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NATIONAL SEMICONDUCTOR LMV225/LMV226/LMV228 Manual

1. ERROR dB 1 5 60 40 30 20 RF INPUT POWER dBm 20076044 Output Variation vs RF Input Power Normalized to 25 C 2000 MHz LMV226 85 C Al SIMA ERROR dB LL Leu 5 10 0 10 RF INPUT POWER dBm 20076062 Output Variation vs RF Input Power Normalized to 25 C 1900 MHz LMV226 ERROR dB 40 30 RF INPUT POWER dBm 20 20076061 Output Variation vs RF Input Power Normalized to 25 C 2000 MHz LMV225 ERROR dB 50 40 30 20 10 RF INPUT POWER dBm 20076015 Output Variation vs RF Input Power Normalized to 25 C 2000 MHz LMV228 1 5 1 0 0 5 ERROR dB 1 5 50 40 30 RF INPUT POWER dBm 20 20076045 www national com Typical Performance Characteristics unless otherwise specified 2 7V 25 C Continued PSRR vs Frequency LMV225 LMV226 and LMV228 PSRR dB 70 60 50 40 30 20 10 1k 10k 100k FREQUENCY Hz 20076023 RF Input Impedance vs Frequency Resistance and Reactance LMV225 LMV226 and LMV228 IMPEDANCE 150 100 04 06 08 10 12 14 16 1 8 2 0 FREQUENCY GHz 20076024 15 www national com 86CcAW 1 92 CAW T1 SCCAW T LMV225 LMV226 LMV228 Application Notes CONFIGURING A TYPICAL APPLICATION The LMV225 LMV226 LMV228 are power dete
2. Vour V Vour V V Output Voltage and Log Conformance vs RF Input Power 900 MHz LMV226 aL LT TTT TT d Es IN RF INPUT POWER dBm 20076053 Output Voltage and Log Conformance vs RF Input Power 1800 MHz LMV225 T 5 x ha fd 50 40 30 20 10 0 10 20 RF INPUT POWER dBm 20076007 Output Voltage and Log Conformance vs RF Input Power 1800 MHz LMV228 5 4 3 2 18 te 1 5 2 3 4 5 0 00 50 40 30 20 10 0 10 20 RF INPUT POWER dBm 20076037 www national com Typical Performance Characteristics uniess otherwise specified Voo 2 7V 25 C Continued Output Voltage and Log Conformance vs RF Input Power 1900 MHz LMV225 Vout V RF INPUT POWER dBm 20076008 Output Voltage and Log Conformance vs RF Input Power 1900 MHz LMV228 5 5 4 3 aan 5 ZZ 1 8 3 Wo S gt 16 2 3 4 5 0 00 50 40 30 20 10 0 10 20 RF INPUT POWER dBm 20076038 Output Voltage and Log Conformance vs RF Input Power 2000 MHz LMV226 Y Vout V S ERROR dB RF INPUT POWER dBm 20076056 V Vout V Output Voltage and Log Conformance vs RF Input Power 1900 MHz LMV226 RF INPUT POWER dBm 20076055 Output Voltage and Log Conformance vs RF Input Power 2000 MH
3. National Semiconductor LMV225 LMV226 LMV228 RF Power Detector for CDMA and WCDMA in micro SMD General Description The LMV225 LMV226 LMV228 are 30dB RF power detec tors intended for use in CDMA and WCDMA applications The device has an RF frequency range from 450 MHz to 2 GHz It provides an accurate temperature and supply com pensated output voltage that relates linearly to the RF input power in dBm The circuit operates with a single supply from 2 7V to 5 5V The LMV225 LMV226 LMV228 have an inte grated filter for low ripple average power detection of CDMA signals with 30 dB dynamic range Additional filtering can be applied using a single external capacitor The LMV225 has an RF power detection range from 30 dBm to 0 dBm and is ideally suited for direct use in combi nation with resistive taps The LMV226 LMV228 have a de tection range from 15 dBm to 15 dBm and are intended for use in combination with a directional coupler The LMV226 is equipped with a buffered output which makes it suitable for GSM EDGE GPRS and TDMA applications The device is active for Enable HI otherwise it is in a low power consumption shutdown mode During shutdown the output will be LOW The output voltage ranges from 0 2V to 2V and can be scaled down to meet ADC input range re quirements The LMV225 LMV226 LMV228 power detectors are offered in the small 1 0 mm x 1 0 mm X 0 6 mm micro SMD pack age August 2004 Features 30 dB linea
4. 1 0mm BUMP PITCH 500um BUMP DIAMETER 300um SOLDER DOT DIAMETER 125um PASSIVATION OPENING 20076002 Top View Pin Description Pin Name Description Positive Supply Voltage Power Ground Power Supply terminated with 50Q in series with 45 pF DC voltage determines enable state of the device HIGH device active AC voltage is the RF input signal to the detector beyond 450 MHz The RF E pin is internally Output Ground referenced detector output voltage linear in dBm Ordering Information Package Part Number Package Marking Transport Media NSC Drawing LMV225TL 250 Units Tape and Reel LMV225TLX 3k Units Tape and Reel i LMV226TL 250 Units Tape and Reel 4 Bump micro SMD 4 A _ TLAO4AAA LMV226TLX 3k Units Tape and Reel LMV228TL 250 Units Tape and Reel LMV228TLX 3k Units Tape and Reel Note This product is only offered with lead free bumps www national com BCCAINT 9CCAIN V SCCAWT LMV225 LMV226 LMV228 Block Diagrams DD A2 ENABLE LMV225 GND 20076003 LMV225 OUT LMV226 GND 20076049 LMV226 LMV228 GND 20076047 LMV228 www national com Typical Performance Characteristics Unless otherwise specified Vpp 2 7V Ty 25 C Supply Current vs Supply Voltage LMV225 SUPPLY CURRENT mA SUPPLY VOLTAGE V 20076004 Supply Curre
5. For guaranteed specifications and the test conditions see the Electrical Characteristics Note 2 Human body model 1 5 in series with 100 pF Machine model OQ in series with 100 pF Note 3 The maximum power dissipation is a function of Tj max and Ta The maximum allowable power dissipation at any ambient temperature is Tu MAx All numbers apply for packages soldered directly into a PC board Note 4 Electrical Table values apply only for factory testing conditions at the temperature indicated Factory testing conditions result in very limited self heating of the device such that Tj TA No guarantee of parametric performance is indicated in the electrical tables under conditions of internal self heating where Ty gt T4 Note 5 Power in dBV dBm 13 when the impedance is 500 Note 6 All limits are guaranteed by design or statistical analysis Note 7 Typical values represent the most likely parametric norm Note 8 Device is set in active mode with a 10 resistor from Vpp to RFij En RF signal is applied using a 500 RF signal generator AC coupled to the RFjy Ey pin using a 100 pF coupling capacitor Note 9 Turn on time is measured by connecting a 10 resistor to the RFjy Ew pin Be aware that in the actual application on the front page the RC time constant of resistor Ro and capacitor C adds an additional delay www national com 6 Connection Diagram 4 Bump micro SMD 1 0mm
6. 2000 MHz LMV225 48 9 LMV226 25 5 LMV228 28 7 Vout Output Voltage No RF Input Power LMV225 222 400 Present LMV226 231 400 mV LMV228 244 400 lout Output Current LMV226 Only 4 5 5 3 mA Sourcing Sinking Rout Output Impedance No RF Input Power Present 23 7 29 en Output Referred Noise RF Input 1800 MHz 10 dBm for 700 nv JHz LMV225 and 5 dBm for LMV226 LMV228 Measured at 10 kHz www national com BCCAIN 1 92 CAW T SCCAWT LMV225 LMV226 LMV228 5 0 DC and AC Electrical Characteristics Continued Unless otherwise specified all limits are guaranteed to Vpp 5 0V T 25 C Boldface limits apply at temperature extremes Note 4 Symbol Parameter Condition Min Variation Due to Temperature 900 MHz RF n 0 dBm LMV225 Referred to 25 C 900 MHz RF y 15 dBm LMV226 Referred to 25 C LMV228 1800 MHz 0 dBm LMV225 Referred to 25 C 1800 MHz RF n 15 dBm LMV226 Referred to 25 C LMV228 1900 MHz 0 dBm LMV225 Referred to 25 C 1900 MHz RF 15 dBm LMV226 Referred to 25 C LMV228 2000 MHz RF 0 dBm LMV225 Referred to 25 C 2000 MHz RF 15 dBm LMV226 0 25 Referred to 25 C 0 34 LMV228 0 61 0 91 Note 1 Absolute Maximum Ratings indicate limits beyond which damage to the device may occur Operating Ratings indicate conditions for which the device is intended to be functional but specific performance is not guaranteed
7. a linear scale and the piecewise approximation of the logarithmic function Y LOG X EIA E A PX uN Fk WA EKA 20076021 FIGURE 9 Log Function on Lin Scale Figure 10 shows a logarithmic function on a logarithmic scale and the piecewise approximation of the logarithmic function E A K E A gt X Log 20076022 FIGURE 10 Log Function on Log Scale The maximum error for this approximation occurs at the geometric mean of a gain section which is e g for the third segment 2 al AVA 9 The size of the error increases with distance between the thresholds LAYOUT CONSIDERATIONS For a proper functioning part a good board layout is neces sary Special care should be taken for the series resistance R Figure 1 that determines the attenuation For high re sistor values the parasitic capacitance of the resistor may significantly impact the realized attenuation The effective attenuation will be lower than intended To reduce the para sitic capacitance across resistor R4 this resistor can be composed of several components in series instead of using a single component 19 www national com BCCAIN 1 92 CAW V SCCAWT LMV225 LMV226 LMV228 RF Power Detector for CDMA and WCDMA in micro SMD Physical Dimensions inches millimeters unless otherwise noted PKG SYMM 0 275 4X D550 PKG SYMM 0 5 1 i ipu z DIMENSION
8. depicted in Figure 1 2 25 2 00 1 75 1 50 1 25 1 00 0 75 0 50 LMV225 OUTPUT VOLTAGE V 0 25 0 00 50 40 30 20 10 0 10 20 30 40 POWER dBm 20076016 FIGURE 3 Typical power detector response Voy vs PA output Power OUTPUT RIPPLE DUE TO AM MODULATION A CDMA modulated carrier wave generally contains some amplitude modulation that might disturb the RF power mea surement used for controlling the PA This section explains the relation between amplitude modulation in the RF signal and the ripple on the output of the LMV225 LMV228 Expres sions are provided to estimate this ripple on the output The ripple can be further reduced by lowpass filtering at the output This is realized by connecting an capacitor from the output of the LMV225 LMV228 to ground Estimating Output Ripple The CDMA modulated RF input signal of Figure 3 can be described as Vin t Vin 1 cos 2 n f t 4 In which Vi is the amplitude of the carrier frequency and the amplitude modulation p t can be between 1 and 1 20076017 FIGURE 4 AM Modulated RF Signal The ripple observed at the output of the detector equals the detectors response to the power variation at the input due to AM modulation Figure 4 This signal has a maximum am plitude Vin 19 and a minimum amplitude Viy 1 1 where 1 can be maximum 2 and 1 be minimum 0 The amplitude of the ripple can be described with t
9. 0 mVpp Connecting a capacitor of 1 5 nF at the output to ground results a ripple of 12 MVpp The attenuation with 1 5 nF capacitor is then 20 log 200 12 24 4 dB This is very close to the calculated number of the previous para graph 1000 SS SSS SSS lt lt NO ADDITIONAL CAPACITOR 1 100 10 OUTPUT RIPPLE RF INPUT POWER dBm 20076025 FIGURE 6 Output Ripple vs RF Input Power PRINCIPLE OF OPERATION The logarithmic response of the LMV225 LMV226 LMV228 is implemented by a logarithmic amplifier as shown in Figure 7 The logarithmic amplifier consists of a number of cas caded linear gain cells With these gain cells a piecewise approximation of the logarithmic function is constructed 20076019 FIGURE 7 Logarithmic Amplifier Every gain cell has a response according to Figure 8 Ata certain threshold E the gain cell starts to saturate which means that the gain drops to zero The output of gain cell 1 is connected to the input of gain cell 2 and so on www national com Application Notes continued E FIGURE 8 Gain Cell X 20076020 All gain cell outputs are AM demodulated with a peak detec tor and summed together This results in a logarithmic func tion The logarithmic range is about 20 n log A where n number of gain cells A gain per gaincell Figure 9 shows a logarithmic function on
10. Note 4 Symbol Parameter Condition Units Ipp Supply Current Active Mode RFij Ey Vpp DC No RF Input Power Present mA Shutdown RF Ey GND DC No yA RF Input Power Present Logic Low Input Level V Note 6 VuicH Ey Logic High Input Level V Note 6 5 Turn on Time Note 9 No RF Input Power LMV225 Present Output Loaded LMV226 us with 10pF LMV228 t Rise Time Note 7 Step from no Power to 0 LMV225 dBm Applied Output Loaded with 10pF s Step from no Power to 15 LMV226 2 Loaded with 10pF 228 len Current into RF n En Pin pA Pin Input Power Range Note 5 LMV225 dBm dBV LMV226 dBm dBV LMV228 dBm dBV www national com 2 7 DC and AC Electrical Characteristics Continued Unless otherwise specified all limits are guaranteed to Vpp 2 7V Ty 25 C Boldface limits apply at temperature extremes Note 4 Symbol Condition Min Typ Max Units Logarithmic Slope Note 8 900 MHz LMV225 44 0 LMV226 44 5 LMV228 44 0 1800 MHz LMV225 39 4 LMV226 41 6 LMV228 41 9 1900 MHz LMV225 38 5 nde LMV226 41 2 LMV228 41 6 2000 MHz LMV225 38 5 LMV226 41 0 LMV228 41 2 Logarithmic Intercept Note 8 900 MHz LMV225 45 5 LMV226 24 5 LMV228 27 2 1800 MHz LMV225 46 6 LMV226 25 1 LMV228 28 2 1900 MHz LMV225 46 3 xd LMV226 24 9 LMV228 28 0 2000 MHz LMV225 46 7 LMV226 24 7 LMV228 28 0 Vour Outpu
11. S ARE IN MILLIMETERS DIMENSIONS IN FOR REFERENCE ONLY 0 5 LAND PATTERN RECOMMENDATION TOP SIDE COATING 0 050 i o BUMP SYMM BUMP A1 CORNER 0 265 0 215 SILICON TLAO4XXX Rev C NOTES UNLESS OTHERWISE SPECIFIED 1 EPOXY COATING 2 Sn 37Pb EUTECTIC BUMP 3 RECOMMEND NON SOLDER MASK DEFINED LANDING PAD 4 PIN A1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION REMAINING PINS ARE NUMBERED COUNTER CLOCKWISE 5 XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH X2 IS PACKAGE LENGTH AND X3 IS PACKAGE HEIGHT REFERENCE JEDEC REGISTRATION MO 211 VARIATION BC 4 Bump micro SMD NS Package Number TLA04AAA X1 1 014 0 030 mm X2 1 014 0 030 mm 0 600 0 075 mm LIFE SUPPORT POLICY NATIONAL S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION As used herein 1 Life support devices or systems are devices or 2 A critical component is any component of a life systems which a are intended for surgical implant support device or system whose failure to perform into the body or b support or sustain life and can be reasonably expected to cause the
12. able HI oth erwise it is in a low power consumption shutdown mode During shutdown the output will be LOW Capacitor C should be chosen sufficiently large to ensure a corner frequency far below the lowest input frequency to be measured In case of the LMV225 the corner frequency can be calculated using 3 Where Rn 500 45 pF typical With R4 18000 and 100 pF this results a corner frequency of 2 8 MHz This corner frequency is an indicative www national com Application Notes continued number The goal is to have a magnitude transfer which is sufficiently flat in the used frequency range capacitor C should be chosen significantly larger than capacitor Cy to assure a proper performance of the high resistive tap Ca pacitor C shouldn t be chosen excessively large since the RC time it introduces in combination with resistor Ro adds to the turn on time of the device The LMV226 LMV228 do not use a resistor R like the LMV225 Though a resistor is seen on the coupler side Rcoupter Therefore a similar equation holds for the LMV226 LMV228 LF corner frequency where R is replaced with the coupler output impedance gg With Rooupter 500 and C 100 pF the resulting corner frequency is 50 MHz The output voltage is proportional to the logarithm of the input power often called linear in dB Figure 3 shows the typical output voltage versus PA output power of the LMV225 setup as
13. ariation is independent of the absolute RF input signal AVo Vy APin 7 In which Vyis the slope of the curve The log conformance error is usually much smaller than the ripple due to AM modulation In case of the LMV225 LMV228 Vy 40 mV dB With AP 5 dB for CDMA AVour 200 MV pp This is valid for all Vouz Output Ripple with Additional Filtering The calculated result above is for an unfiltered configuration When a low pass filter is used by shunting a capacitor of e g Cour 1 5 nF at the output of the LMV225 LMV228 to ground this ripple is further attenuated The cut off fre quency follows from 1 fn C 2r CourtRo 8 With the output resistance of the LMV225 LMV228 Ro 19 8 KQ typical and Cour 1 5 nF the cut off frequency equals 5 36 kHz A 100 kHz AM signal then gets attenu ated by 5 36 100 or 25 4 dB The remaining ripple will be less than 20 mV With a slope of 40 mV aB this translates into an error of less than 0 5 dB Since the LMV226 has a low output impedance buffer a capacitor to reduce the ripple will not be effective Output Ripple Measurement Figure 6 shows the ripple reduction that can be achieved by adding additional capacitance at the output of the LMV225 LMV228 The RF signal of 900 MHz is AM modulated with a 100 kHz sinewave and a modulation index of 0 3 The RF input power is swept while the modulation index remains unchanged Without the output capacitor the ripple is about 20
14. ctors in tended for CDMA and WCDMA applications Power applied at its input translates to a DC voltage on the output through a linear in dB response The LMV225 detector is especially suited for power measurements via a high resistive tap while the LMV226 LMV228 are designed to be used in com bination with a directional coupler The LMV226 has an additional output voltage buffer and therefore a low output impedance The key features of the devices are shown in table 1 TABLE 1 DEVICE CHARACTERISTICS Input Range Output Application dBm Buffer LMV225 30 0 High Resistive Tap LMV226 15 15 Yes Directional Coupler LMV228 15 15 No Directional Coupler In order to match the output power range of the power amplifier PA with the range of the LMV225 s input the high resistive tap needs to be configured correctly In case of the LMV226 LMV228 the coupling factor of the directional cou pler needs to be chosen correctly HIGH RESISTIVE TAP APPLICATION The constant input impedance of the device enables the realization of a frequency independent input attenuation to adjust the LMV225 s range to the range of the PA Resistor and the 500 input resistance Rix of the device realize this attenuation Figure 1 To minimize insertion loss resis tor needs to be sufficiently large The following example demonstrates how to determine the proper value for R4 ANTENNA OUT ENABLE GND 20076033 FIGURE 1 Ty
15. failure of whose failure to perform when properly used in the life support device or system or to affect its accordance with instructions for use provided in the safety or effectiveness labeling can be reasonably expected to result in a significant injury to the user BANNED SUBSTANCE COMPLIANCE National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products Stewardship Specification CSP 9 111C2 and the Banned Substances and Materials of Interest Specification CSP 9 111S2 and contain no Banned Substances as defined in CSP 9 111S2 National Semiconductor National Semiconductor National Semiconductor National Semiconductor Americas Customer Europe Customer Support Center Asia Pacific Customer Japan Customer Support Center Support Center Fax 49 0 180 530 85 86 Support Center Fax 81 3 5639 7507 Email new feedback 9 nsc com Email europe support nsc com Email ap support 9 nsc com Email jpn feedback 9 nsc com Tel 1 800 272 9959 Deutsch Tel 49 0 69 9508 6208 Tel 81 3 5639 7560 English Tel 44 0 870 24 0 2171 www national com Fran ais Tel 33 0 1 41 91 8790 National does not assume any responsibility for use of any circuitry described no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications
16. he for mula 2 2 1 p v 1 u VrippLe Yy 1010 6 7 30 Vy 10 L06 80 IN IN Pinmax IN dBm Pinmin IN dBm 5 where Vy is the slope of the detection curve Figure 5 and is the modulation index Equation 5 can be reduced to Vy 20 LOG 6 Consequently the ripple is independent of the average input power of the RF input signal and only depends on the logarithmic slope Vy and the ratio of the maximum and the minimum input signal amplitude For CDMA the ratio of the maximum and the minimum input signal amplitude modulation is typically in the order of 5 to 6 dB which is equivalent to a modulation index p of 0 28 to 0 33 A further understanding of the equation above can be achieved via the knowledge that the output voltage Vou of the LMV225 LMV228 is linear in dB or proportional to the input power in dBm As discussed earlier CDMA has a modulation in the order of 5 to 6 dB Since the transfer is linear in dB the output voltage will vary linearly over about 5 to 6 dB in the curve Figure 5 17 www national com 866A T 9 CAW T SCCAWT LMV225 LMV226 LMV228 Application Notes continued Vour V Py dBm 20076018 FIGURE 5 Vour vs RF Input Power Piy The output voltage variation AVour is thus identical for RF input signals that fall within the linear range in dB of the detector In other words the output v
17. l Parameter Condition Units Ipp Supply Current Active Mode RFjj Ey LMV225 Vpp DC no RF Input Power Present LMV226 mA LMV228 Shutdown RF n En GND DC no RF Input Power Present Logic Low Input Level V Note 6 VuicH Ex Logic High Input Level V Note 6 toa Turn on Time Note 9 No RF Input Power LMV225 Rise Time Note 7 Present Output Loaded with 10pF Step from no Power to 0 dBm Applied Output Loaded with 10pF LMV226 LMV228 LMV225 Step from no Power to 15 dBm Applied Output Loaded with 10pF LMV226 LMV228 www national com 5 0 DC and AC Electrical Characteristics Continued Unless otherwise specified all limits are guaranteed to Vpp 5 0V 25 C Boldface limits apply at temperature extremes Note 4 Symbol Condition Min Typ Max Units Pin Input Power Range Note 5 LMV225 30 dBm 0 43 dBV 13 LMV226 15 dBm 15 28 dBV 2 LMV228 15 dBm 15 28 dBV 2 Logarithmic Slope Note 8 900 MHz LMV225 44 6 LMV226 44 6 LMV228 44 2 1800 MHz LMV225 40 6 LMV226 42 2 LMV228 42 4 mV dB 1900 MHz LMV225 39 6 LMV226 41 8 LMV228 42 2 2000 MHz LMV225 39 7 LMV226 41 6 LMV228 41 8 Logarithmic Intercept Note 8 900 MHz LMV225 47 0 LMV226 25 0 LMV228 27 7 1800 MHz LMV225 48 5 LMV226 25 7 LMV228 28 9 1900 MHz LMV225 48 2 zu LMV226 25 6 LMV228 28 7
18. l com Typical Performance Characteristics uniess otherwise specified Voo 2 7V 25 C Continued Output Variation vs RF Input Power Normalized to 25 C Output Variation vs RF Input Power Normalized to 25 C 900 MHz LMV225 900 MHz LMV226 ERROR dB ERROR dB 60 40 30 20 10 10 20 RF INPUT POWER dBm RF INPUT POWER dBm 20076012 20076059 Output Variation vs RF Input Power Normalized to 25 C Output Variation vs RF Input Power Normalized to 25 C 900 MHz LMV228 1800 MHz LMV225 3 x c Q 9 2 ui 50 40 30 20 10 0 10 20 RF INPUT POWER dBm RF INPUT POWER dBm 20076042 20076013 Output Variation vs RF Input Power Normalized to 25 C Output Variation vs RF Input Power Normalized to 25 C 1800 MHz LMV226 1800 MHz LMV228 1 5 1 0 0 5 ERROR dB ERROR dB 50 40 30 20 10 0 10 20 40 30 20 10 0 10 20 RF INPUT POWER dBm RF INPUT POWER dBm 20076060 20076043 13 www national com 86CAW 1 92 CAW T1 SCCAW T LMV225 LMV226 LMV228 Typical Performance Characteristics Uniess otherwise specified Vop 2 7V Ty 25 C Continued Output Variation vs RF Input Power Normalized to 25 C 1900 MHz LMV225 ERROR dB 40 30 20 10 0 10 RF INPUT POWER dBm 50 20076014 Output Variation vs RF Input Power Normalized to 25 C 1900 MHz LMV228
19. nt vs Supply Voltage LMV228 SUPPLY CURRENT mA SUPPLY VOLTAGE V 20076034 Output Voltage vs RF Input Power LMV226 2 50 2 25 RF INPUT POWER dBm 20076052 Supply Current vs Supply Voltage LMV226 SUPPLY CURRENT mA SUPPLY VOLTAGE V 20076051 Output Voltage vs RF Input Power LMV225 2 50 RF INPUT POWER dBm 20076005 Output Voltage vs RF Input Power LMV228 2 50 50 40 30 20 10 0 RF INPUT POWER dBm 20076035 www national com 86CAW T 9CCAIN T1 SCCAWT LMV225 LMV226 LMV228 Typical Performance Characteristics Uniess otherwise specified Vop 2 7V Ty 25 C Continued Vout V Vout Output Voltage and Log Conformance vs RF Input Power 900 MHz LMV225 2 50 2 25 m 4 2 00 E 5 3 1 75 i 2 mE T A rE im z 1 25 YN S o 1 00 1 id 0 75 2 os h EA EIER 0 00 M 5 50 40 30 20 10 0 10 20 RF INPUT POWER dBm 20076006 Output Voltage and Log Conformance vs RF Input Power 900 MHz LMV228 2 50 2 25 2 00 1 75 i Ls PS E 1 25 NYS ad p 7 ost Yl RF INPUT POWER dBm 20076036 Output Voltage and Log Conformance vs RF Input Power 1800 MHz LMV226 2 50 2 25 2 00 1 75 1 50 1 25 1 00 0 75 0 50 0 25 RF INPUT POWER dBm 20076054
20. pical LMV225 Application with High Resistive Tap Suppose the useful output power of the PA ranges up to 31 dBm As the LMV225 can handle input power levels up to 0 dBm should realize a minimum attenuation of 31 0 31 dB The attenuation realized by and the effective input resistance R n of the detector equals R 20 Tle Agp 201 31dB Solving this expression for R4 using that Rij 500 yields 3t R4 1020 1 Ry 211020 1 50 17240 2 In Figure 1 is set to 18000 resulting in an attenuation of 31 4 dB DIRECTIONAL COUPLER APPLICATION The LMV226 LMV228 also has a 50Q input resistance How ever its input range differs compared to the LMV225 i e 15 dBm to 15 dBm If a typical attenuation of a directional coupler is 20 dB the LMV226 LMV228 can be directly con nected via the directional coupler to the PA without the need of additional external attenuator Figure 2 Different PA ranges can be configured using couplers with other coupling factors ANTENNA LMV226 LMV228 A1 B2 ENABLE GND 20076046 FIGURE 2 Typical LMV226 LMV228 Application with Directional Coupler SHUTDOWN FUNCTIONALITY The LMV225 LMV226 LMV228 RF Ey pins have 2 func tions combined e Enable Shutdown Power input The capacitor C and the resistor Figure 1 and Figure 2 separate the DC shutdown functionality from the AC power measurement The device is active when En
21. r in dB power detection range Output voltage range 0 2 to 2V Logic low shutdown Multi band operation from 450 MHz to 2000 MHz Accurate temperature compensation micro SMD package 1 0 mm x 1 0 mm x 0 6 mm Applications m CDMA RF power control m WCDMA RF power control m CDMA2000 RF power control m PA modules Typical Application LMV225 ANTENNA ENABLE GND 20076001 LMV226 LMV228 ANTENNA LMV226 LMV228 A1 B2 ENABLE 2 10 ko GND 20076046 2004 National Semiconductor Corporation DS200760 www national com GINS Ul VINQOM PUE VINGO 40 10 99 9q JOMOd dY 8CCAW T 9CCAW l GSCCAWT LMV225 LMV226 LMV228 Absolute Maximum Ratings note 1 If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage Vpp GND ESD Tolerance Note 2 Human Body Model Machine Model Storage Temperature Range 2 7 DC and AC Electrical Characteristics Unless otherwise specified all limits are guaranteed to Vpp 2 7V 25 C Boldface limits apply at temperature extremes Junction Temperature Note 3 150 C Max Mounting Temperature Infrared or convection 20 sec 235 C Operating Ratings Note 1 6 0V Max Supply Voltage 2 7V to 5 5V 2000V Temperature Range 40 C to 85 C 200V RF Frequency Range 450 MHz to 2 GHz 65 C to 150 C
22. t Voltage No RF Input Power LMV225 214 350 Present LMV226 223 350 mV LMV228 228 350 lout Output Current LMV226 Only 4 5 5 3 mA Sourcing Sinking Rout Output Impedance LMV225 LMV228 only no RF Input 19 8 29 Power Present 34 e Output Referred Noise RF Input 1800 MHz 10 dBm for 700 LMV225 and 5 dBm for LMV226 LMV228 Measured at nv 10 kHz www national com 86CAW T 92CAW T SCCAW T LMV225 LMV226 LMV228 2 7 DC and AC Electrical Characteristics continued Unless otherwise specified all limits are guaranteed to Vpp 2 7V Ty 25 C Boldface limits apply at temperature extremes Condition Min Note 4 Symbol Parameter Variation Due to Temperature 900 MHz RF 0 dBm Referred to 25 C 900 MHz RF 15 dBm Referred to 25 C LMV225 LMV226 LMV228 1800 MHz RF 0 dBm Referred to 25 C LMV225 1800 MHz RF n 15 dBm Referred to 25 C 1900 MHz RF 0 dBm Referred to 25 C LMV226 LMV228 LMV225 1900 MHz 15 dBm Referred to 25 C 2000 MHz RF 0 dBm Referred to 25 C 2000 MHz RFn 15 dBm Referred to 25 C LMV226 LMV228 LMV225 LMV226 0 0 29 LMV228 0 27 0 65 5 0 DC and AC Electrical Characteristics Unless otherwise specified all limits are guaranteed to Vpp 5 0V T 25 C Boldface limits apply at temperature extremes Note 4 Symbo
23. z LMV225 2 50 2 25 5 2 00 3 5 is W pc 1 50 a 4 1 25 1 00 27 0 75 0 50 0 00 RF INPUT POWER dBm 20076009 Output Voltage and Log Conformance vs RF Input Power 2000 MHz LMV228 T Sz 4 e fd a 50 40 30 20 10 0 10 20 RF INPUT POWER dBm 20076039 www national com BCCAIN T 9 CAW V SCCAWT LMV225 LMV226 LMV228 Typical Performance Characteristics uniess otherwise specified Vop 27V Ty 25 C Continued Logarithmic Slope vs Frequency LMV225 47 46 40 C 45 mm SLOPE mV dB A N 400 800 1200 1600 2000 FREQUENCY MHz 20076010 Logarithmic Slope vs Frequency LMV228 44 5 SLOPE mV dB A N 2 400 800 1200 1600 2000 FREQUENCY MHz 20076040 Logarithmic Intercept vs Frequency LMV226 23 0 23 5 24 0 24 5 25 0 INTERCEPT dBm 25 5 26 0 26 5 400 800 1200 1600 2000 FREQUENCY MHz 20076058 Logarithmic Slope vs Frequency LMV226 SLOPE mV dB 9 400 800 1200 1600 2000 FREQUENCY MHz 20076057 Logarithmic Intercept vs Frequency LMV225 INTERCEPT dBm 400 800 1200 1600 2000 FREQUENCY MHz 20076011 Logarithmic Intercept vs Frequency LMV228 25 5 INTERCEPT dBm 400 800 1200 1600 2000 FREQUENCY MHz 20076041 www nationa

NATIONAL SEMICONDUCTOR LMV225/LMV226/LMV228 Manual

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