↧
TL972-Q1: input impedance
↧
AMC1311: AMC1311 Output Stage
Part Number:AMC1311
Hello
I am Designing an Isolated 0-20 mA corresponding to a 0-2V Isolated signal .
I am planning to use AMC1311 Isolator in conjunction with XTR111 ( and an External P Ch MOSFET NTP2955 )
to generate a 20 mA O/P proportional to 0-2V Input to AMC1311 .
Can I use the OUTP & OUTN with a 2 uS Filter to directly connect to Vin & Set of XTR111 ;
or do I need an additional Op Amp in between as a Diff Amp .
Basic proposed Ckt is as follows :
↧
↧
INA213-Q1: TRANSIENT - PULSES in the Input supply of the Amplifier_Is it damage the Opamp
Part Number:INA213-Q1
Hi Team,
We are going to use INA213-Q or INA213AQDCKRQ1 part in our design.
We have transient pulses test case at SW_VIGN_FUEL supply. Is it affect your operational amplifier.
Refer the transient specification table below :
We have voltage limitation circuit before of that SW_VIGN_FUEL. It is generated from VIGN.
We have diode and MOV in the path.
↧
AMC1300: How to adjust the RC filter?
Part Number:AMC1300
HI Sir
I use the AMC1300 to be the shunt monitor, the total current is 40A,Shunt is 2mOhm,
during the no current flow, i will measure the output pin 6 of amc1300 about 800mv Vpkpk noise,
how to adjust the R/C Filter?
could you help to review the schematic?
&how to calculate the R/C Filter between pin2,3?
↧
INA128: Variation in voltage at Vref terminal
Part Number:INA128
Hi Team,
We are using INA128, Instrumentation Amplifier in our design to measure the voltage across a Wheatstone Bridge - Load Cell.
The load cell output terminals are connected at VIN+ and VIN- terminals of the Instrumentation Amplifier INA128.
We have used 2.5V and a resistor divider with two 12K_0.1% resistors as shown in the attachment, to apply a reference voltage of 1.25V
But when measuring, we see that 1.43V is present at VREF terminal.
Also, this reference voltage is changing whenever the load voltage across the Load cell changes.
Could you kindly help in understanding the variation in reference voltage and if it doesn't remain constant?
We are using the below relationship where we assume Vref = 1.25V.
Vout (V) = ((VIN+) - (VIN-)) * Gain + Vref
Thanks,
Denny
↧
↧
TLV9001: TLV9001 work as subtractor
Part Number:TLV9001
Team,
Now I am promoting TLV9001 to a headphone customer and expects the project to have high volume. TLV9001 is used to amplify the output singal of mic. The mic signal is differential and amplititue is around 10mVrms. Signal frequency range is around 20~10kHz.
Below is the circuit that I am thinking of now. Gain is 30. Do you have any concern of it? Or do you have better option?
Current AC couple capacitor is 4.7uF. Customer would like it to reduce to 1uF. Could I increase the resistance by 5 times to achieve that?
↧
LMH6518: LMH6518 interfacing to THS4541
Part Number:LMH6518
Hi,
I am building a differential probe and a scope with ADS 4225. I am willing to have the LMH6518 inside the probe so that it is very close to the input buffers. My thoughts are that having the DVGA away from the buffers would introduce higher noise susceptibility due to the coaxial cable(s) connecting the buffers output to the DVGA. Now, if i do keep the DVGA close to the buffers (inside the probe), i would have to connect its' output to the THS4541 (ADC driver) input using 2 different coaxial cables so that i can keep the connection differential. However, i was thinking that after the DVGA, no significant gain would be necessary and thus using single ended connection would still be acceptable. In order to use single ended connection, i would have to use only one of the LMH6518's outputs, pass it through a 50Ω coax cable and terminate it with a 50Ω resistor right at the THS4541's input. 
I have implemented a simulation circuit that has the buffers followed by a THS4541 (instead of the LMH6518) and then followed by the THS4541 (adc driver). (The LMH6518 TINA spice model is not available yet.)
The point where i have my doubts is the value of Rt which in conjunction with the Rg1+Rg2 must be 50Ω. The output CMV of the first THS4541 (replacement of the LMH6518) was set to 2.5V. However the voltage value at the point where Rt & Rg1 connect is now not 2.5V since the Rt form an attenuator with the 50Ω resistor internally in the LMH6518. Rg2 had off course to be biased to the same CMV that the Rg1 was so i used the 1.65V that you see to zero the output (diff) of the THS4541 on the right.
The snapshot of the TINA TI schematic works fine. I set the CMV of the THS4541 to 0.95V as the ADS4245 requires and i get the expected amplitude at the output.
Can you pls confirm if using such a connection between one of the LMH6518 outputs and one of the THS4541 is an acceptable way of connecting the two opamps?
I think there is something wrong in the Rt value. Its' value would be correct if the Rg2 was connected to GND but Rg2 is instead connected to 1.65V! Wha should i do there?
Any suggestions regarding the schematic?
Regards
Manos
↧
TINA-TI: TINA-TI : Receiving a "Not supported device: NSTRUMENTS. Line: #1 {OPA2376}
Part Number:TINA-TI
We are using TINA-TI to run a simulation with the OPA2376. This Op amp is included in the list of available op amps in TINA-TI. However, we get "Not supported device: NSTRUMENTS. Line: #1 {OPA2376}" when we try running a simulation. We are using Version 9.3.150.328 SF-TI.
Thank you
↧
LM6211: Maximum differential input voltage
Part Number:LM6211
Hi everyone!
I'm using an OpAmp LM6211 in non-inverting mode. Recently I've noticed a parameter in datasheet that confused me a bit. It's about Vin differential (it's absolute maximum value is +- 0.3 V). Please, can you explain to me, what restrictions does it impose on the input signals? Or maybe there're some limitations on the output signal? I understand that OpAmp is tending to make the differential voltage between inverting and non-inverting inputs equal to zero, but I suppose that in some cases this rule doesn't work.
I really appreciate any help with this issue!
↧
↧
INA240: current sensing
Part Number:INA240
Hi ,
How much is the enough slew rate and bandwidth of current sensors in FOC algorithm for:
1)Inline current sensing
2)low side current sensing
Regards, Mohammad
↧
TLV6700: Unused pin check
↧
TLV2171: why is there a large input current of AMP without power supply
Part Number:TLV2171
My customer wants to use amps for high side current sensing in the battery application. Their challenge is that when the battery goes into sleep mode, there will be undesirable current going to amps, which will cause energy loss. So they conducted the below tests for the input current of different amps when there is no power supply.
Test condition: Vcc floar, Vin=8.4V
Test results:
TLV2171：VCC=3.13V Vo=1.3V Iin=3.9mA
LM358：VCC=6.6V Vo=6.6V Iin=21.7mA
IN180：VCC=50mV Vo=0V Iin=32uA
The question is that how to explain such a high input current for TLV2171 and LM358, same as OPA2171. And is there any suggestion on how to reduce this current? They wonder whether choosing a amp with higher input resistor will help, but the input resistor of TLV2171 is already 100M ohm.
↧
LM331: Generation of harmonic signals of controlled frequency and amplitude
Part Number:LM331
Dear all,
my need is to generate an harmonic signal (sine wave) with a frequency tuned between 0 and 1 kHz and the amplitude controlled between 0 and 1 Vrms. As analogic inputs to control frequency and amplitude, I can provide current and/or voltage (dc) signals.
I am guessing to use the LM331 to control the frequency and feed the generated signal to a VCA810 (or equivalent) to control the amplitude.
What is the amplitude of the signal generated by the LM331? Does it depend somehow on the analogic input signal as the frequency (formula to calculate?) or is it constant?
Could you please confirm that this solution make sense?
Thank you
Leonardo
↧
↧
LMP7731: Shelf life
Part Number:LMP7731
Hi,
What is the recommended shelf life for LMP7731MA/NOPB? Is it okay if we use it with a lot date of Jan 2013 on a noise sensitive board without causing reliability and functionality issues?
Thanks,
Saeedeh
↧
OPA549: High current, precision amplifiers for 18bit or 20bit DAC buffering
Part Number:OPA549
Dear Power OP-AMP team, We want to drive a DC motor using 18 bit/20 bit DACs with an update rate of 2.5us, and the precision DAC signal is used to control the speed/position of a DC motor. We want to use Power OpAmp between the DAC and the motor. The DAC is 18/20 bit, is there any Power OpAmp that is low noise, and is capable of delivering 2A~8A current that we can use? we are currently evaluating Opa549-HiRel in simulation, and would like to know whether it can be used in this application, or, do you have any alternative suggestion?↧
LM358-N: Help designing cascading amplifiers: voltage subtractor outputting to a non-inverting amplifier
Part Number:LM358-N
I will preface this all with I am a mechanical engineering student that is working on an electronics project so I can use all the help you are willing to give me, ha! I have attached the two schematics. For purpose of this question I have separated the two op amps, however in the actual circuit the output of the voltage subtractor is meant to be the input for the amplifier. I have been running tests and running into problems. The voltage subtractor seems to be working well on its own, however when using Op Amp A I get a 6% error, and with B I get a 24 % error which is odd, any idea why this is? The larger question however lies with the amplifier configuration. When using this amplifier, for testing I put 50 mV in and expected a gain of 101 to 5 V, but instead I was getting a gain of 67 to an output of 3.75 V which is a 33% error. I also tried a configuration with 0.93 V in and received 3.71 V out which is a gain of 3.98, when I was expecting a gain of 5.7 which is a 20% error. For reference I am supplying the single mode op amp with 5V for Vcc. My power sources are arduino Uno's since they give a pretty constant voltage source. Again I have very minimal electronic background so any and all suggestions are greatly appreciated! Thanks in advance! 
↧
LM9044: LM9044V/NOPB
Part Number:LM9044
Please I need to ask about LM9044V/NOPB, it's classified at TI Web site as Instrumentation Amplifer but I've noticed that it is for sensors, Can I consider this part number as Sensor and Detector Interface or not?
Appreciate your fast response.
↧
↧
LM2917-N: Tolerance on Internal Zener Diode
Part Number:LM2917-N
I am using the LM2907 in a frequency to voltage configuration. My input power supply varies from 23-26V, and it is causing too large of a swing in my output voltage.
I have decided to switch to the LM2917 part instead with the internally regulated supply rail of 7.56V, but I need to know the tolerance on this so I will know the tolerance on my output. I didn't find it in the datasheet, and I opened a case but they instructed me to come here.
I am planning on using a 2K current limiting resistor on pin 6 of the device from the supply rail. Not sure if that makes a difference.
↧
LM324-N: LM324N vs LM324N/NOPB
Part Number:LM324-N
What are the differences between the Texas Instruments parts LM324N and LM324N/NOPB. They have different datasheets but are very similar. I thought it was RoHS but they both look to be RoHS compliant.
↧
INA253EVM: Suitability for LMG3411
Part Number:INA253EVM
Hello,
We have LMG3411EVM-18 daughter boards and we want to use them in closed current loop mode. We found 2 EVMs that we think can help us. These are;
· INA253EVM. We wonder about the -4V limitation mentioned in the EVM manual. Normal AC voltage will vary from 80V to -80V
· DRV421 EVM. If this EVM can do the job we would then need 3 of these modules for 3-phase system measurement....correct?
Please let us know if you think if these are appropriate choices, and whether we need to complement them with other LMG EVMs.
↧