Hi guys.
i want to ask your opinion for amplifier circuit to use with my tc4013 hydrophone. i have problem in designing the circuit since i couldn't find any amplifier circuit to be used with tc4013. if have, please kindly attach the link or file of schematic diagram here.
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Hydrophone TC4013
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XTR115 VREG min and max cap size
I have a design that needs a 3V supply therefore I'm feeding VREG into a 3V LDO regulator.
I don't see in the data sheet any indication as to the size of the cap across the 5V VREG pin, I have a 100nF there at the moment but the regulator wants a 1uF.
What is the range of capacitance allowed on that pin? I see that VREF has some info for that but nothing about VREG.
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LM2903, output current
Dear Specialists,
My customer is considering LM2903 and has a question.
Could you please advise?
According to the datasheet P.3 , output current is 20mA.
What's the difference between output voltage?
I appreciate your great help.
Best regards,
Shinichi
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How to reduce the offset
Hi,
I need an amplifier, differential in, differential out, three ranges 80V, 8V and 2V, common mode range of +-400V, 400M Input Impedanz. I found an solution, but the Offset is very high expecially in the 2V range. How can I fix that?
I built 4 boards, the Offsets are very different, no idea why.
Here the results.
Version | Offset 2V Bereich | Offset 8V Bereich | Offset 80V Bereich |
Proto mit OPA211K | -120mV | -29.9mV | -3.8mV |
01 mit OPA211K | -433.9mV | -109.3mV | -11.08mV |
02 mit LME4999 | 431mV | 110.62mV | 10.65mV |
03 mit LME4999 | -32mV | -8.6mV | -0.82mV |
I am not sure which op-amp is good for the servo stage.
I also need a very high capacitor to stop oscillations of the servo loop, here I need also some help.
Here my schematics:
Thanks for helping out.
With best regards
Gerhard
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LM2903PWR Hand soldering conditon
Hi,
My customer is using LM2903PWR.
He wants to know conditon of hand soldering.
Could you please let me know Hand soldering conditon of LM2903PWR?
-> Temp, period of time.
Best regards,
Shimizu
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OPA172ID output stage
Hi All,
We are using OPA172ID in one of our aerospace application. We wanted to understand if the output pin has any internal protection to ensure that the output pin voltage does not go beyond Vcc?
We have a scenario where the output pin of OPA172ID may see a voltage transient from the external world and we need to protect the IC under this condition. Your inputs on this, will help us finalise the external protection design.
Kindly do the needful.
Thanks & Regards,
C.Pradeep
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iNA326 OFFSET AND RRO BEHAVIOUR
Hi
I want to use a INA326 to generate a +/-2V signal on a CM of 2.5V. The inputs are connected to a) 0-2.5V DAC and a 1.25V ref (derived from two 10k resistor off 2.5V ref). The 2.5V ref is connected to the ref pin. The ina326 is configured with 200k/200k//1nf for a gain of 2 as per datasheet
1) Despite the input signals being stable at 1.249.9V and 1.249.9mv the output drifted by about 20mv. The reversal of the input pins fixed this problem. Why?
2) I expect the output to be able to provide +/- 2V Vref=2.5V (0.5-4.5V) but i cannot get this to work to this voltage, pin 5 voltage when measured shows the correct value so this seems to be the output buffer. The attached sim indicates what i am doing . The buffer is not connected to any load. Why would the buffer have trouble reproducing pin 5 voltage from 0.5V to 4.5V ?
Any help or insight would be apreciated
regards
Nicholas Schlensky(Please visit the site to view this file)
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TLC3702 / upper limit of capacitive load
Dear support team,
Our customer is studying TLC3702 now.
I got a question regarding TLC3702 from the customer.
So please advise me about it.
Question :
How much is the upper limit of the capacitive load of TLC3702?
I think that the device will be destroyed if capacitance of the load is too large.
So please tell me the upper limit value of the capacitive load from the viewpoint of the output current.
Best regards,
M. Tachibana
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amc1200 input common-mode voltage
Hi,
I have one quick question. is common mode input voltage of AMC1200 fixed to 0V?
In the datasheet, there is input offset voltage as +-0.2mV but i'm not sure it means range or not.
Best Regards,
Ian Lee
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AMC Gain too high
I am using the AMC1100 in an industrial instrumentation device and I am generally very impressed with the product (Survived 7kV surge testing in my circuit)
We have observed something odd though. In the attached circuit the AMC1100 are exhibiting a gain of around 8.3, We have had 5 prototype boards made from the same batch of chips, and they all display the same behaviour. Luckily for me the ADS1014 that sits downstream of the AMC1100 can sample up to the 3.3V supply rail, so I still make the product spec in terms of usable range. There seems to be no other issues. Linearity and offset both appear within spec.
Our scope is not very accurate, so the following readings were taken at DC using a stable power supply and a calibrated volt meter.
Short the AMC1100 input together, measure the differential output offset. We read 6.3mV, high, but in spec.
Apply +100mV across the inputs. Expecting 806.3 mV at the output, however we get 836mV,
Apply -100mV accross the input. Expecting -793.7mV at the output, however we get -824mV.
Supply rails are correct and stable. Input side is 5.01V. Output side is 3.27V.
Any ideas? There is simple LPF between the AMC1100 and the ADS1014. The minimum input impedance of the ADS1014 is about 70k Ohm.
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About LM5122 HO pin waveform unusual
Hi,
In my application,I will use LM5122 as a boost controller. Vin<=12V, Vout=24V, 5A, My schematic as below.
When I tested my product, I find my efficiency is about 83%, and when it have the load, the High side MOSFET Q2 is very hot. So I dected the LO and HO pin waveform as below picture. I found the LO is normal and the HO has a drop from 32V to 28V. My mosfet Vgs is about 8V. So I think my MOSFET is not fully open and the efficiency is lower.
My concer is why HO pin has below waveform? Great thx
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Tlc2272 opel loop gain frequency dependece
Dear all,
I'trying to model the frequency behavior of TLC2272 as a first order LPF. Would it be all right to consider the cut-of frequency 10KHz and Aol=35e3?
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AMC1100 Gain too high
I am using the AMC1100 in an industrial instrumentation device and I am generally very impressed with the product (Survived 7kV surge testing in my circuit)
We have observed something odd though. In the attached circuit the AMC1100 are exhibiting a gain of around 8.3, We have had 5 prototype boards made from the same batch of chips, and they all display the same behaviour. Luckily for me the ADS1014 that sits downstream of the AMC1100 can sample up to the 3.3V supply rail, so I still make the product spec in terms of usable range. There seems to be no other issues. Linearity and offset both appear within spec.
Our scope is not very accurate, so the following readings were taken at DC using a stable power supply and a calibrated volt meter.
Short the AMC1100 input together, measure the differential output offset. We read 6.3mV, high, but in spec.
Apply +100mV across the inputs. Expecting 806.3 mV at the output, however we get 836mV,
Apply -100mV accross the input. Expecting -793.7mV at the output, however we get -824mV.
Supply rails are correct and stable.
Any ideas? There is simple LPF between the AMC1100 and the ADS1014. The minimum input impedance of the ADS1014 is about 70k Ohm.
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TLV2362 input impedance
Hi,
Could you tell me what the input impedance of the TLV2362 (configured as non-inverting, unity gain) is? Ideally across the audio range of 20Hz - 20kHz or, if that is not possible, just at 1kHz.
Regards,
ac
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Noise in AC voltage measurement
Hi,
I am trying to measure AC rms voltage using microcontroller. I have attached the circuit for measurement. I am connecting a 3V step down transformer out to the input of the circuit.The feedback capacitor has been added to reduce the noise, but I am getting noise if I add this which I seen using an oscilloscope. This is getting smooth after the low pass filtering. Everything else, like clamping the voltage and all are properly happening. Do I really need to place the feedback capacitor? What are the recommended values if it is needed?
Thanks
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ECG amplifier with INA333 and OPA333
Hi there
I am currently doing a project on Localised ECG and in using TINA-TI to simulate the circuitry that I have, I seem to not get the right output or a reasonable output at all. I can't really tell why it is not working properly. Could someone please have a look at the attached file and give me your feedback? Thanks for your time in advance.
Regards,
Jeffrey(Please visit the site to view this file)
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OPA1622 disturb earhpone issue
Hi,
I used OPA1622 for LPF, follow PGA4311,a part of schematic as below(4pcs OPA1622 role as OR+/-, OL+/-). The problem is: If OPA1622 is Enabled, when a cellphone approaching, there is beep in the earphone; If OPA1622 is Shutdown or taked off from the circuit, It is ok .would you help please? Thanks.
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TLC372 How to deal with the unused pins
Hi Team,
The customer is using TLC372. And he only uses one channel. Another channel will not be used.
How deal with the unused pins? Pull up to VCC, pull down to GND,floating or any other ways?
Best Wishes,
Mickey Zhang
Asia Customer Support Center
Texas Instruments
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OPA227 floating voltage measurement
Hello,
The purpose of our system is to measure a 80VAC signal generated by an independent power supply (Totally different ground) , and convert it into a -/+ 10 Vac signal suitable to be analyzed .
This power supply is a Sinus 80VAC MAX , 400 HZ , but why have no idea about the common mode .
We wanted to try a classic difference amplifier with a Gain of 0.125 , powered by an isolated DC/DC converter but , we don’t know if the voltage on the input pins are acceptable because of common mode .
Beside we need a 1Mohm input impedance ( at least ) .
We tried this circuit but we had some oscillations noises because of the too large feedback resistance. And the internal features of this OP AMP
Do you have a better solution or another kind of OPAMP more suitable to do the JOB
Thx
Regards
CSD17585F5
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LMP7300 Reference Output Impedance
My application is a lithium battery pack for use with underwater robots, The LMP7300 is part of a circuit that detects if the battery pack is unplugged and disconnects power from the output connector to prevent damage or hazardous conditions in case this happens underwater. A Wheatstone bridge, powered by the raw 21 - 29V battery voltage, is amplified by an INA122 and used as the input to an LMP7300. The purpose of the Wheatstone bridge is to detect if the resistance of a short circuit through the connector rises above 100 ohms so that the connector can be safely de-powered.
I'm using the REF output of the LMP7300 to drive the REF input of the INA122. Based on the 0.5 mV/mA Load Regulation specification of the reference, the DC output impedance seems low enough to preserve the high CMRR of the INA122.
The problem we're seeing is that a sudden load change on the battery, and the resulting change in battery voltage, causes a significant transient on the output of the INA122 that triggers the LMP7300.
The INA122 has a gain of 20. The LMP7300 hysteresis is set to plus and minus 5 mV.
I can think of two possible causes of the problem:
- The INA122 is also powered directly from the battery voltage and the PSRR may be insufficient
- The CMRR has been compromised by the REF input drive impedance
I don't think the problem is a layout issue. The majority of the load on the battery is from BLDC motor controllers. The miniature size and dense population of the BMS board makes rework or tinkering painful. Before I start making hardware changes I was hoping to reduce the range of possibilities, it wouldn't be easy to power the INA122 from a more stable power source. I was hoping someone could comment on the suitability of using the LMP7300 REF out to drive the INA122 REF input with no buffering or filtering.
Thanks for the help!
Sheldon
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