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NATIONAL SEMICONDUCTOR LM7341 Manual

1. 10k 100k 1M FREQUENCY Hz 20206046 CMRR vs Frequency CMRR dB FREQUENCY Hz 20206043 Open Loop Frequency Response with Various Temperatures Open Loop Frequency with Various Resistive Load 140 GAIN dB PHASE 1k 100k 1M 10M 100M FREQUENCY Hz 20206045 PHASE GAIN dB 10k 100k 1M FREQUENCY Hz 20206047 PSRR vs Frequency PSRR dB 10 100 1k 10k 100k 1M FREQUENCY Hz 20206041 www national com 12 20 V DIV VOLTAGE NOISE nV 4 Hz PSRR vs Frequency PSRR dB 10 100 1k 10k 100k 1M FREQUENCY Hz 20206042 Large Signal Step Response 200 us DIV 20206052 Input Referred Noise Density vs Frequency 1000 m 100 100 Hit HII 10 CURRENT NOISE pA Hz 1 10 100 1k FREQUENCY Hz 20206049 100 mV DIV VOLTAGE NOISE nV Hz VOLTAGE NOISE nV 4 Hz Small Signal Step Response 2 us DIV 20206051 Input
2. 25 C V 2 7V V OV Voy 0 5V Vour 1 35V and gt 1 MO to 1 35V Boldface limits apply at the temperature extremes Vom 0 5V and 2 2V Units i i 1 Tm d 120 150 Ps mV from 120 either rail 150 E www national com Gain Bandwidth f 100 kHz R 100 Input Referred Voltage Noise Density f 1 kHz Parameter Conditions Min Note 6 Propagation Delay oe Overdrive 1V Note 7 A fere D 5V Electrical Characteristics Unless otherwise specified all limits guaranteed for T 25 C V 5V V 5V Voy Vour OV and R gt 1 to OV Boldface limits apply at the temperature extremes Vos TCVo5 lout SR GBW Conditions Input Offset Voltage Input Offset Voltage Temperature Drift Input Bias Current Input Offset Current 4 5V and Voy 4 5V 5 lt o i a Vom 4 5V 4 5V and Voy 4 5V lt lt o o I I B al lt Typ Max Units Note 5 Note 6 MHz nVA Hz pA Hz dB us us us Typ Max Units Note 5 Note 6 nA 35 70 80 50 Common Mode Rejection Ratio 5V S Voy S 3V 84 112 82 dB 5V lt Voy S 5V 72 92 70 Power Supply Rejection Ratio 2 7V S Vs lt 30V Voy 4 5V 86 106 n dB 84 Common Mode Voltage Range OMAR gt 65 dB Tas 59 50 53 Open Loop Voltage Gain 4 Vo S 4V 20 110 12 V mV Ri 10
3. National Semiconductor October 13 2008 LM7341 Rail to Rail Input Output 15V 4 6 MHz GBW Operational Amplifier in SOT 23 Package General Description The LM7341 is a rail to rail input and output amplifier in a small SOT 23 package with a wide supply voltage and tem perature range The LM7341 has a 4 6 MHz gain bandwidth and a 1 9 volt per microsecond slew rate and draws 0 75 mA of supply current at no load The LM7341 is tested at 40 C 125 C and 25 C with modern automatic test equipment Detailed performance specifica tions at 2 7V 5V and 15V and over a wide temperature range make the LM7341 a good choice for automotive in dustrial and other demanding applications Greater than rail to rail input common mode range with a minimum 76 dB of common mode rejection at 15V makes the LM7341 a good choice for both high and low side sensing applications LM7341 performance is consistent over a wide voltage range making the part useful for applications where the supply volt age can change such as automotive electrical systems and battery powered electronics The LM7341 uses a small SOT23 5 package which takes up little board space and can be placed near signal sources to reduce noise pickup Typical Performance Characteristics Open Loop Frequency Response GAIN dB PHASE 100k FREQUENCY Hz 1M 202
4. to OV Output Voltage Swing 10 to OV 150 High Vip 100 mV 200 R 2 to OV 170 300 Vip 100 mV 400 mV from Output Voltage Swing R 10 kQ to OV 150 either rail Low Vip 100 mV 200 2 to OV 210 300 Vip 100 mV 400 Output Current Sourcing Vour 5V 11 Vip 200 mV ae mA Sinking Vour 5V 12 Vip 200 mV Supply Current Vom 4 5V and Voy 4 5V 0 65 1 0 14 mA i A lt 4 o www national com LM7341 Note 6 Note 5 Note 6 on s 15V Electrical Characteristics Unless otherwise specified all limits guaranteed for T 25 C V 15V V 15V Voy Vour OV and R gt 1 to OV Boldface limits apply at the temperature extremes Symbol Parameter Conditions Min Typ Max Units Note 6 Note 5 Note 6 Vos Input Offset Voltage 14 5V and Voy 14 5V 4 4 5 TCVos Input Offset Voltage Temperature Drift lg Input Bias Current Vom 14 5V 250 110 300 nA 40 80 90 los Input Offset Current 14 5V and Voy 14 5V a CMRR Common Mode Rejection Ratio 15V lt Voy S12V 84 115 50 15V lt Voy lt 15V 78 100 76 PSRR Power Supply Rejection Ratio 2 7V lt Vs S 30V Voy 14 5V 86 106 P dB a 3 lt lt o H N uV C lt lt 1 I a lt dB 84 CMVR Common Mode Voltage Range CMRR gt 80 dB 15 ge Bang gt a V 159 153 Avo Open Loop Voltage Gain 13
5. 10 97 1 19 1 02 0060 001 cy 0 15219 038 Am il C3 004 toric T Ny 5x Cy 0 002 006 0 440 096 0 05 0 151 j SEATING 0 8 TYP 025 PLANE TYP 008 10 210 c AO 0 635 O c AO jm c 0 36 0 55 TYP CONTROLLING DIMENSION IS INCH VALUES IN ARE MILLIMETERS DIMENSIONS IN FOR REFERENCE ONLY MFOSA Rev D 5 Pin SOT 23 NS Package Number MF05A www national com 18 Notes www national com LyEZINT LM7341 Rail to Rail Input Output 15V 4 6 MHz GBW Operational Amplifier in SOT 23 Package Notes For more National Semiconductor product information and proven design tools visit the following Web sites at Amplifiers www national com amplifiers LVDS Power Management Switching Regulators www national com switehers LDOs lwww nationalcomido LED Lighting wwna onacomled O PowerWise www national com powersise ND ional AAA po Serial Digital Interface SDI www national com sdi Temperature Sensors www national com tempsensors Wireless PLL VCO www national com wireless THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION NATIONAL PRODUCTS NATIONAL MAKES NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS PUBLICATION AND RESERVES THE RIGHT TO MAKE CHANGES TO SPECIFICATIONS
6. One method often used to reduce the nose is to lower the signal impedance which re duces the noise pickup In this configuration the amplifier usually requires 30 dB 40 dB of gain at bandwidths higher than most low power CMOS parts can achieve The LM7341 offers the tiny package higher bandwidths and greater out put drive capability than other rail to rail input output parts can provide for this application LM7341 AS A COMPARATOR The LM7341 can also be used as a comparator and provides quite reasonable performance Note however that unlike a typical comparator an op amp has a maximum allowed dif ferential voltage between the input pins For the LM7341 as stated in the Absolute Maximum Ratings section this maxi mum voltage is Vy Differential 15V Beyond this limit even for a short time damage to the device may occur As an inverting comparator at Vs 30V and 1V of overdrive there is typically 12 us of propagation delay At Vs 30V and 50 mV of overdrive there is typically 17 us of propagation de lay Voc Vout 20206054 FIGURE 1 Inverting Comparator Similarly a non inverting comparator at Vs 30V and 1V of overdrive there is typically 12 us of propagation delay At Vs 30V and 50 mV of overdrive there is typically 17 us of propagation delay Voc Vout 20206055 FIGURE 2 Non Inverting Comparator COMPARATOR WITH HYSTERESIS The basic comparator configuration may oscillate
7. To minimize this error it is best to use low resistor values on the inputs 30V Vout Vaz Var 0 14 975 15 025 VIN Vgur LOW Voc Ry Vaz Ro R3 20206056 FIGURE 3 Inverting Comparator with Hysteresis www national com 16 NON INVERTING COMPARATOR WITH HYSTERESIS Anon inverting comparator with hysteresis requires a two re sistor network and a voltage reference V gr at the inverting input When V y is low the output is also low For the output to switch from low to high Vi must rise up to Vy where Vin is calculated by Vint R Vegr Ro Veer When Vin is high the output is also high to make the com parator switch back to it s low state Vi must equal VpRef before V will again equal Vref Viy can be calculated by VREF 15V O VouT HIGH Vout LOW Vcc VIN 1 R2 Ri VA VREF Va VREF R4 R2 VIN 2 FIGURE 4 Non Inverting Comparator with Hysteresis OTHER SOT 23 AMPLIFIERS The LM7321 is a rail to rail input and output amplifier that can tolerate unlimited capacitive load It works from 2 7V to 15V and across the 40 C to 125 C temperature range It has 20 MHz gain bandwidth and is available in both 5 Pin SOT 23 and 8 Pin SOIC packages The LM6211 is a 20 MHz part with CMOS input which runs on 5V to 24V single supplies It has rail to rail output and low noise The LMP7701 is a rail to rail input and output precision part with an input voltage offset under 220 microvolts and low
8. 0 25 30 35 40 Vs V 20206021 ls VS Vem 0 75 0 65 0 6 0 55 20206025 0 85 0 8 0 75 0 7 0 65 0 6 0 55 0 5 20 15 10 5 0 5 10 15 20 Vom V 20206027 www national com 10 ls VS Von Vom V 0 5V ls mA 0 5 10 15 20 25 30 35 40 Vs V 20206028 Positive Output Swing vs Supply Voltage 0 5 0 4 0 3 0 2 Vout FROM RAIL V 0 1 20206036 Negative Output Swing vs Supply Voltage Vout FROM RAIL V 20206038 ls VS Vem Vom V 0 5V MAN EM Pa NN W 125 C AN E ia 5 10 15 20 25 30 35 40 Vs V 20206029 Positive Output Swing vs Supply Voltage 0 25 0 2 ee 5 0 1 5 gt a m E m 2 A Z nid 0 0 10 20 30 40 Vg V 20206037 Negative Output Swing vs Supply Voltage 0 25 0 2 0 15 0 1 Vour FROM RAIL V 20206039 11 www national com LM7341 Open Loop Frequency with Various Capacitive Load 140 120 GAIN dB PHASE 3 1k 100k 1M 10M 100M FREQUENCY Hz 20206044 Open Loop Frequency with Various Supply Voltage GAIN dB PHASE
9. 06046 Features Vg 15V T 25 C typical values m Tiny 5 pin SOT 23 package saves space m Greater than rail to rail input CMVR 15 3V to 15 3V m Rail to rail output swing 14 84V to 14 86V m Supply current 0 7 mA m Gain bandwidth 4 6 MHz m Slew Rate 1 9 V us m Wide supply range 2 7V to 32V m High power supply rejection ratio 106 dB m High common mode rejection ratio 115 dB m Excellent gain 106 dB m Temperature range 40 C to 125 C m Tested at 40 C 125 C 25 C at 2 7V 5V and 15V Applications m Automotive m Industrial robotics m Sensor output buffers m Multiple voltage power supplies m Reverse biasing of photodiodes m Low current optocouplers m High side sensing m Comparator m Battery chargers m Test point output buffers m Below ground current sensing Open Loop Frequency Response GAIN dB PHASE 10k 100k 1M FREQUENCY Hz 20206047 2008 National Semiconductor Corporation 202060 www national com oDexoed Z LOS U jeuonejedo MA9 ZHIN 9 r AGL indino nndul 1 LpEZINTT LM7341 Absolute Maximum Ratings note 1 If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications ESD Tolerance Note 2 Human Body Model Machine Model Charg
10. 30 35 40 Vs V 20206012 Vos mV Vos mV Vos mV Vos VS Vey Unit 1 20 15 10 0 2 10 15 20 20206010 Vos VS Vey Unit 3 0 9 0 85 40 C 08 25 C 0 75 0 7 85 C 0 65 125 C 0 6 0 55 Vs 15V 20 45 10 5 0 5 10 15 20 Vem V 20206005 Vos vs Vs Unit 2 0 5 10 15 2 25 30 35 40 Vs V 20206013 www national com Ibias nA Vos vs Vs Unit 3 Vos vs Vs Unit 1 Vom V 0 5V Vos mV Vos mV 0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 Vs V Vs V 20206014 20206015 Vos vs Vs Unit 2 Vos vs Vs Unit 3 Vom V 0 5V Vos mV Vos mV 0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 Vs V Vs V 20206016 20206017 Ibias VS Vom Ibias VS Vom Ibias nA 20206018 20206019 www national com LM7341 Ibias nA IBiAs nA Is mA Ibias VS Vem 20206020 0 5 10 15 20 25 30 35 40 Vs V 20206024 ls VS Von 0 75 0 7 0 65 0 6 0 55 20206026 IBiAs nA Is mA Is mA Ibias VS Vs Vom V 0 5V 100 110 0 5 10 15 2
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12. Referred Noise Density vs Frequency N lt e Ww 0 2 kK 2 x x 2 o 1k FREQUENCY Hz 20206048 Input Referred Noise Density vs Frequency N L lt amp W 0 2 x x 2 o 1 10 100 4k 10k 100k FREQUENCY Hz 20206050 13 www national com LM7341 THD N vs Frequency THD N dB 100k 80 10 100 1k 10k FREQUENCY Hz 20206053 Application Information GENERAL INFORMATION Low supply current and wide bandwidth greater than rail to rail input range full rail to rail output good capacitive load driving ability wide supply voltage and low distortion all make the LM7341 ideal for many diverse applications The high common mode rejection ratio and full rail to rail in put range provides precision performance when operated in non inverting applications where the common mode error is added directly to the other system errors CAPACITIVE LOAD DRIVING The LM7341 has the ability to drive large capacitive loads For example 1000 pF only reduces the phase margin to about 30 degrees POWER DISSIPATION Althoug
13. V lt Vo S 13V 25 200 15 V mV R 10 to OV Vout Output Voltage Swing R 10 kQ to OV 135 300 High Vip 100 mV 400 mV from Output Voltage Swing 10 to OV 160 300 either rail Low p 100 mV 400 lout Output Current Sourcing Vour 15V 5 10 Note 4 Vip 200 mV 3 mm mA Sinking Vour 15V 13 Vip 200 mV ls Supply Current 14 5V and Voy 14 5V A 1 3 e Input Referred Voltage Noise Density f 1 kHz 8 nV Hz in Input Referred Voltage Noise Density f 1 kHz o pAA Hz THD N Total Harmonic Distortion Noise f 10 kHz s dB teo Propagation Delay Overdrive 50 mV Note 7 s Overdive tViNoe7 _ www national com 4 Units 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 For guaranteed specifications and the test conditions see the Electrical Characteristics Note 2 Human Body Model applicable std MIL STD 883 Method 3015 7 Machine Model applicable std JESD22 A115 A ESD MM std of JEDEC Field Induced Charge Device Model applicable std JESD22 C101 C ESD FICDM std of JEDEC Note 3 Applies to both single supply and split supply operation Continuous short circuit operation at elevated ambient temperature can result in exceeding the maximum allowed junction temperature
14. e mA 20206033 20206030 Output Swing vs Sinking Current Output Swing vs Sourcing Current 5V HH Vs 1no A A WOH Isource mA 20206034 20206031 Output Swing vs Sinking Current Output Swing vs Sourcing Current 100 10 40 C 125 C 85 C 5 0 1 Vs 15V 0 01 110 A A WOU A A A WONI A Isink MA Isource MA 20206035 20206032 www national com PERCENTAGE Vos mV Vos mV Vos Distribution 20206040 20206004 20206006 Vos mV Vos mV VOS mV Vos VS Vey Unit 1 20206003 20206008 20206007 www national com LyEZINT Vos VS Unit 3 LM7341 Vos mV 20206011 Vos VS Unit 2 Vos mV Vem V 20206009 Vos VS Vg Unit 1 Vem V 0 5V 0 5 10 15 20 25
15. e Device Model Vin Differential Voltage at Input Output Pin Supply Voltage Vs V V Input Current Output Current Note 3 2 7V Electrical Characteristics Vos Input Offset Voltage TCVos Input Offset Voltage Temperature Drift lg Input Bias Current los Input Offset Current CMRR Common Mode Rejection Ratio PSRR Power Supply Rejection Ratio CMVR Common Mode Voltage Range AvoL Open Loop Voltage Gain Vout Output Voltage Swing High Output Voltage Swing Low lout Output Current ls Supply Current sn V 0 3V V 180 CMRR gt 60 dB Power Supply Current 25 mA Soldering Information Infrared or Convection 20 sec 235 C Wave Soldering Lead Temp 10 sec 260 C d Storage Temperature Range 65 to 150 C 209 Junction Temperature Note 4 150 C 200V 1000 Operating Ratings note 1 15V 0 3V Supply Voltage Vs V V 2 5V to 32V Temperature Range Note 4 40 C to 125 C 10 mA Package Thermal Resistance 20 mA 5 Pin SOT 23 325 C W Typ Note 5 flask 6 OV Voy lt 1 0V OV lt Voy 2 7V 27V lt V4 S 30V Vom 0 5V 0 3 0 5V V 2 2V 5 R 10 to 1 35V R 10 to 1 35V p 100 mV 2 to 1 35V 100 mV 10 to 1 35V 100 mV ERU 35V ourcing Vour OV p 200 mV Sinking Vour OV p 200 mV Vom 0 5V and Voy 2 2V 1V Step Unless otherwise specified all limits guaranteed for
16. ermore the low profile can help in height limited designs such as consumer hand held remote controls sub notebook computers and PCMCIA cards An additional advantage of the tiny package is that it allows better system performance due to ease of package place ment Because the tiny package is so small it can fit on the board right where the op amp needs to be placed for optimal performance unconstrained by the usual space limitations This optimal placement of the tiny package allows for many system enhancements not easily achieved with the con straints of a larger package For example problems such as System noise due to undesired pickup of digital signals can be easily reduced or mitigated This pick up problem is often caused by long wires in the board layout going to or from an op amp By placing the tiny package closer to the signal source and allowing the LM7341 output to drive the long wire the signal becomes less sensitive to such pick up An overall reduction of system noise results Often times system designers try to save space by using dual or quad op amps in their board layouts This causes a com plicated board layout due to the requirement of routing several signals to and from the same place on the board Using the tiny op amp eliminates this problem Additional space savings parts are available in tiny packages from National Semiconductor including low power amplifiers precision voltage references and voltage regulato
17. h the LM7341 has internal output current limiting shorting the output to ground when operating on a 30V pow er supply will cause the op amp to dissipate about 350 mW This is a worst case example In the 5 pin SOT 23 package the higher thermal resistance will cause a calculated rise of 113 C This can raise the junction temperature to above the absolute maximum temperature of 150 C Operating from split supplies greatly reduces the power dis sipated when the output is shorted Operating on 15V sup plies can only cause a temperature rise of 57 C in the 5 pin SOT 23 package assuming the short is to ground WIDE SUPPLY RANGE The high power supply rejection ratio PSRR and common mode rejection ratio CMRR provide precision performance when operated on battery or other unregulated supplies This advantage is further enhanced by the very wide supply range 2 5V 32V offered by the LM7341 In situations where highly variable or unregulated supplies are present the excellent PSRR and wide supply range of the LM7341 benefit the sys tem designer with continued precision performance even in such adverse supply conditions SPECIFIC ADVANTAGES OF 5 Pin SOT 23 TinyPak The obvious advantage of the 5 pin SOT 23 TinyPak is that it can save board space a critical aspect of any portable or miniaturized system design The need to decrease overall System size is inherent in any handheld portable or lightweight system application Furth
18. noise It has 2 5 MHz bandwidth and works on 2 7V to 12V supplies Vcc 30V R2 12 1 KQ Vine Ro Voc R4 R The hysteresis of this circuit is the difference between Vy and Delta Vin VccR R For example to achieve 50 mV of hysteresis when Vcc 30V set R 200 and R 12 1 O Vour 20206057 30V VOUT VIN2 VIN 1 14 975 15 025 VIN 20206058 SMALLER SC70 AMPLIFIERS The LMV641 is a 10 MHz amplifier which uses only 140 micro amps of supply current The input voltage offset is less than 0 5 mV The LMV851 is an 8 MHz amplifier which uses only 0 4 mA supply current and is available in the smaller SC70 package The LMV851 also resists Electro Magnetic Interference EMI from mobile phones and similar high frequency sources It works on 2 7V to 5 5 V supplies Detailed information on these and a wide range of other parts can be found at www national com 17 www national com LM7341 Physical Dimensions inches millimeters unless otherwise noted 075 0 fe 4 81 1 PKG SYMM I 64102 2 59 1 y 1 ET 063 003 Sur 1 620 071 5X 039 5X 027 i 10 82 F Cs 0375 0 953 LAND PATTERN RECOMMENDATION 0375 0 9531 R 004 MIN TYP 10 1 ane R 004 MIN TYP 10 21 10 1 038 047 040 3 GAGE PLANE
19. of 150 C Note 4 The maximum power dissipation is a function of T max The maximum allowable power dissipation at any ambient temperature is Pp Tax TAJ 4 All numbers apply for packages soldered directly unto a PC board Note 5 Typical values represent the most likely parametric norm as determined at the time of characterization Actual typical values may vary over time and will also depend on the application and configuration The typical values are not tested and are not guaranteed on shipped production material Note 6 All limits are guaranteed by testing or statistical analysis Note 7 The maximum differential voltage between the input pins is Vy Differential 15V Connection Diagram 5 Pin SOT 23 1 Br u OUTPUT IB NON INVERTING 3 4 INVERTING INPUT INPUT 20206002 Top View Ordering Information Part Number Package Marking Transport Media NSC Drawing LM7341MF 1k Units Tape and Reel 5 Pin SOT 23 LM7341MFE AV4A 250 Units Tape and Reel MFO5A LM7341MFX 3k Units Tape and Reel 5 www national com Output Swing vs Sinking Current Output Swing vs Sourcing Current Typical Performance Characteristics 2 10 1 10 100 0 1 0 01 Isourc
20. or produce a noisy output if the applied differential input voltage is near the comparator s offset voltage This usually happens when the input signal is moving very slowly across the comparator s switching threshold This problem can be prevented by the addition of hysteresis or positive feedback 15 www national com LM7341 INVERTING COMPARATOR WITH HYSTERESIS The inverting comparator with hysteresis requires a three re sistor network that is referenced to the supply voltage Vcc of the comparator as shown in Figure 3 When Vy at the in verting input is less than V the voltage at the non inverting node of the comparator Vin lt Va the output voltage is high for simplicity assume switches as high as Voc The three network resistors can be represented as R IR in series with The lower input trip voltage V is defined as Var VecRo Ro When Vy is greater than V4 Vi gt Va the output voltage is low very close to ground In this case the three network re Vcc 30V sistors can be presented as R IIR in series with R The upper trip voltage V4 is defined as Voc Ry R IIR The total hysteresis provided by the network is defined as Delta Va V4i For example to achieve 50 mV of hysteresis when Voc 30V set R 4 02 kQ R 4 02 kO and R 1 21 MQ With these resistors selected the error due to input bias current is ap proximately 1 mV
21. re devices which a are intended for surgical implant into the body or b support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness National Semiconductor and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation All other brand or product names may be trademarks or registered trademarks of their respective holders CopyrightO 2008 National Semiconductor Corporation For the most current product information visit us at www national com National Semiconductor National Semiconductor Europe National Semiconductor Asia National Semiconductor Japan Americas Technical Technical Support Center Pacific Technical Support Center Technical Support Center Support Center Email europe support nsc com Email ap support Q9 nsc com Email jpn feedback 9 nsc com Email support Q nsc com German Tel 49 0 180 5010 771 Tel 1 800 272 9959 English Tel 44 0 870 850 4288 www national com
22. rs LOW DISTORTION HIGH OUTPUT DRIVE CAPABILITY The LM7344 offers superior low distortion performance with atotal harmonic distortion plus noise of 66 dB at f 10 kHz The advantage offered by the LM7341 is its low distortion levels even at high output current and low load resistance www national com 14 Typical Applications HANDHELD REMOTE CONTROLS The LM7341 offers outstanding specifications for applications requiring good speed power trade off In applications such as remote control operation where high bandwidth and low pow er consumption are needed The LM7341 performance can easily meet these requirements OPTICAL LINE ISOLATION FOR MODEMS The combination of the low distortion and good load driving capabilities of the LM7341 make it an excellent choice for driving opto coupler circuits to achieve line isolation for modems This technique prevents telephone line noise from coupling onto the modem signal Superior isolation is achieved by coupling the signal optically from the computer modem to the telephone lines however this also requires a low distortion at relatively high currents Due to its low distor tion at high output drive currents the LM7341 fulfills this need in this and in other telecom applications REMOTE MICROPHONE IN PERSONAL COMPUTERS Remote microphones in Personal Computers often utilize a microphone at the top of the monitor which must drive a long cable in a high noise environment

NATIONAL SEMICONDUCTOR LM7341 Manual

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