on the values of the two resistors used in the GIC circuit. Electrical Characteristics – Mixer only: Parameter Conditions RF Frequency IF Frequency Conversion Gain Noise Input Min. Max. Units 832 894 MHz 85 200 MHz 1,3,4 Figure1,4 3rd Order Intercept1,3,4 Supply Current Note 1: Typ/Nom 9.0 dB 8.5 dB 10.0 dBm 10.0 mA Test Conditions: Vdd = +2.8V, RF = 881.5MHz, LO = 966.5MHz, I F= 85MHz, LO input = -4dBm, RF input = -15dBm, TC = 25°C, unless otherwise specified. 2. Min./Max. limits are at +25°C case temperature unless otherwise specified. 3. Conversion Gain depends on the values of the two resistors used in the GIC circuit. 4. Data includes image reject filter (Fujitsu P/N: F5CE-881M50-K206-W) insertion loss of 1.6dB For additional information and latest specifications, see our website: www.triquint.com 3 TQ5135 Data Sheet Typical Test Circuit for CDMA Cellular: Test Conditions (Unless Otherwise Specified): Vdd=+2.8V, Tc=+25C, RF=881MHz, LO=966MHz, IF=85MHz, PRF=-30dBm, PLO=-4dBm B+ AUXin LNA Mode C11 C1 Vdd F1 R1 Lsource GND L1 L5 Alternate Network NC LNA Out RFin LNA Mode GND C6 L4 MXR In RF In C7 GND C8 TQ5135 Vdd VDD IF Bias IF Out R7 GND LNA Bias VDD GND C5 LOin L2 LO In R6 C10 Vdd R9 C9 R12 R16 L3 C14 C13 C15 IFout Bill of Material for TQ5135 LNA/Downconverter Mixer for GIC tuning plots Component Reference Designator Receiver IC Part Number Value TQ5135 Size Manufacturer 3x3mm TriQuint Semiconductor Capacitor C1, C11, C13 0.1uF 0402 Capacitor C5 2.7pF 0402 Capacitor C6 4.7pF 0402 Capacitor C7 22pF 0402 Capacitor C8, C9, C10 1000pF 0402 Capacitor C14 56pF 0402 Capacitor C15 56pF 0402 Inductor L1 15nH 0402 TOKO Inductor L2 18nH 0402 TOKO Inductor L3 100nH 0603 TOKO Inductor L4, L5 12nH 0402 TOKO Resistor R1, R16 3.3O 0402 Resistor R6 20O 0402 Resistor R7 4.7KO 0402 Resistor R9 1.8O 0402 Resistor R12 56O 0402 RF Saw Filter F1 4 For additional information and latest specifications, see our website: www.triquint.com 3x3mm SAWTEK TQ5135 Data Sheet CDMA Cellular Band Typical Performance – High Gain Mode Test Conditions (Unless Otherwise Specified): Vdd=+2.8V, Tc=+25C, RF = 881.5MHz, LO = 966.5MHz, I F= 85MHz Conversion Gain vs Vdd vs Temp 27 27 26 26 Conversion Gain (dB) Conversion Gain (dB) Conversion Gain vs Vdd vs Freq 25 24 23 2_6V 2_7V 22 2_8V 2_9V 21 865 870 875 880 885 890 895 900 25 24 23 -40C 25C 85C 22 21 2.5 RF Freq (MHz) 2.8 2.9 3 Conversion Gain vs LO vs Freq 28 29 Conversion Gain (dB) 27 Conversion Gain (dB) 2.7 Vdd (V) Conversion Gain vs Temp vs Freq 25 23 -40C 25C 85C 21 865 870 875 26 24 22 -4dBm -7dBm 880 885 890 895 900 RF Freq (MHz) Idd vs Vdd vs Temperature Idd vs Temperature vs Frequency 21 20 20 Idd (mA) 21 19 17 2.6 2.7 Vdd (V) 2.8 2.9 19 18 -40C 25C 85C 18 2.5 -1dBm 20 865 870 875 880 885 890 895 900 RF Freq (MHz) 19 Idd (mA) 2.6 3 -40C 25C 85C 17 865 870 875 880 885 890 895 900 RF Freq (MHz) For additional information and latest specifications, see our website: www.triquint.com 5 TQ5135 Data Sheet Input IP3 vs Temp vs Freq Input IP3 vs Vdd vs Temperature 0 -2 -2 IP3 (dBm) IP3 (dBm) -4 -6 -8 -40C 25C 85C 2.6 2.7 2.8 2.9 -6 -8 -12 865 870 875 880 885 890 895 900 RF Freq (MHz) 3 Vdd (V) Noise Figure vs Temp vs Freq -2 3.5 -4 3 -6 -8 -1dBm -4dBm -7dBm -12 865 870 875 880 885 890 895 900 RF Freq (MHz) Noise Figure (dB) IP3 (dBm) Input IP3 vs LO Drive vs Frequency -10 -40C 25C 85C -10 -10 2.5 -4 2.5 2 1.5 1 0 865 870 875 880 885 890 895 900 Frequency (MHz) Noise Figure vs Vdd vs Temp 3.5 Noise Figure (dB) 3 2.5 2 1.5 1 -40C 25C 85C 0.5 0 2.5 6 2.6 2.7 2.8 Vdd (V) -40C 25C 85C 0.5 2.9 3 For additional information and latest specifications, see our website: www.triquint.com TQ5135 Data Sheet CDMA Cellular Band Typical Performance – Low Gain Mode Test Conditions (Unless Otherwise Specified): Vdd=+2.8V, Tc=+25C, RF = 881.5MHz, LO = 966.5MHz, I F= 85MHz Conversion Gain vs Vdd vs Temp 9 9 8 8 Conversion Gain (dB) Conversion Gain (dB) Conversion Gain vs Vdd vs Freq 7 6 2.6V 2.7V 2.8V 2.9V 5 7 6 -40C 25C 85C 5 4 4 865 870 875 880 885 890 895 900 2.5 2.6 2.7 RF Freq (MHz) 8 8 Conversion Gain (dB) Conversion Gain (dB) 10 6 -40C 25C 85C 2 865 870 875 880 885 890 895 900 6 4 -1dBm -4dBm -7dBm 2 865 870 875 880 885 890 895 900 RF Freq (MHz) RF Freq (MHz) Idd vs Temperature vs Frequency 13 13 12 12 11 11 Idd (mA) Idd (mA) Idd vs Vdd vs Temperature 10 -40C 25C 8 2.6 2.7 2.8 Vdd (V) 2.9 10 9 85C 2.5 3 Conversion Gain vs LO vs Freq 10 9 2.9 Vdd (V) Conversion Gain vs Temp vs Freq 4 2.8 3 -40C 25C 85C 8 865 870 875 880 885 890 895 900 RF Freq (MHz) For additional information and latest specifications, see our website: www.triquint.com 7 TQ5135 Data Sheet Input IP3 vs Temp vs Freq Input IP3 vs Vdd vs Temperature 18 15 16 IP3 (dBm) IP3 (dBm) 14 13 12 12 85C 8 865 870 875 880 885 890 895 900 10 2.5 2.6 2.7 2.8 2.9 -40C 25C 85C 10 -40C 25C 11 14 3 RF Freq (MHz) Vdd (V) Noise Figure vs Vdd vs Temperature Input IP3 vs LO Drive vs Frequency 16 13 12 12 10 -1dBm 8 -4dBm -7dBm 6 865 870 875 880 885 890 895 900 Noise Figure (dB) IP3 (dBm) 14 11 10 9 -40C 25C 85C 8 7 2.5 2.6 RF Freq (MHz) Vdd (V) Noise Figure vs Temp vs Frequency Noise Figure (dB) 14 12 10 8 -40C 25C 85C 6 865 870 875 880 885 890 895 900 RF Freq (MHz) 8 2.7 For additional information and latest specifications, see our website: www.triquint.com 2.8 2.9 3 TQ5135 Data Sheet Pinout Description: The TQ5135 is a complete front-end for a low 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 two modes, high gain and bypass. Pin 15 is the input to the gain control logic, which drives the switch FETs. In the high gain mode (pin 15=low), the LNA provides around 17dB of gain. In the bypass mode (pin 15=high) it has a loss of about 2dB. The LNA also provides several ways of setting gain and The IF signal from the mixer is fed to an amplifier. The IF amplifier is an open drain type with output at Pin 7. An 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: intercept in the design phase. The LNA FET source is brought out to Pin 16, where a small value of inductance to ground can be added. The inductor can be discrete or simply a small length of pc board trace. Several dB of adjustment is The TQ5135 does not contain a balanced mixer so Half-IF spur rejection is completely set by the image filter. Thus we do not recommend using an IF that is less than 2.5 times the possible. A bias resistor on pin 4 is used to set the LNA supply current. A nominal value of 2.7kohm is recommended, but it can be increased for lower LNA Idd. Grounding: 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 output connects to the mixer input at Pin 12. The mixer receives its LO via a buffer which amplifies the signal from Pin 9. The drain of buffer transistor is connected to Pin 10 where it is connected to an external LO tuning inductor. GND/LNA Gain With good layout techniques there should not be any stability problems. Poor circuit board design can result in a circuit that oscillates. Good grounding is especially important for the TQ5135 since it uses an outboard LO tuning inductor that provides one more potential ground loop path. One could use the evaluation board as an example of proper layout techniques. It is important to position the LO tuning, GIC, and IF matching LNA Mode components as close to the chip as possible. If the components are far enough away they and their corresponding pc board traces can act as quarter wave N/C LNA Out logic 1 MXR In GND RF In image filter. LNA GND resonators in the 5-10Ghz region. If both the IF and the LO paths to ground resonate at the same frequency, oscillation can result. Mixer LO Vdd GND LNA Bias active bias LNA Vdd LO Buffer IF Amp GND IF Out GIC Figure 1. TQ5135 Block diagram LO In It is most important that the ground on the GIC bypass cap, 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). Also, improving the ground at the LO tuning inductor bypass cap will increase circuit Q. Thus mixer drive is improved with a resultant higher IP3. Improved ground here means minimal inductance between the chip ground pins and the other ground return points. For additional information and latest specifications, see our website: www.triquint.com 9 GND RF In TQ5135 GND VDD IF Out IF Bias GND VDD to the IF where it is amplified by the IF output FET. The quiescent current in the IF amplifier is set by the GIC network. Both the filter and the mixer terminate the RF signal with MXR In GND LNA Bias image filter, and mixer. The RF signal is amplified by the LNA, passes through the image filter, and is converted down VDD GND LNA Out TQ5135 Data Sheet 50ohms. LO In However, the situation is much different with the LO signal. At the LO frequency the image filter looks like a short circuit. Vdd 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 which is fed into the IF amplifier and changes the quiescent current. Depending on the phase of the reflected LO, the IF stage current may be higher or lower. Figure 2. Critical signal Paths Mixer – Filter Interaction: Before attempting a new TQ5135 application, it is important to understand the nonlinear interaction between the image filter and the mixer. The device IP3 is a strong function of this interaction. For this reason it is helpful to consider the filter and mixer as one nonlinear block. Figure 3 shows a much simplified block diagram of the LNA, The DC offset also affects the passive mixer FET to some degree as well. It has been found empirically that varying the delay between the filter and mixer can have positive or negative consequences on IP3, CG, and NF. It is for this reason that an LC network is useful between the SAW and mixer input, even though the mixer input can have an adequate match at the RF frequency without any external components. 25-100 ohms at RFshort circuit at LO LO Leakage LNA Out RF in 2 LNA Portion of TQ5135 Mixer Portion of TQ5135 Mixer IF Output FET 12 14 IF Output 7 Idd + Idd Offset Mixer in band pass IF + DC Offset LO Leakage ( φ ) LO 9 to GIC 8 (LO Leakage( φ)+ LO) = DC Offset at Mixer IF Output Figure 3. Non-linear filter-Mixer Interaction 10 For additional information and latest specifications, see our website: www.triquint.com TQ5135 Data Sheet LNA S-Parameters : S-Parameters for the TQ5135 LNA taken in both the high gain and low gain modes. We have not included noise parameters since for this device Gamma-Opt is very close to the conjugate match. Figure 4: LNA S11 in HG Mode Figure 6: LNA S21 in HG Mode Figure 5: LNA S12 in HG Mode Figure 7: LNA S22 in HG Mode For additional information and latest specifications, see our website: www.triquint.com 11 TQ5135 Data Sheet 12 Figure 8: LNA S11 in LG Mode Figure 10: LNA S21 in LG Mode Figure 9: LNA S12 in LG Mode Figure 11: LNA S22 in LG Mode For additional information and latest specifications, see our website: www.triquint.com TQ5135 Data Sheet SUGGESTED STEPS FOR TQ5135 TUNING: The following order of steps is recommended for applying the 1. Determine LNA Bias Resistor Value and Source TQ5135. They are described in detail in the following sections: Inductor Value Lay out board consistent with the grounding guidelines at the beginning of this note. See section 1 regarding LNA source inductor. 1. Determine the LNA bias resistor value and source inductor value 2. Determine the LNA input matching network component values. Test the LNA by itself. 3. For the mixer, experimentally determine proper LO tuning For most designs we recommend an LNA bias resistor of 2.7K ohms. All of the datasheet specs assume that value of resistor. However, if LNA Idd <15mA is desired, then the resistor can be made larger. Refer to Figure 12 for graphs of LNA performance vs. bias resistor. Please keep in mind that there are implications of reduced LNA bias that are not reflected in IP3. For example, the LNA is 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. 4. Determine a tentative GIC network. It will have to be finetuned later, since the image filter interaction will affect device current. 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. 6. Experimentally determine a tentative mixer RF Input match. LO is turned ON. Test the filter-mixer cascade. Verify that the device has adequate IP3. If not, another RF Input matching topology can be tried. 7. Fine tune GIC components for needed Idd. LO is turned ON. 8. Check IF match to see if it still is adequate. LO is turned ON. 9. Test the device as a whole- LNA, filter, mixer 5135LNA NF, Gain, IIP3 and Idd vs bias resistor dB Idd (mA) 18 23.00 16 21.00 14 19.00 NF Gain IIP3 Idd 12 10 17.00 15.00 8 13.00 6 11.00 4 9.00 2 7.00 0 1.1 1.5 2.2 2.7 3.3 4.7 6.8 8.2 5.00 10 Bias resistor (kOhms) Figure 12: Gain, IIP3, Idd, and NF as a Function of Rbias For additional information and latest specifications, see our website: www.triquint.com 13 TQ5135 Data Sheet A small amount of inductance is needed from pin 16 to ground for proper degeneration of the LNA input dielectric FR4 board, then it is likely that the component values on the evaluation board can be stage. Too much inductance at this point will degrade LNA gain, while too little inductance will degrade NF at the conjugate match. Because of stray inductance on used for a starting point. Alternately, a network can be synthesized from the S-parameter values at the end of this note. the application board layout, it is difficult to give a precise value in nH. Thus we recommend during the prototype stage to use one of the copper patterns in 3. LO Buffer Tuning Figure 13. The drain of the LO buffer is brought out to pin 10 A short can be placed across the pattern and its position varied until the desired gain is met. Then the unused copper can be removed for the final product. where it is fed DC bias via an inductor. The inductor resonates with the internal and external parasitic capacitance associated with that pin. For maximum performance the resonance must be at or near the 2. Determine the LNA Matching Network desired LO frequency. Figure 14 shows a properly tuned LO buffer. Notice that the LO frequency range of interest is to the left of the peak. We recommend GND MXR In GND GND RF In TQ5135 For additional information and latest specifications, see our website: www.triquint.com IF Bias LNA Bias IF Out IF Bias IF Out LO In VDD GND VDD VDD GND VDD GND Figure 13: LNA Source Inductor Realization 14 MXR In TQ5135 GND LNA Bias NC input matches. GND RF In performance versus frequency. We have also found empirically that tuning the LO slightly higher in frequency results in much better LO input and RF NC LNA Out GND LNA Mode GND once a match to 50ohms is attained, only a slight adjustment to the L and C values may be needed for optimum noise figure. If the design uses 5-8mil that the LO is tuned slightly higher in frequency, so that the desired band is on the lower, more gradual side of the slope. Thus there is less change in LNA Out simpler than designing with discrete transistors. The TQ5135 LNA was designed so that the optimum noise match is very close to the conjugate match. Thus LNA Mode Matching network design for the TQ5135 LNA is much LO In TQ5135 Data Sheet Figure 14: Suggested LO Tuning Response A first approximation to the needed inductor can be found by the following equation: 1 L = ---------------- - 1nH where C=1.5pF 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 resistor of 3.3ohm to 20ohm has been found to work well for Figure 14 shows the recommended test setup for tuning the TQ5135 LO buffer. A network analyzer is set to the center of the LO band +/- 300Mhz, with an output power of –4dBm. It is important to set the frequency range to be quite a bit wider than the LO band, so that the shape of the tuning curve can be seen. A two port calibration is performed and the analyzer is set to monitor S21. Port 1 of the analyzer is connected to the LO port of the TQ5135, 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. this purpose (R2). For additional information and latest specifications, see our website: www.triquint.com 15 GND RF In additional IP3 performance may be gained by increasing the quiescent current, in practice it makes no sense to increase Idd beyond that which provides maximum input intercept. At VDD MXR In GND TQ5135 VDD IF Out IF Bias VDD GND GND LNA Bias since there is always some package and bond wire inductance back to the die. Furthermore, although some COAXIAL PROBE VDD GND LNA Out TQ5135 Data Sheet 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 TQ5135 (Figure 16). The first uses a small resistor (1.0 to 5 ohms) in series with a bypass capacitor to set the AC gain. The IF stage current is then set by the larger resistor (40 to 80 PORT 1 MEASURE S21 NETWORK ANALYZER ohms) that connects directly from the GIC pin to ground. The small degeneration resistor lowers the IF stage gain. Figure 15: LO Tuning Test Setup The second scheme, which is recommended for maximum 4. GIC Network Design The GIC pin on the TQ5135 is connected internally to the source of the IF output stage. By adding one or two resistors and a capacitor to this pin, it is possible to vary both the IF stage AC gain, and the IF stage quiescent current. However, there is a limit to the amount of gain increase that is possible, GIC PIN gain, uses a resistor in parallel with capacitor. The resistor sets the DC current, while the capacitor bypasses it at the IF frequency. For highest gain, place the capacitor as close to Pin 7 as possible. Try to avoid capacitors which are selfresonant at the IF frequency. Here is an approximate equation for Rgic as a function of IF 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 16: GIC Pin Networks 16 For additional information and latest specifications, see our website: www.triquint.com Chip GND Zc bypass at IF Freq TQ5135 Data Sheet 5135 Mixer NF, Gain, IIP3 and Idd vs GIC resistor dB Idd (mA) 12 13 12 11 11 10 10 9 9 8 NF Gain IIP3 Idd 8 7 7 6 6 5 5 4 33 39 47 56 GIC resistor (Ohms) 68 82 Figure 17: Mixer Performance as a Function of Rgic 5. IF Match Design The Mixer IF output (Pin 7) is an "open-drain" configuration, allowing for flexibility in efficient matching to various filter types and at various IF frequencies. An optimum lumpedelement-matching network must be designed for maximum TQ5135 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 impedance from 500 -1000Ω with 1 - 2 pF of capacitance. A conjugate match to a higher filter impedance is generally less sensitive than matching to 50Ω . 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 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 circuit topology must contain either a RF choke or shunt inductor. For purposes of 50 ohm evaluation, the shunt L, series C, shunt C circuit shown in Figure 18 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 improve the return loss and to reduce the LO leakage. The circuit is used on our evaluation board. For matching into a filter, the circuit of Figure 19 works well. The network provides the needed impedance transformation 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 much higher than the IF frequency, then Copt can be added to lower it. Please note that because of parasitic capacitance and the discrete values of commercial inductors, the formulas of Figure 15 only serve as a starting point for experimentation. In order to minimize loss, any inductors used should have high Q. Typically 0805 size inductors perform better than the 0603 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 TQ5135. 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. For additional information and latest specifications, see our website: www.triquint.com 17 TQ5135 Data Sheet 6. Mixer RF Input Matching Network: Vdd Although the TQ5135 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 Cseries 50 ohms IF OUT higher LO power levels with no network. Probably more time will be needed for this phase of the design than for any other, since it involves a process of trial-and-error. It has been found experimentally that maximum IP3 for the TQ5135 evaluation board occurs when the mixer input sees a high impedance at the LO frequency. Since the SAW filter looks like a short circuit at the LO frequency, the network Cshunt simply needs to add the correct amount of delay to rotate the reflection coefficient around the Smith chart to near “open circuit”. Either the circuit of Figure 20-A or 20-B will Figure 18: IF Output Match to 50 ohms accomplish this. On the evaluation board, we have found network values that will accomplish this with no degradation at the RF frequency. Depending upon board layout and LO buffer tuning, it is possible for the mixer RF input to have a poor match. In that case, the circuit of Figure 20-C should be used. The matching Vdd bypass and delay can be accomplished with two components. L2 Z2 IF OUT IF SAW L1 Z1 Csaw Copt balanced IF Out In either case, it is important that the SAW filter see a 2:1 SWR at the RF frequencies. Otherwise there will be excessive ripple across the band. 14 RF In 2 Z2 − L2 Z1 L1 ≅ L2 1 ≤CSAW 4π FIF ( L1 + L2) 2 12 TQ5135 Mixer A 12 TQ5135 Mixer B TQ5135 Mixer C SAW 2 TQ5135 LNA Z2 RF In 14 2 L1 Z1 Csaw SAW Equivalent Circuit TQ5135 LNA L2 RF In 14 2 Figure 19: IF Match to a SAW Filter 12 SAW TQ5135 LNA Figure 20: SAW-Mixer Input Networks 18 For additional information and latest specifications, see our website: www.triquint.com TQ5135 Data Sheet 7. Redo GIC Components: 9. Test the TQ5135 Cascade: After obtaining the optimum network between the SAW and Finally after the LNA and Mixer are properly tuned the device Mixer RF input, most likely Idd will have changed slightly. Determine a new GIC resistor to bring Idd to the desired value. performance as a whole should be measured. AMPS Mode Application with External Switching: 8. Double Check IF Match After any change which affects IF stage current it is important to recheck the IF output match. This is especially true when matching down to 50ohms, since the match is more sensitive. A match to a 1000ohm filter will not be as sensitive. The LO must be turned ON during the test. The TQ5135 is a single IF output low-band CDMA receiver. Because it uses a straightforward design it achieves very high performance for a device drawing 20-25mA. However, it is possible to add dual IF output (e.g. CDMA/AMPS) capability externally to the device using an inexpensive switch which allows switching between two different IF filters. More information can be found from separate application note. For additional information and latest specifications, see our website: www.triquint.com 19 TQ5135 Data Sheet Package Pinout: GND/LNA Gain LNA Mode N/C LNA Out logic 1 MXR In GND RF 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 LNA GND2 2 LNA IN 3 Not Connected 4 LNA BIAS Connected to external LNA bias resistor. 5 LNA VDD Connected to external LNA supply voltage and RF bypass capacitor. RF bypass capacitor should be as close as possible to IC. 6 LNA GND1 Ground connection. Connect as closely as possible to ground or to package paddle ground. 7 IF 8 IF BIAS 9 LO IN 10 LO VDD Connected to external series LC network for LO drain tuning. Network should be as close to IC as possible with good grounding of capacitor. 11 LO GND Ground connection. Connect as closely as possible to ground or to package paddle ground. 12 MXR IN Connected to external mixer matching network. Connect image reject filter as closely to this pin as possible (~0.1in). Interface is DC blocked. 13 Not Connected 14 LNA OUT 15 LNA MODE 16 LNA SOURCE Paddle GND 20 Description and Usage Ground connection. Connect as closely as possible to ground or to package paddle ground. Connected to external RF input matching network. Interface is DC blocked. Open connection. No connection is necessary. Connected to external IF matching network and IF supply voltage. Connected to external IF source degeneration resistor and RF bypass capacitor. Connected to LO input signal. Interface is DC blocked. Open connection. No connection is necessary. Connected to external image reject filter. Interface is DC blocked. Connected to external mode control signal. Connected to LNA’s external source degeneration inductance (realized with PCB trace). Inductance can vary between 0 and 1 nH. Ground connection. It is very important to place multiple via holes under the paddle. Provides RF grounding for the part. For additional information and latest specifications, see our website: www.triquint.com TQ5135 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] 0.53 [0.021] A 1.10 [0.043] DETAIL A 0.50 [0.020] PITCH 4X SIDES 1.10 [0.043] PACKAGE OUTLINE LEAD-LESS 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. For additional information and latest specifications, see our website: www.triquint.com 25 TQ5135 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 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 22 For additional information and latest specifications, see our website: www.triquint.com