Hi Team,
For BUF20800, what is LD and AO definition?
It look like relating control interface. but there is no description for LD and AO at BUF series.
Please let me know.
BRs,
Nate
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[BUF20800] LD, AO pin Inquiry
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LMP91000 - The LOWdown on Voltage, Current, and Resistance
So after reviewing many, many, many posts, I have seemed to have collected some conflicting information about voltage, current, and resistance in the registers and components on the LMP91000 and the complete potentiostat.
Please correct me where I am mistaken. The voltage sent to the WE is the Variable Bias that is configured in the LMP91000 register MINUS the voltage configured in the Internal Zero. So if my variable bias is set at 6% of the power supply (5.0 V), and the Internal Zero is set at 20% of the power supply, the voltage set as a bias between the WE and RE is -700 mV. Is this correct?
ALSO:
If I were to calculate the current produced at VOUT, I would take (Current at VOUT) = (Variable Bias Voltage - Internal Zero Voltage)/(RTIA Gain/RLoad)?
OR is the variable bias that is set the actual voltage bias set between the WE and RE and the Internal Zero Voltage is only relevant when reading the VOUT? Very unclear about the RTia Gain and Rload as well.
Please, as soon as humanly possible.
THANK YOU.
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OPA340 and OPA365 measuring small voltages close to lower rail
OPA340MDBVTEP and OPA365MDBVTEP
What operational limitations might there be to measure signals within 1 to 5 mV from the lower rail on the input? The amp is strapped to a gain of 24 so the output signal would be greater than 24mV. Looks like the spec sheet says output could be within 20mV of the rail? Any weird behavior in using the amp close to the rail?
Bandwidth is low. Output current is minimal.
Thanks,
Jeff
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LMP7721 input referred current noise vs frequency
I am interested in using the LMP7721 as a photodiode transimpedance amplifier where the photodiode current may be as low as 10pA. The datasheet shows the input referred current noise as 0.01pA/(Hz)1/2 at 1kHz. What is this value as a function of frequency? I am designing for a BW of 10kHz.
Thanks,
Tom
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TINA TI simulation ,strange result of opamp capacitive load of LM7321, OPA830 and LMV321
Dear Spelialists,
(1)My customer is simulating opamp capacitive load by TINA TI, but he can't get good results.
Please see attached file. (question about simulation result)
Could you please advise what is the problem.
(2)And then I made a circuit by using TIDU032C as a reference, it may be strange.
please comfirm attached file(phase margin of 10nF load between LMV321, OPA830 and LM7321)
Because the LM7321 is for unlimited capacitive load, but phase margin is quite small at only 10nF.
Could you please advise.
I appreciate your great help.
Best regards,
Shinichi
(Please visit the site to view this file)
(Please visit the site to view this file)
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TLV3404IDR
Hello, we have a question on this device. What is the input impedance please?
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Filtering LEM HO 6-P/SP33 current sensor output for TI TM4C1294
I am using LEM HO6-P/SP33 current sensor with the TI TM4C129 board. I need to have the necessary signal conditioning, filtering etc. to filter the current sensor output to get some stable output out of the ADC. Below design I am thinking for the filtering/signal conditioning. Any suggestion on which OPAMP and R, C values I should use?
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LM234 from defunct National Semiconducor
Dear TI Specialist and Forum´s members
In remote country (as Brazil) we are at bay to design circuits as components are not on one´s reach
I go to design a current source 1 mA and 2 mA for medical application
TI LM124/234/334 seems to have a perfect choice (cost, stability, one resistor to perform the job, et cetera)
But I found defunct National´s logo "M234" on the market SOIC-8 package
TI datasheet SNVS746E –MARCH 2000–REVISED MAY 2013 tells us LM234 is three-pin and not SOIC-8
Futhermore "M234" does not match with "LM234"
A single hand from your own can save my day
Thank you, Silvio Penteado
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Resistors for bias current return path for PGA204
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ADS8318 Bipolar single-ended to unipolar differential.
Hi,
I am using ADS8318 as ADC IC, in the datasheet, it lits one way convert bipolar single-ended to unipolar differential. But I doubt it, I think the part in the red circule lacks connection between output and negative input of upper OPA. Am I right?
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LMP91000 EVAL I2C using mbed ble nano uC cant get the code to work.
I keep getting a NACK back from the LMP91000 using this code blow
#include "mbed.h"
I2C i2c(p10, p8);
char data[1];
char statusAddr [1];
const int addr = 0x90; //shifted from 0x48 7bit to 8bit addr
int returnVal;
Serial pc(USBTX, USBRX);
int main() {
pc.baud(9600);
wait(5);
i2c.frequency(100000);
statusAddr[0] = 0x00;
while(1) {
i2c.write(addr, statusAddr, 1, True); //Write to register to read from
returnVal = i2c.read(addr, data, 1); //read actual data from register
pc.print("the value is :%d\r\n", returnVal); //should be getting 0 for ACK, non zero is NACK.
wait(1);
}
}if anyone is familiar using mbed would be great to know what the mistake is that I am doing. MENB is shorted pins 2/3 on the eval board.
Thanks.
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OPA365 GBW
The GBW of the OPA365 is specified at V+ = 5V on the datasheet. However, there is no information about the GBW at lower V+. The part is specified to operate from 2.2V < V+ < 5.5V. I will be operating at 3.5V. I do require a GBW of 50MHz at this supply voltage. Is there any data on the GBW at this supply voltage?
Thanks,
Dan
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Incorrect OPA209 simulation
I am testing current capability of op-amps (for the purpose of component selection) by evaluating voltage swing to rails with simulation in Cadence/OrCAD PSpice.
I do it by sweeping through a current source at the output (at 75°). For negative rail (and currents) the V2 is set to 0V.. However, I get 100% nonsense (e. g. output voltage beyond supply rails) with OPA209 and sometimes fails to run altogether
1
Green is supposed to represenr output voltage and red the swing.
The paramenter are transferred to model with
X^@REFDES %+ %- %V+ %V- %Vout @MODEL
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LMV344 unused and improperly terminated op-amps..
Hello there,
We're currently working on a design and have received boards where the third and fourth op-amp inputs have been left floating and are unused. After reading this article by Todd Toporski, it is seeming like we may have to scrap the first iteration of boards. But then upon reading the summary here on the forums by Bruce Trump, we are wondering how bad the worst case scenario will be.
It is given that we will have increased quiescent current and with that probably a higher thermal output but we would like to know by how much? Would you be able to give a worst case estimate of how much the Iq could increase versus if we went with a unity gain follower termination?
Bruce's article says that internal noise interference from same-package op amps shouldn't be too much of a worry, is that true for the LMV344?
Any comments are appreciated. Thanks so much.
-Amanda
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PGA309 calibrate Issue
Hi Team,
The customer is using PGA309EVM-USB. There are some issues when the customer calibrates the parameters.
The customer calibrates 3 ponits, those are 25℃, 85℃and 125℃, the output voltage is normal and the voltage is from 0.5V to 4.5V. And the
configuration for EEPROM is as follows.
However, when the customer calibrates another 3 ponits, those are -40℃, 25℃,and 125℃ or -40℃, 25℃ and 85℃
, the output voltage is only from 0.56V to 4.3V. And the T1~T5 registers for EEPROM are 0. The configuration for EEPROM is as follows.
Q: What is the reason? How to solve the issues?
Thanks,
Best Regards,
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about LMC7101AIM5 input
hi dear supporting team,
customer is using LMC7101AIM5 as their feedback amp in one power module, now they found the input for PIN4 is -0.7V, which is lower than -0.3V as d/s states, so this would affect long term reliability, right? btw, do we have ESD clamp diode at the input/output pin? tks!
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1NA118 Amplifier
Hi,
Trying to understand the behaviour of the 1NA118 amplifier.
When my Posive Vin is 538mV and the Negative Vin 527mV (Delta 11mV), I am getting unexpected amplification values (Rg tested 0.2K to 5K). However, when I set the Vin such that I have a differential of 22mV, with the same Rg values as previously, the results are within the expected range.
The signal is generated from a 20KHz AC source.
Could anyone help please?
Thanks
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INA188 in TIDA-01063
Dear all.
TIDA-01063 measures an AC current, but can DC be gauged with the same Rogowski method?
Regards,
PAN-M
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LMC6001A TINA model for temp drift
Hi,
A customer wants to perform temp similation for their circuit using LMC6001A by TINA-TI. However existing TINA spice model of the OP amp does not support temp coeffient of offset. Could you add the offset drift parameter to the TINA model?
Best regards,
Tetsuro
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INA118 The input noise issues
Hi Team,
The customer is using INA118. He needs to assess SNR of his system when the frequency is less than 5HZ.
Q1: Look the attachment. Is the parameter information the input voltage noise density and the current noise density for the 6.5 Electrical Characteristics of the data sheet?
Q2: If it is the input voltage noise density and the current noise density, how much is the 1/fcorner for the input voltage noise and the current noise ?
Q3: How to calculate the totla input voltage noise?
If VN is the input voltage noise density, Iin is the current noise density, RS is equivalent source resistance , fci is the frequency for the the current noise and fcv is the frequency for the input voltage noise, the total input voltage noise= root {[Vin*(1+fcv/f)]^2+0.5*[Iin(1+fci/f)*RS]^2}?
Thanks,
Best Regards,
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