RF/IF Down-Converter + PLL Frequency Synthesizer ICs for GPS Receivers

Transcription

1 Application Note RF/IF Down-Converter + PLL Frequency Synthesizer ICs for GPS Receivers Usage and Applications of µpb1005k Document No. P14827EJ1V0AN00 (1st edition) Date Published September 2000 N CP(K) 2000 Printed in Japan

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3 NESAT (NEC Silicon Advanced Technology) is a trademark of NEC Corporation. The information in this document may be revised without notice. This document introduces general applications of the products in this series. The application circuits and circuit constants in this document are not intended for use in actual mass production design. In addition, please take note that restrictions of the application circuit or standardization of the application circuit characteristics are not intended. Especially, characteristics of high-frequency ICs change depending on the external components and mounting pattern. Therefore the external circuit constants should be determined based on the required characteristics on your planned system referring to this document and characteristics should be checked before using these ICs. The information in this document is current as of September, The information is subject to change without notice. For actual design-in, refer to the latest publications of NEC's data sheets or data books, etc., for the most up-to-date specifications of NEC semiconductor products. Not all products and/or types are available in every country. Please check with an NEC sales representative for availability and additional information. No part of this document may be copied or reproduced in any form or by any means without prior written consent of NEC. NEC assumes no responsibility for any errors that may appear in this document. NEC does not assume any liability for infringement of patents, copyrights or other intellectual property rights of third parties by or arising from the use of NEC semiconductor products listed in this document or any other liability arising from the use of such products. No license, express, implied or otherwise, is granted under any patents, copyrights or other intellectual property rights of NEC or others. Descriptions of circuits, software and other related information in this document are provided for illustrative purposes in semiconductor product operation and application examples. The incorporation of these circuits, software and information in the design of customer's equipment shall be done under the full responsibility of customer. NEC assumes no responsibility for any losses incurred by customers or third parties arising from the use of these circuits, software and information. While NEC endeavours to enhance the quality, reliability and safety of NEC semiconductor products, customers agree and acknowledge that the possibility of defects thereof cannot be eliminated entirely. To minimize risks of damage to property or injury (including death) to persons arising from defects in NEC semiconductor products, customers must incorporate sufficient safety measures in their design, such as redundancy, fire-containment, and anti-failure features. NEC semiconductor products are classified into the following three quality grades: "Standard", "Special" and "Specific". The "Specific" quality grade applies only to semiconductor products developed based on a customer-designated "quality assurance program" for a specific application. The recommended applications of a semiconductor product depend on its quality grade, as indicated below. Customers must check the quality grade of each semiconductor product before using it in a particular application. "Standard": Computers, office equipment, communications equipment, test and measurement equipment, audio and visual equipment, home electronic appliances, machine tools, personal electronic equipment and industrial robots "Special": Transportation equipment (automobiles, trains, ships, etc.), traffic control systems, anti-disaster systems, anti-crime systems, safety equipment and medical equipment (not specifically designed for life support) "Specific": Aircraft, aerospace equipment, submersible repeaters, nuclear reactor control systems, life support systems and medical equipment for life support, etc. The quality grade of NEC semiconductor products is "Standard" unless otherwise expressly specified in NEC's data sheets or data books, etc. If customers wish to use NEC semiconductor products in applications not intended by NEC, they must contact an NEC sales representative in advance to determine NEC's willingness to support a given application. (Note) (1) "NEC" as used in this statement means NEC Corporation and also includes its majority-owned subsidiaries. (2) "NEC semiconductor products" means any semiconductor product developed or manufactured by or for NEC (as defined above). M8E Application Note P14827EJ1V0AN00 3

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5 CONTENTS 1. INTRODUCTION PRODUCT CONCEPT PRODUCT FEATURES Main Features Package APPLICATION DESIGN EXAMPLES Application design examples External Component Examples RF Matching Circuit and RF Filter Characteristics VCO Design Temperature Dependence of VCO Characteristics Loop Filter Design PLL CHARACTERISTICS Standard Spectrum Waveform and C/N Characteristics Lockup Time Characteristics nd IF Output Spectrum Characteristics CONCLUSION APPENDIX (1) Smith charts for input/output ports (2) External filter example and characteristics (3) Related documents CAUTIONS (1) Observe precautions for handling because this device, which employs an ultra-fine process, is very sensitive to electrostatic discharges. (2) The bypass capacitor should be attached to the VCC pin. (3) Design the loop filter constant according to the VCO to be used. (4) Form the ground pattern as wide as possible. (5) Insert a DC cut capacitor for high-frequency signal I/O pins. (6) When soldering, leave the bias in the OFF status unless evaluating the VCO. Application Note P14827EJ1V0AN00 5

6 1. INTRODUCTION The Global Positioning System (GPS) was first developed in the United States and is now also widely used in civilian applications all over the world. GPS receivers are used as position information receivers such as those in car navigation systems, and the market for such receivers is rapidly expanding throughout the world, including Japan. This market expansion is resulting in lower prices for GPS modules, which has effectively broadened their application scope to include systems such as notebook computers and wristwatch-size miniature portable receivers. Rising market needs for portable systems that include GPS modules have boosted demand for GPS-related ICs that are lower priced, consume less power, and come in compact packages that enable high-density mounting. NEC already sells the µpc2756t/tb and the µpc2753gr frequency down-converters for GPS receivers. To meet the needs cited above, NEC has also been developing and commercializing new ICs that integrates a PLL frequency synthesizer and frequency down-converter on the same chip. 2. PRODUCT CONCEPT The µpb1005k is a high-frequency silicon monolithic IC developed for frequency converters used in GPS receivers. This IC integrates on a single chip a frequency converter (down-converter) with an operating frequency band corresponding to the civilian GPS frequency (L1 frequency = MHz) and a PLL synthesizer that stabilizes the receiving frequency. This IC uses NEC s own NESAT TM (NEC Silicon Advanced Technology) III ultrafine fabrication process for 0.6 µm emitter width. The fact that the only frequency for civilian GPS is L1 enables the use of a fixed-frequency division method that eliminates input of frequency data or switching of frequency division values, which are required in conventional PLL frequency synthesizers. The reference frequency of MHz is provided in accordance with the input frequency specification for demodulation ICs, which are currently the dominant type. This IC comes in a 36-pin plastic QFN package that enables high-density integration of chip sets. 6 Application Note P14827EJ1V0AN00

7 3. PRODUCT FEATURES 3.1 Main Features The main features of this new product are summarized below. (1) Double conversion method: Enables use of dielectric RF filter. (2) High integration of RF block: Single-chip integration of RF/IF down-converter and PLL frequency synthesizer (3) Enables high density and surface mounting: 36-pin plastic QFN package (4) Eliminates channel selection frequency data: Uses fixed frequency division with lockup activated at power-on. (5) Large phase comparison frequency: The reference spurious signal output does not appear in the vicinity of the VCO carrier, which facilitates loop filter design. (6) Enables effective use of external filter: Accepts a higher frequency for 1st IF, which makes it easier to reduce spurious emissions due to insertion of LC filters for the 1st and 2nd IF. (7) 2nd IF output by clipped wave: An on-chip differential 2nd IF amplifier provides a limiter effect. (8) Gain adjustment enabled in IF mixer: When necessary, an external control circuit can be connected to enable auto gain control. (9) Reference frequency: MHz (10) Power supply voltage VCC = 2.7 to 3.3 V: Applicable for portable GPS receivers. Table 3-1 provides a product overview, and Figure 3-1 show the product s pin configuration and internal block diagram. See the data sheet for the product specifications. Table 3-1. Product Overview Parameter Reference frequency 2nd IF frequency Receiving frequency Power supply voltage Power consumption Package µpb1005k MHz MHz MHz 2.7 to 3.3 V 45.0 ma 36-pin plastic QFN Application Note P14827EJ1V0AN00 7

8 Figure 3-1. µpb1005k Pin Configuration and Internal Block Diagram IF-MIXout N.C. VGC (IF-MIX) VCC (IF-MIX) N.C. IF-MIXin GND (IF-MIX) RF-MIXout VCC (RF-MIX) RF-MIXin GND (2ndIF-AMP) 27 2ndIFin1 2ndIFin2 2ndIFbypass VCC (2ndIF-AMP) ndIFout N.C. REFout N.C. VCC (Reference block) GND (RF-MIXin) VCC (1stLO-OSC) 1stLO-OSC1 25 1stLO-OSC2 GND (1stLO-OSC) 8 VCC (Phase detector) 2 PD PD-Vout N.C. REFin N.C. GND (Divider block) LOout VCC (Divider block) GND (Phase detector) PD-Vout1 PD-Vout2 8 Application Note P14827EJ1V0AN00

9 3.2 Package The µpb1005k uses a non-lead 36-pin QFP (QFN) package. The pins located at the four corners of the 36-pin QFN package (pins 9-10, pins 18-19, pins 27-28, and pins 36-1) are called island pins. They are provided to fix the lead frame and do not serve any other function, thus they do not get connected inside the chip. These island pins are thinner than the other function pins. They are not to be soldered, but in order to avoid contact between brace pins and other pins, trace a pattern and leave the brace pins unconnected. Figure Pin Plastic QFN (Unit: mm) 4 C ± ± ± ± ± ± 0.2 Pin 36 Pin ± ± ± ± MAX. 0.5 ± Back side of product Application Note P14827EJ1V0AN00 9

10 4. APPLICATION DESIGN EXAMPLES 4.1 Application design examples Figure 4-1 show a circuit example of a GPS frequency converter block that was designed using an application evaluation board for this IC. Figure 4-2 shows examples of implemented patterns. This application evaluation board is a PCB used to evaluate frequency converter blocks for GPS receivers that include the µpb1005k, and the board has printed patterns that enable mounting of external ICs, filters, to TCXO. Figure 4-1. Application Circuit Example VCC (3 V) pf 0.1 µ F 1.95 kω 2nd IFout 0.1 µ F pf pf pf REFout VGC 1st LO monitor RFin 2nd IF filter 0.01 µ F pf µ F pf st IF filter pf pf pf 6.8 RF amplifer RF filter nh pf pf 1 pf PD pf 24 pf 6.2 kω pf pf nf pf 1.2 kω pf TCXO pf LOout pf 4.7 kω 4.7 kω 3.9 nh pf pf The application evaluation board shown in Figure 4-2 has printed patterns for monitoring the following items, in addition to the application s input/output operations. <1> 1st LO monitor: Monitoring is enabled by coupling a capacitor to pin 35 (1st IF output pin of RF mixer). This can be used to monitor the oscillation frequency when adjusting the external circuit constant of the 1st LO. It can also be used to monitor image leakage, the 1st IF frequency, as well as 2nd LO leakage to the 1st IF. <2> Loout: This enables monitoring of the phase comparison frequency. <3> 1st LO ex-in: This can be used when evaluating external input from a signal generator without configuring a VCO using a PLL. 10 Application Note P14827EJ1V0AN00

11 Figure 4-2. Application Evaluation Board Implementation Example (a) Top view 70 mm NEC 1st LO monitor C10 2nd IF filter C9 C8 C7 2nd IF out C11 50 mm RF in C13 C12 µ PB1005K R3 R1 R4 C4 C5 TCXO out C6 C1 L1 C2 R2 C3 1st LO ex-in µ PB1005K LO out 3 mm 20 mm Application Note P14827EJ1V0AN00 11

12 (b) Bottom view C 18 C 19 C 20 C17 1st IF filter C21 C 22 µ PC 2749 C24 C25 C 16 C 15 C 14 V-D R5 L2 RF filter C23 TCXO 12 Application Note P14827EJ1V0AN00

13 Table 4-1. Ratings for External Capacitors and Resistors Component Type Symbol Rating Chip capacitor C1 1 pf C2, C5, C6, C10, C12, C13, C16 to C19, C21 to C pf C3 C pf 33 nf C7, C8 0.1 µf C µf C11 1 µf C14, C15 24 pf (UJ) C pf Chip inductor L1 6.8 nh L2 3.9 nh Chip resistor R1 6.2 kω R2, R5 4.7 kω R3 R4 1.2 kω 0 Ω The chip capacitor and chip resistor manufactured by Murata Manufacturing Co., Ltd. are used. 4.2 External Component Examples Table 4-2 lists external components other than capacitors, inductors, and resistors. These types of commercial components can be used. The following components and manufacturers are listed only as examples, so any components whose characteristics are similar to the listed components can be used. Table 4-2. External Component Examples Component Type Part number Manufacturer RF amplifier SiMMIC µpc2749tb NEC RF filter Dielectric BPF Type TDF, TDF3A-1575B-10 Toko 1st IF filter BPF for LC Type 5CCEW, 662BBX-037 Toko 2nd IF filter LPF for LC Type FST, 630LKN-1006 Toko Inductor for VCO Layer-built chip L LL1608-F3N9S (3.9 nh) Toko V-Di Varactor diode 1SV285 Toshiba Output buffer TC7S04F, etc. Toshiba Reference signal oscillator TCXO TCXO-201C1 ( MHz) Kinseki Caution The external components and their characteristics are presented in summary form. For details concerning these external components, including these filters, contact the respective manufacturers. Application Note P14827EJ1V0AN00 13

14 4.3 RF Matching Circuit and RF Filter Characteristics In dielectric RF filters and other filters, 50 Ω impedance is connected to inputs and outputs to regulate insertion loss and attenuation characteristics. Figure 4-3 illustrates an RF filter s S11 characteristics when ZL = 50 Ω and when ZL 50 Ω. As shown in the figure, this RF filter is best suited for applications in which ZS = ZL = 50 Ω. Figure 4-3. S11 of RF Filter (a) When ZL = 50 Ω S11 REF Units m Units/ Ω Ω log MAG. S11 REF 0.0 db db/ db MARKER GHz 1 CENTER GHz START STOP GHz GHz START STOP GHz GHz (b) When ZL = 100 Ω S11 REF Units m Units/ Ω Ω log MAG. S11 REF 0.0 db db/ db MARKER GHz CENTER GHz 1 START GHz STOP GHz START GHz STOP GHz 14 Application Note P14827EJ1V0AN00

15 The µpc2749tb can be used at the front stage of the RF filter as an internal 50 Ω matching RF amplifier, and the RF input pin that becomes the RF filter load should be configured with a matching circuit that includes a DC cut capacitor, an external series inductor, and an external parallel capacitor. Figure 4-4 illustrates the S11 characteristics of the RF input pin. As shown in this figure, this makes matching relatively simple. Since the RF filter is inserted between the RF mixer input pin and the front-stage RF amplifier, it is useful for image level suppression. Figure 4-4. S11 Characteristics for 50 Ω Impedance Matching at RF Input Pin Monitor (RF filter output mount section) <1> 6.8 nh 1 pf Connector S11 REF 1.0 Units munits/ Ω Ω S11 log MAG. REF 0.0 db db/ db MARKER GHz MARKER GHz 1 1 START GHz STOP GHz START GHz STOP GHz Application Note P14827EJ1V0AN00 15

16 4.4 VCO Design Basic design Since the base pins of the differential amplifier type oscillator protrude, obtain the oscillation by cutting off the DC flow and allowing positive feedback through the varactor diode and the inductor. Use a varactor diode that has a small minimum capacitance, such as Toshiba s 1SV285. The VCO control voltage should be applied via a resistor with a resistance of 4.7 kω, for example. Determine the relation between the VCO control voltage and the oscillation frequency based on the varactor diode s variable capacitance value and the inductor s value. In NEC s application evaluation, L = 3.9 nh because the VCO oscillation frequency is MHz. Verification after mounting on PCB When it is not possible to verify the parasitic parameter effect of the PCB only by theoretical VCO design, we suggest comparing theoretical design with PCB evaluation results in the manner described below. While monitoring local leakage via a spectrum analyzer that has been connected to the 1st LO monitor, apply a 1.5 V control voltage to VCO. Next, adjust the inductor s value or the mounting position. Lockup is enabled when the inductor s value comes to match the 1st LO frequency s TYP value. Figure 4-5 illustrates the VCO sensitivity characteristics and shows a circuit diagram. Figure 4-5. VCO Sensitivity Characteristics Example and Circuit Diagram Control voltage VCONT (V) VCO oscillation frequency for 1st LO fvco (GHz) VCC Internal (to IC) External DC cut 3 4 VCC To RF-MIX or prescaler input amplifier Control voltage (from PLL loop filter) L DC cut Application Note P14827EJ1V0AN00

17 4.5 Temperature Dependence of VCO Characteristics Configure the VCO so as to minimize frequency fluctuations caused by the ambient temperature. If the VCO frequency reaches a range that disables PLL operations of this IC due to the ambient temperature fluctuation by the external components temperature coefficient, lockup operation becomes impossible. Figures 4-6 and 4-7 show the dependence on ambient temperature of VCO sensitivity characteristics when using the CH standard, which uses a small rate of change in temperature compensation, and UJ standard, which uses a large rate of change in temperature compensation, for the DC cut capacitor of the base pin of the differential amplifier type oscillator, respectively. Using a UJ standard capacitor is particularly effective for suppressing frequency fluctuations at low temperatures. Also, since the slope of the VCO sensitivity curve is determined by the varactor diode, use a varactor diode with small frequency fluctuation characteristics within the VCO control voltage range (0 to 3.0 V). Figure 4-6. VCO Sensitivity Characteristics when Using CH Standard for DC Cut Capacitor Figure 4-7. VCO Sensitivity Characteristics when Using UJ Standard for DC Cut Capacitor Control voltage VCONT (V) TA = +85 C TA = +25 C Control voltage VCONT (V) TA = +85 C TA = +25 C 0.5 TA = 40 C 0.5 TA = 40 C VCO oscillation frequency for 1st LO fvco (GHz) VCO oscillation frequency for 1st LO fvco (GHz) Application Note P14827EJ1V0AN00 17

18 4.6 Loop Filter Design Adjust the loop filter constant until the carrier s C/N drops below 40 dbc at 12.5 khz detuning. Note that there is a relation between the loop filter constant and the VCO sensitivity characteristics. The parameters and corresponding relational expressions required for designing the loop filter are shown below (persons wishing to study these parameters and relevant logic should see the existing PLL documentation.) Parameters required for design of loop filter PLL block parameters: Phase comparator gain Kφ, VCO gain KV, dividing ratio N PLL loop parameters: Damping filter ζ, natural angular frequency ωn Relational expressions for active lag-lead filter CC R1 = Kφ KV N ω 2 n C (Ω) R2 C R2 = 2 ζ ω n C (Ω) Phase/frequency comparator output R1 Loop amplifier To VCO CC = 1 R2 (5 to 10) ω n (F) Conversion gain of phase comparator Kφ = VOH VOL 2 1 2π (V/rad) Kφ = VCC GND 2 1 2π (V/rad)...* * Approximate expression VCO sensitivity KV = f V 2π (rad/v sec) N count (dividing ratio for VCO input signal) N = Application Note P14827EJ1V0AN00

19 The following external constant values were obtained by tests using the design shown in the application circuit example illustrated in Figure 4-1. Loop filter circuit constants C = 33 nf R2 = 1.2 kω Cad was added for suppression of spurious signal output. Cad = 1800 pf From phase/frequency comparator R kω on chip RL To power supply To VCO C R2 Cad Internal (to IC) External Since the VCO oscillation frequency and the R1 and N values are all fixed in this IC, the relations between loop filter circuit constants that optimized characteristics through experiments were obtained, and a method for easily obtaining C and R2 from these interrelationships was evolved. Since this IC is an active-filter type, the following circuit constant expressions for active filters are used. Kφ KV R1 = N ω n 2 C 2 ζ ωn = R2 C From these two expressions, it follows that: R1 = Kφ KV R22 C N 4 ζ 2 KV R2 2 C = R1 4 ζ 2 N Kφ After testing the µpb1005k to obtain optimum characteristics, the external circuit constants for the loop filter were found to be C = 33 nf, R2 = 1.2 kω (R1 is on chip). The gain of the configured VCO is: KV = ( ) MHz 2 π / 3.0 V = (rad/v sec) Furthermore, the following empirical value is obtained based on the values for C and R2. KV R2 2 C = = N 200 Thus the following expression is obtained. Empirical value µpb1005k loop filter empirical expression R2 = N KV C Where N = 200. The KV value may vary depending on the components that are used, so the C and R2 values obtained via the above relational expressions should be considered as a guide for obtaining optimized values via testing on your circuit board. Application Note P14827EJ1V0AN00 19

20 5. PLL CHARACTERISTICS 5.1 Standard Spectrum Waveform and C/N Characteristics The 1st LO monitor was used to measure the VCO s carrier spectrum. Figure 5-1 shows the VCO carrier spectrum. Main results When VCONT voltage (1.5 V) was externally applied, the oscillation frequency became MHz and the VCO sensitivity characteristics were obtained by adjusting the inductor s mounting position. (See Figure 4-5.) When the C/N value exceeds 78 dbc/hz based on 1 khz detuning, the characteristic of a noise level of 65 dbc/hz generally set by GPS manufacturers is met (according to NEC s marketing research). Figure 5-1. VCO Carrier Spectrums (Monitored via 1st LO Monitor) REF 10.0 dbm ATTEN 10 db MKR GHz dbm REF 10.0 dbm ATTEN 10 db MKR khz db 10 db/ 10 db/ MARKER GHz dbm MARKER khz db CENTER GHz RES BW 1 00 khz VBW 1 khz SPAN 5.00 MHz SWP 10.0 sec CENTER GHz RES BW 1 khz VBW 10 Hz SPAN 5.00 khz SWP 10.0 sec REF 10 db/ 10.0 dbm ATTEN 10 db MKR khz db VAVG 8 MKR db/hz REF 20.0 dbm ATTEN 10 db 1.00 khz 10 db/ MARKER khz db MARKER 1.00 khz db/hz CENTER GHz RES BW 3 khz VBW 30 Hz SPAN 201 khz SWP 10.0 sec CENTER GHz RES BW 100 Hz VBW 30 Hz SPAN khz SWP 4.6 sec 20 Application Note P14827EJ1V0AN00

21 5.2 Lockup Time Characteristics The lockup time was checked using a board assembled from the application circuit example. The lockup time of the PLL synthesizer at power-on was measured for the reference characteristics of the application circuit example. The power supply equipment for the circuit s power supply pin was replaced with a pulse generator and the supply voltage (3 V) was turned ON and OFF repeatedly, after which the zero-span mode of the spectrum analyzer was used to analyze the VCO carrier leak signal at the 1st LO monitor pin, and the length of time until the GHz oscillation power comes within ±1 db and reaches lockup was measured. Figure 5-2 shows the trace plot data for the rising edge of the carrier in the zero-span mode. The lockup time from power-on to normal operation was approximately 90 µs. Figure 5-2. Measurement of Lockup Time (via Spectrum Analyzer in Zero-Span Mode) ATTEN 10 db RL 0 dbm 10 db/ 90 µ s 3 V 0 V CENTER GHz RBW 1.0 MHz VBW 3.0 MHz SPAN 0 Hz SWP 500 µ s 5.3 2nd IF Output Spectrum Characteristics Figure 5-3 shows the 2nd IF output spectrum characteristics. This spectrum was measured using a spectrum analyzer to monitor the 2nd IF output frequency based on a 100 dbm input level to the first RF amplifier (µpc2749tb) in the application circuit example. Application Note P14827EJ1V0AN00 21

22 Figure nd IF Output Spectrum Characteristics Figure 5-4. Measurement Circuit REF 10.0 dbm ATTEN 20 db MKR GHz dbm 10 db/ MARKER MHz dbm 2nd IF OUT <22> 1.95 kω 50 Ω SA START 100 khz RES BW 30 khz VBW 1 khz STOP 8.00 MHz SWP 290 msec Figure 5-3 shows the 2nd IF output spectrum characteristics, and Figure 5-4 shows the measurement circuit that was used. The 2nd IF output power specification for this IC is 14.5 dbm (MIN.), but a value of 30.0 dbm was detected in the measurement data in Figure 5-3. The specification is the value from the voltage gain, whereas the measurement value of the spectrum analyzer in Figure 5-3 is due to the power gain. Since this data is obtained via the measurement circuit shown in Figure 5-4, which includes a 1.95 kω load and an instrument impedance of 50 Ω, the actual value must be converted as follows. Output power = (read value of spectrum analyzer) + 10 log (2000/50) = (read value of spectrum analyzer) + 16 dbm. Thus, calculation of the measurement data in Figure 5-3 yields the following: 2nd IF output power = 30 dbm + 16 dbm = 14 dbm Figure 5-5 shows the 2nd IF output amplitude measured with an oscilloscope. An output amplitude value exceeding 600 mvp-p was detected for a 100 dbm input level to the application circuit s first RF amplifier (µpc2749tb). This data indicates a square wave of approximately 800 mvp-p. 22 Application Note P14827EJ1V0AN00

23 Figure nd IF Output Amplitude 200 m n V 0.00s 50 s / Freq (1) = MHz VP-P (1) = mv 6. CONCLUSION The above has described the usage and applications of the µpb1005k RF/IF down-converter + PLL frequency synthesizer ICs for GPS receivers. Refer to the appendix for characteristics concerning examples of commercially available components used as external components for this IC. Application Note P14827EJ1V0AN00 23

24 APPENDIX (1) Smith charts for input/output ports (VCC = 3.0 V) S11 1: Ω Ω pf MHz RF-MIXin S11 1: Ω Ω pf MHz RF-MIXin MARKER GHz MARKER MHz 1 1 START MHz STOP MHz START MHz STOP MHz S22 1: Ω Ω nh MHz RF-MIXout S11 1: kω kω pf MHz 2nd IFin1 MARKER MHz MARKER MHz 1 1 START MHz STOP MHz START MHz STOP MHz 24 Application Note P14827EJ1V0AN00

25 (2) External filter example and characteristics (For corresponding components, refer to Table 4-1 Ratings for External Capacitors and Resistors.) Source: Toko, Inc. Attenuation (db) TDF3A-1575B-10 Sample No. : Center Frequency : 1575 MHz Passband Insertion Loss Passband Ripple Passband V.S.W.R. Attenuation Span: 500 MHz 1.97 db max db 1.27 max Return Loss (db) DIELECTRIC BANDPSS FILTER TDF Series Toko No. : TDF3A-1575B-10 Dimensions GND Marking. 5.7 A ± 0.5. max. T A = 5.6 B = 2.5 C = 3.0 Specifications Center Frequency (Fo) Passband Width Input Output Impedance Insertion Loss in Passband Ripple in Passband V.S.W.R. in Passband Attenuation OUT 4.7 B IN GND Tolerance : ±0.3 Unit : mm : MHz : Fo ± 5.0 MHz : 50 Ω : 2.7 db max. : 1.0 db max. : 2.0 max. : 7.0 db min. at Fo ± 35 MHz : 30 db min. at Fo ± 140 MHz : 28 db min. at Fo ± 140 MHz at 1, MHz db at 1, MHz db at 1, MHz 9.00 db at 1, MHz db Date: Instrument : WILTRON 37269A 5CCEW 662BBX-037 MKR[ 250]:61.38 MHz A[*]:MAGTD 3.45 db B[*]:B 3.32 db : :16 MO 10 db db 1 db/ 4.65 db 10 db /div. 10 MHz /div. 1 kω <6> <4> <1><2><3> 1 kω INSTRUMENTS 3577A (hp) Use pins 4 and 6 in a floating state db /div. 5 MHz /div CF:61.38 MHz OUT[B]:0.00 dbm ST:4.20 sec IRG[R]:0 dbm IRG[T]:0 dbm MAGTD SPAN :100 MHz EL:0.00 cm RBM:10 khz VBW:10 khz 50 Ω OFFSET CTR ATTENUAION [db] GROUP DELAY [ sec] µ Measurement circuit (Bottom view) Key Rin <1><2><3> <4><5><6> Rout Rin = 50 Ω Rout = 50 Ω FREQUENCY [MHz] 0 <12><11><10> <9><8><7> Caution For details concerning the characteristics of external components, contact the respective manufacturers. Application Note P14827EJ1V0AN00 25

26 Reference oscillator (TCXO) Source: Kinseki (VC-) TCXO-201C1 Temperature compensation crystal oscillator/tcxo, VC-TCXO Features For cellular phone (VC-) TCXO Surface-mounting (ceramic base) type enabling automatic mounting Low profile, 2.4 mm high Reflow soldering can be used. Package Dimensions (VC-) TCXO-201C ± ± ± R ± ± 0.1 CONNECTION 1 : NC 4 : GND 5 : OUTPUT 6 : GND 7 : VC VC-TCXO NC TCXO 8 : +DC Specifications Part No. Reference frequency Parameter Dimensions (mm) TCXO-201C1 VC-TCXO-201C1 Note , 13.0, 14.4, 14.85, 15.36, 19.2, MHz Frequency stability ± / 30 to +75 C Note 2 Secular change ± MAX./year Supply voltage +5 V ± 5% Note 3 Consumption current 2.0 ma MAX. Output Output load 10 kω /10 pf Output level 1VP-P MIN. (DC cut) Frequency variable range Control voltage frequency characteristic Volume ± MIN. ± MIN./+2.5 ± 2V (normal direction) 0.27 cc Notes 1. For the reflow conditions, contact an NEC sales representative. 2. Product with frequency stability of ± / 20 to +75 C can also be manufactured. 3. Products with as supply voltage of 3.0 V can also be manufactured. Caution For the detailed characteristics of the external component examples, contact an NEC sales representative. 26 Application Note P14827EJ1V0AN00

27 (3) Related documents Application Note Fundamentals of Frequency Synthesizer Circuits Employing Phase-Locked Loop Document No.: P12196E (Old Document No.: IEB-1003) Data Sheet µpb1005k Document No.: P14016E Data Sheet µpc2749tb Document No.: P13489E Application Note Use and Application of Silicon High-Frequency Wideband Amplifier MMIC (µpc2749tb, etc.) Document No.: P11976E Application Note P14827EJ1V0AN00 27

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