WIRELESS COMMUNICATIONS DIVISION TQ5631 GND RF IN GND VDD IF out VDD DATA SHEET 3V PCS Band CDMA RFA/Mixer IC LO IN GIC Features Small size: SOT23-8 Single 3V operation Low-current operation Product Description Gain Select The TQ5631 is a 3V, RFAmplifier/Mixer IC designed specifically for PCS band CDMA applications. It’s RF performance meets the requirements of products designed to the IS-95 standards. The TQ5631 is designed to be used with the TQ3631 (CDMA LNA) which provides a complete CDMA receiver for 1900MHz phones. High IP3 performance The RFA/Mixer incorporates on-chip switches which determine gain select states. When used with the TQ3631 (CDMA LNA), four gain steps are available. The RF input port is internally matched to 50 Ω, greatly simplifying the design and keeping the number of external components to a minimum. The TQ5631 achieves good RF performance with low current consumption, supporting long standby times in portable applications. Coupled with the very small SOT23-8 package, the part is ideally suited for PCS band mobile phones. Few external components Applications IS-95 CDMA Mobile Phones Electrical Specifications1 Parameter Min Typ Max Units Frequency 1960 MHz Gain 15.0 dB Noise Figure 5.7 dB 3rd 1.0 dBm 20.0 mA Input Order Intercept DC supply Current Note 1: Test Conditions: Vdd=2.8V, RF=1960MHz, LO=1750MHz, IF=210MHz, Ta=25C, LO input –4dBm, CDMA High Gain state. For additional information and latest specifications, see our website: www.triquint.com 1 TQ5631 Data Sheet Electrical Characteristics Parameter Conditions Min. Typ/Nom Max. Units RF Frequency PCS band 1800 1960 2200 MHz IF Frequency 100 210 300 MHz LO Frequency 1600 1750 2300 MHz 12.2 15.0 CDMA Mode-High Gain Gain Noise Figure 5.7 Input IP3 -1.0 Supply Current dB 6.8 1.0 20.0 dB dBm 25.5 mA CDMA Mode-High Gain Low Linearity Gain 17.0 21.0 dB Noise Figure 5.3 dB Input IP3 -3.0 dBm Supply Current 20.0 mA 3.0 dB Noise Figure 12.0 dB Input IP3 18.0 dBm Supply Current 15.0 mA 8.0 dB Noise Figure 10.0 dB Input IP3 13.5 dBm Supply Current 15.0 mA CDMA Mode-Mid Gain Gain 1.0 CDMA Mode-Low Gain Gain 6.2 Supply Voltage 2.7 2.8 Note 1: Test Conditions: Vdd=2.8V, RF=1960MHz, LO=1750MHz, IF=210MHz, TC = 25° C, LO input –4dBm, unless otherwise specified. Note 2: Min/Max limits are at +25°C case temperature, unless otherwise specified. Absolute Maximum Ratings Parameter Value Units DC Power Supply 5.0 V Power Dissipation 500 mW Operating Temperature -30 to 85 C Storage Temperature -60 to 150 C Signal level on inputs/outputs +20 dBm Voltage to any non supply pin +0.3 V 2 For additional information and latest specifications, see our website: www.triquint.com 2.9 V TQ5631 Data Sheet Typical Performance, Note:HG=High Gain, LL=High Gain Low Linearity, LG=Low Gain Test Conditions, unless otherwise specified: Vdd=2.8V, Ta=25C, RF=1960MHz, LO=1750MHz, IF=210MHz, LO input=-4dBm , Conversion Gain vs. Freq. IDD vs. Freq. 25.00 21.00 20.00 19.00 15.00 IDD (mA) Gain (dB) 20.00 10.00 0.00 1930 1940 1950 1960 1970 Freq. (MHz) 1980 LG Mode HG Mode LL Mode 17.00 16.00 15.00 LG Mode HG Mode LL Mode 5.00 18.00 14.00 13.00 1930 1990 1940 1990 20.00 LG Mode HG Mode LL Mode 6.00 Gain (dB) IIP3 (dBm) 1980 25.00 11.00 1.00 15.00 10.00 LG Mode HG Mode LL Mode 5.00 0.00 1940 1950 1960 1970 Freq. (MHz) 1980 1990 -30 -15 0 10.00 9.00 IIP3 (dBm) LG Mode HG Mode LL Mode 7.00 6.00 5.00 1940 1960 Freq. (MHz) 30 45 60 75 90 IIP3 vs. Temp. 11.00 8.00 15 Temp. (C) Noise Figure vs. Freq. NF (dB) 1970 Conversion Gain vs. Temp. 16.00 4.00 1920 1960 Freq. (MHz) IIP3 vs. Freq. -4.00 1930 1950 1980 2000 15.00 13.00 11.00 9.00 7.00 5.00 3.00 1.00 -1.00 -3.00 -5.00 LG Mode HG Mode LL Mode -30 -15 0 15 30 45 Temp. (C) For additional information and latest specifications, see our website: www.triquint.com 60 75 90 3 TQ5631 Data Sheet Noise Figure vs. Temp. 20.00 15.00 LG Mode HG Mode LL Mode 10.00 IIP3 (dBm) NF (dB) 12.00 11.00 10.00 9.00 8.00 7.00 6.00 5.00 4.00 3.00 2.00 IIP3 vs. LO Power 5.00 LG Mode HG Mode LL Mode 0.00 -5.00 -30 -15 0 15 30 45 Temp. (C) 60 75 -7 90 24.00 10.00 22.00 9.00 8.00 NF (dB) LG Mode HG Mode LL Mode 18.00 16.00 LG Mode HG Mode LL Mode 7.00 6.00 14.00 5.00 12.00 4.00 -30 -15 0 15 30 45 60 75 90 -7 -5 Temp. (C) 20.00 21.00 15.00 19.00 IDD (mA) 25.00 10.00 LG Mode HG Mode LL Mode 0.00 -1 IDD vs. LO Power 23.00 5.00 -3 LO Power (dBm) Conversion Gain vs. LO Power Gain (dB) -1 Noise Figure vs. LO Power 20.00 LG Mode HG Mode LL Mode 17.00 15.00 13.00 -7 4 -3 LO Power (dBm) IDD vs. Temp. IDD (mA) -5 -5 -3 LO Power (dBm) -1 -7 For additional information and latest specifications, see our website: www.triquint.com -5 -3 LO Power (dBm) -1 TQ5631 Data Sheet Conversion Gain vs. VDD IDD vs. VDD 24.00 23.00 21.00 22.00 20.00 17.00 IDD (mA) Gain (dB) 19.00 15.00 13.00 LG Mode HG Mode LL Mode 11.00 LG Mode HG Mode LL Mode 18.00 16.00 14.00 9.00 12.00 7.00 2.7 2.8 2.9 3 3.1 3.2 2.7 2.8 2.9 3 3.1 3.2 VDD (V) VDD (V) IIP3 (dB) IIP3 vs. VDD 16.00 14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 -2.00 -4.00 LG Mode HG Mode LL Mode 2.7 2.8 2.9 3 3.1 3.2 VDD (V) Noise Figure vs. VDD 10.00 9.00 NF (dB) 8.00 LG Mode HG Mode LL Mode 7.00 6.00 5.00 4.00 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 VDD (V) For additional information and latest specifications, see our website: www.triquint.com 5 TQ5631 Data Sheet Application/Test Circuit Control 2 RF AMP Gain R9 Select RF IN GND L2 VDD MXR VDD GND C19 R10 C11 IF Out C13 IF out VDD VDD L3 L4 LO IN GIC C12 R7 R8 RF input C10 C20 VDD MXR C15 LO IN IF AMP Gain Select Control 3 C14 Bill of Material for TQ5631 RF AMP/Mixer Component Reference Designator Part Number Receiver IC U1 TQ5631 Capacitor C11 22pF 0402 Capacitor C12, C14, C15, C19 1000pF 0402 Capacitor C13 12pF 0402 Capacitor C10 1.5pF 0402 Capacitor C20 68pF 0402 Resistor R8 27Ω 0402 Resistor R7, R9 5.1KΩ 0402 Resistor R10 20Ω 0402 Inductor L2 2.7nH 0402 Panasonic Inductor L3 4.7nH 0402 Panasonic Inductor L4 56nH 0603 Panasonic Filter U2 6 Value L2XB For additional information and latest specifications, see our website: www.triquint.com Size Manufacturer SOT23-8 TriQuint Semiconductor Fijitsu TQ5631 Data Sheet Logic truth table and logic control functions TQ5631 Product Description Simplified theory of operation TABLE 1 TRUTH TABLE CONTROL LINES The TQ5631 contains an RF amp, mixer, IF amp, and RF switches. Pin count is reduced by doubling the function of several pins, where dc control bias and RF signal are present at the same time. (Figure 1) In the low gain modes, the RF amp is disabled and the the input signal is routed directly to the mixer. In the high gain modes, a cascode amp is switched in before the mixer. Control for this function is made via a dc signal on the RF input pin 8. A number of switches are used internally to eliminate any parasitic signal paths. The IF amp gain can be stepped as well via a control line at pin 5. The general IF amp gain and current draw can be set using external components at the GIC pin 4. The TQ5631 uses an off chip inductor with a bypass capacitor at pin 6 for tuning the LO buffer. Although the device can be connected directly to 50Ω at the RF input, a better match is obtained by using a small series inductor and shunt capacitor at the RF input . Receiver RFA Gain IFA Gain Mode Select Select C2 C3 IFA 0 0 HG CDMA Idd HG CDMA HGLL 0 1 HG Low Idd HG CDMA MG 1 0 HG CDMA Idd Bypassed LG CDMA LG 1 1 Bypassed Bypassed HG LG HG HG=High Gain; HGLL=High Gain Low Linearity; MG=Mid Gain; LG=Low Gain TABLE 1 When used in conjunction with the TQ3631, the TQ5631 down convert mixer can be set to a variety of different gain states. This allows the receiver (LNA + downconvert mixer) to operate with a wide dynamic range, while optimizing current draw and overall receiver performance. Two external control lines set the LNA + downconverter into any one of the four states, described below. a) CDMA Low Gain Mode: This mode is selected in very high signal environment. The current draw in this case is 16mA for the receive chain. b) CDMA High Gain Mode: This mode is selected in very weak signal environment. The receiver is in it’s maximum sensitivity. c) CDMA High Gain Low Linearity Mode: This mode is selected when the phone is in standby mode. The phone power amplifier will be off in this state, removing the possibility of self jamming. RF IN RF IN 1 8 2 7 3 6 4 5 VDD LO TUNE IF GIC d) CDMA Mid Gain Mode. This mode is selected in a medium signal strength environment. VDD GND IF OUT Mixer State RFA CDMA HG RFA GAIN SELECT, C2 GND LNA State VDD DOWNCONVERTER APPLICATION HINTS: LO/C3 IF GAIN SELECT, C3 VDD LO IN GIC ADJUST Printed Circuit Board Layout guidelines for stability With good layout practices the circuit will be stable. However, FIGURE 3 TQ5631 SIMPLIFIED CIRCUIT poor layout may lead to oscillation problems. Good grounding is especially important for the TQ5631 since it uses an off-chip LO For additional information and latest specifications, see our website: www.triquint.com 7 TQ5631 Data Sheet tuning inductor which provides a potential ground loop path. One could use the evaluation board as an example of proper from the die out to the pin which much be subtracted off of the needed inductance value. layout techniques. It is important to position the LO tuning and the GIC components as close to the chip as possible. If the components are placed RF IN GND 1 8 2 7 3 6 4 5 COAXIAL PROBE VDD too far from the chip the PC board traces can act as quarter wave resonators in the 5-10GHz region. If both the GIC and the LO paths to ground resonate at the same frequency, oscillation VDD GND LO TUNE IF GIC can result, especially if Q is very high. LO/C3 IF GAIN SELECT, C3 It is most important that the ground on the GIC bypass cap, the LO tuning bypass capacitor, and the IF shunt cap return back to chip pins 1 and 2 with minimal inductance. This requires that LO IN ground returns utilize vias at a number of locations. PORT 1 Solid grounding of the LO tuning inductor and bypass capacitor will result in higher tuning circuit Q. The higher the Q, the MEASURE S21 greater the LO drive to the mixer will be and IIP3 performance will also improve with higher Q. NETWORK ANALYZER LO Buffer Tuning Figure 2 LO Tuning Setup Because of the broadband input match of the L0 buffer amplifier, The inductor is selected that would resonate with the total thermal and induced noise at other frequencies can be amplified and injected directly into the L0 port of the mixer. Noise at the IF frequency, and at L0 +/- IF will be downconverted and emerge at the IF port, degrading the downconverter noise figure. For maximum flexibility the high band TQ5631 device has the output node of the L0 buffer amplifier brought out to Pin 6. By connecting an external inductor between the pin and Vdd, LO tuning can be varied. This inductor is selected to resonate with internal capacitance at the L0 frequency in order to roll off out- capacitance at the L0 frequency using the following equation: 1 L = ---------------- - 1.3nH C (2*pi*F)2 To fine tune the LO, two methods have been proven to work well: a) of-band gain and improve noise performance. This approach allows selectivity in the L0 buffer amplifier along with the ability to use the TQ5631 with multiple IF’s. Calculation of Nominal L Value The proper inductor value must be determined during the design phase. The internal capacitance at Pin 6 is approximately 1.6 pF. Stray capacitance on the board surrounding Pin 6 will add to the internal capacitance, so the nominal value of inductance can be calculated, but must be confirmed with measurements on a board approximating the final layout (see Figure 2). Additionally, there is already approximately 1.3nH of inductance 8 where C=1.6pF Select the inductance (next standard value) which is higher than the calculated value derived from the equation above. Then select a bypass capacitor that forms a resonant circuit with the inductor. The bypass capacitor can be used to fine tune the resonant frequency. b) The second method relies on moving the bypass capacitor relative to the tuning inductor. This varies the amount of inductance in the circuit and provides a means to fine tune the LO. This method is utilized on the test boards. For additional information and latest specifications, see our website: www.triquint.com TQ5631 Data Sheet Verification of Proper LO Buffer Amp Tuning Half IF Spur Rejection Considerations Using a Network Analyzer Because the TQ5631 does not contain a balanced mixer, Half IF Connect port 1 to the L0 input (Pin 5) of the TQ5631 with the source power set to deliver -4 dBm. Connect the coaxial probe to Port 2 and place the probe tip approximately 0.1 inch away from the inductor. The magnitude of S21 represents the L0 buffer frequency response (figure 3). The test can be done in any of the CDMA modes, but both the rf and IF ports should be terminated to 50 ohms. 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 bandwidth of the image filter. Downconverter IF Match Design The Mixer IF output (pin 3) is an "open-drain" configuration, allowing for flexibility in efficient matching to various filter types and at various IF frequencies. An optimum lumped-element matching network must be designed for maximum power gain and output third order intercept. When designing the IF output matching circuit, one has to consider the output impedance (pin 3) of the IF Amplifier. It will vary somewhat depending on the quiescent current, which is set with the GIC pin. The IF frequency can be tuned from 100 to 300 MHz by varying component values of the IF output matching circuit. The IF output pin also provides the DC bias for the output FET’s. Figure 3 LO Buffer Response In the user's application, the IF output is most commonly The absolute value isn't important, since it depends on the from 300 -1000Ω with 1 - 2 pF of capacitance. A conjugate probe's distance from the pin (it is usually around -30 dB), but the peak of the response should be centered in the slightly to the right of the L0 frequency band center, in this case 1750Mhz. match to a higher filter impedance is generally less sensitive Increasing the inductance will lower the center frequency, and vice versa. Try to keep the probe away from the LO input as it will interfere with the measurement. We have found experimentally that optimum mixer performance connected to a narrowband SAW or crystal filter with impedance 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 impedance. Suggested Matching Networks is achieved when the LO is tuned slightly higher than the band center. Additionally, since the curve is much steeper on the high-side of the LO tuning curve, it is best to tune the device to a There are several networks that can be used to properly match the IF port to the SAW or crystal IF filter. The IF FET current is applied through the IF output pin 3, so the matching circuit slightly higher frequency to ensure that the application is never operated in that region of the curve. Small variations in the application circuit due to inductor tolerances and pc board trace topology must contain either an RF choke or shunt inductor as shown in Figure 4. capacitance will then have less affect on the circuit. shown below 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. Lower than expected IIP3 is the major symptom of improper LO tuning in an application. The internal passive mixer FET needs some minimum LO voltage at its gate in order to achieve satisfactory IP3, which does not occur if the LO is untuned. For purposes of evaluation, the shunt L, series C, shunt C circuit The shunt C, in particular can be used to improve the return loss and to reduce the LO leakage. Generally the shunt C should be equal or larger than the series C. Furthermore, for best stability, For additional information and latest specifications, see our website: www.triquint.com 9 TQ5631 Data Sheet the ground end of the shunt cap should be as close to the chip ground as is possible. Vdd bypass Chip GND GIC PIN Chip GND GIC PIN 0 to 5 ohms L 0 to 5 ohms AC degen AC degen 20 to 60 ohms Cseries sets IF current 50 ohms IF OUT 20 to 60 ohms Zc bypass at IF Freq Zc bypass at IF Freq sets IF current Cshunt Minimize Board Ground Return Inductance Minimize Board Ground Return Inductance Figure 4 IF Output Match Figure 5 GIC Pin Networks GIC Component Selection The GIC pin on the TQ5631 is connected internally to the source of the IF output stage. By adding 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, since there always exists some package and bond wire inductance back to the die. Furthermore, although some 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 some point IP3 is limited by the mixer FET, and no further increase in input intercept can be obtained by adjusting the IF stage. There are two GIC schemes that are recommended for the CDMA devices (Figure 5). The first uses a small resistor in series with a larger bypassed resistor. The AC gain is set by the unbypassed resistor, while the DC IF current is then set by the The Image Filter to Mixer RF input Path We recommend evaluating the CDMA downconverter by considering it and the image filter as a block, since there is a very complicated non-linear interaction between the mixer and image filter. Especially in the LG and MG receiver modes, some LO energy leaks out through the RF input, reflects off the image filter, and then returns back into the mixer (Figure 6). The reflection at the filter occurs because most SAW and dielectric filters look like a short circuit outside of the passband. Depending on the phase of the reflected signal, noise figure, gain, and IP3 can be negatively affected. Thus system simulation can be inaccurate if the downconverter and filter are treated separately. LNA in Bypass Mode LO Leakage Mixer sum of the two resistors. IF band pass The second scheme, which is recommended for the high band device, uses a resistor in parallel with a series combination of LO Leakage + φ LO resistor and capacitor. The first resistor sets the DC current, while the equivalent parallel resistance sets the AC gain. The presence of a resistor directly from the GIC pin to ground tends Figure 6 Mixer-Filter Interaction to dampen the Q of any resonance in the 5-10ghz range which might be formed by the GIC circuitry. The issue also raises a dilemma with regard to the specification of SSB noise figure. An image filter is needed for measurement; yet how does one go about specifying the SSB noise figure (CG 10 For additional information and latest specifications, see our website: www.triquint.com TQ5631 Data Sheet and IIP3 as well) of the downconverter alone, realizing that it depends somewhat upon the type of image filter used and the delay between it and the mixer? The most pragmatic approach measures the NF, CG, and IIP3 with the filter in place. The downconverter to filter distance(in pS) is set to be similar to that which would be used in the end application. Then filter I.L. is simply subtracted off of the system noise figure in order to arrive at the downconverter NF. Similarly, the filter I.L. is subtracted off of the IIP3 and added to the CG in order to arrive at those numbers. Use correct RF input power levels for accurate test results Because the CDMA devices have a number of gain states, it important to make sure that IP3 measurements are not taken in a state of compression. Additionally, using too low of a power puts the IMD products too close to the noise floor for accurate results. Figure 7 shows the automated test setup that is used for evaluation. Table 2 lists the RF input powers that we are using to evaluate the devices, which has proved to be effective for automated measurement. For bench measurement, it is possible to use much lower input powers, since no hardware routines are needed for peak searching. RF Input Power (dBm) Mode Downconverter plus Filter CDMA HGLL -20 CDMA HG -20 CDMA MG -5 CDMA LG -10 Table 2 Suggested RF Input Test Levels For additional information and latest specifications, see our website: www.triquint.com 11 TQ5631 Data Sheet Package Pinout GND RF IN GND VDD IF out VDD GIC LO IN Pin Descriptions Pin Name Pin # GND 1 Ground GND 2 Ground IF OUT 3 IF Output and IF Vdd GIC 4 Off chip tuning for gain/IP3/current LO IN 5 LO Input, and Control 3 input VDD 6 LO Buffer Vdd VDD 7 Mixer Vdd RF IN 8 RF input, and Control 2 input 12 Description and Usage For additional information and latest specifications, see our website: www.triquint.com TQ5631 Data Sheet Package Type: SOT23-8 Plastic Package Note 1 PIN 1 E E1 b FUSED LEAD Note 2 A c e DESIGNATION A A1 b c D e E E1 L Theta A1 DESCRIPTION OVERALL HEIGHT STANDOFF LEAD WIDTH LEAD THICKNESS PACKAGE LENGTH LEAD PITCH LEAD TIP SPAN PACKAGE WIDTH FOOT LENGTH FOOT ANGLE DIE L METRIC 1.20 +/-.25 mm .100 +/-.05 mm .365 mm TYP .127 mm TYP 2.90 +/-.10 mm .65 mm TYP 2.80 +/-.20 mm 1.60 +/-.10 mm .45 +/-.10 mm 1.5 +/-1.5 DEG θ ENGLISH 0.05 +/-.250 in .004 +/-.002 in .014 in .005 in .114 +/-.004 in .026 in .110 +/-.008 in .063 +/-.004 in .018 +/-.004 in 1.5 +/-1.5 DEG NOTE 3 3 3 3 1,3 3 3 2,3 3 Notes 1. The package length dimension includes allowance for mold mismatch and flashing. 2. The package width dimension includes allowance for mold mismatch and flashing. 3. Primary dimensions are in metric millimeters. The English equivalents are calculated and subject to rounding error. For additional information and latest specifications, see our website: www.triquint.com 13 TQ5631 Data Sheet 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 Fax: (503) 615-8900 For technical questions and additional information on specific applications: 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 © 1998 TriQuint Semiconductor, Inc. All rights reserved. Revision A, March, 2000 14 For additional information and latest specifications, see our website: www.triquint.com