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INA333: INA333 can measure 20uA current?
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OPA320: Input Bias Current vs Temperature
Part Number:OPA320
Hi Team,
My customers are looking for operational amplifiers with extremely low temperature drift input bias current fluctuation at Ta -10°C to 70°C.
Required specifications: max 10 pA @ 70°C
OPA320 is max 50pA at -40°C to 85°C , but it seems that there is no temperature drift up to 70°C in Figure 10. Input Bias Current vs Temperature in the data sheet.
I will ask for the following.
・ Figure 10. Expanding vertical axis of Input Bias Current vs Temperature.(Same as OPA 340 data sheet Figure 13.)
・ Input Bias Current Max. Value (Ta = -10°C to 70°C)
Best Regards,
Kenji
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PGA2500: DC offset and Pop noise issue
Part Number:PGA2500
Our customer is facing large DC offset and it crate audible pop noise when change PGA gain setting.
This is just before final device selection stage after ES1 evaluation, if this is device performance limitation they will move to another PGA.
DC servo is enable however 6 devices output pin DC offset value is following.
(PCB1) 1ch 2ch (mV)
VOUT+ 5.14 -2.7
VOUT- 4.98 -2.6
(PCB2)
VOUT+ 2.0 4.6
VOUT- 2.2 4.6
(PCB3)
VOUT+ -0.6 5.1
VOUT- -0.3 5.3
We try to eliminate input pin offset influence by Granding the terminal but no change.
And there is strong relation between pop noise level and DC offset.
Is this device failure because DC offset specification is 1mV at any gain setting on the datasheet?
Regards,
Mochizuki
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WEBENCH® Tools/OPA1664: Low pass filter ; capacitor size too big generated from Webench
Part Number:OPA1664
Tool/software: WEBENCH® Design Tools
Hi,
I am using webench to create a low pass filter (image pasted, report attached). The BOM generated by the filter seems odd to me. The feedback capacitor size (C2) in third stage and fourth stage is 1812 (4532 Metric). The rated voltage level of the capacitor is 50V. Input voltage is only +/- 2.5V. Can we select capacitor of the size 0603 or 0805 separately. 1812 (4532 Metric) size is too big and will occupy lot of estate of the PCB.
Regards,
(Please visit the site to view this file)
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Selecting a OpAmp
Hi,
I find I hard to choose a OpAmp for my project. What I need is a bipolar to unipolar OpAmp that reads ±0.1V on the input and puts out a voltage between 0 - 3.3V
Can someone help me guide me trough the datasheets of give an example OpAmp that would suite these requirements.
Thank you
Luc
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OPA192: Power up ramping
Part Number:OPA192
Hello Team,
as far as I understand the OPA192 reads the eTrim registers during power-up, correct?
Are there any requirements for the ramping of the supply voltages (+Vs, -Vs)?
E.g. is it allowed to power up the pos. rail, wait some ms and then ramp the neg. supply?
Or if any other load on the same supply causes a voltage drop would that impact OPA192 behavior, please?
Thanks and Best Regards,
Hans
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LF398-N: Power supply values
Part Number:LF398-N
Hello,
I would like to know if the LF398 will work if I connect it to a +/-12V Power Supply ?
Thank you in advance for your help
Kind regards,
Julien R.
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LM231: Minimum Pulse Width
Part Number:LM231
The data sheet does not really describe in detail the minimum pulse width that the device can see in a frequency to voltage mode. It appears that the frequency is rather low (~10k), but do we have any information on the minimum pulse width that the customer can use?
Thanks for your help with this!
Richard Elmquist
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THS7316: Looking for a VGA Splitter
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INA188: GAIN setting
Part Number:INA188
Hi,
49.9Ω is recommended as GAIN=1000.
When RG = 49.9Ω, Actual GAIN is 1003.
Otherwise, Gain range shows 1~1000 on the specification.
Gain is not guaranteed when RG is 49.9Ω.
Is it correct?
Best Regards,
Kuramochi
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INA326: INA 326 and transducer
Part Number:INA326
Hello, I have a question about INA 326 instrumentation amplifier and pressure transducer. I use a circuit from INA326 datasheet 9 page, except I don't use filtering at output of amplifier. R1=4,7k, R2=100k, so gain could be aproximetely 40-50. On the pin 5, I connect 100k resistor and 0,1uF condensator. Problem is that, when I apply pressure to my transducer voltage between data signals is 30mV. So, for my gain, output voltage could be about 1,2-1,4V, but when i check voltage with multimeter I see only 160mV, and when I applied more pressure to my transducer, voltage in the output of amplifier didnt change, still 160mV. Both, transducer and amplifier powered by Arduino, and I check voltage between amplifier output pin and common ground in the breadboard. What can be problem? I attach INA326 datasheet and my breadboard connected circuit, maybe there are some connection errors.
http://www.ti.com/lit/ds/symlink/ina326.pdf
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TIDA-00777: clarification on the "Phase error observed"
Part Number:TIDA-00777
Team,
Regarding TIDA-00777 - "Active Integrator for Rogowski Coil Reference Design With Improved Accuracy for Relays and Breakers - TIDUBY4A":
-Referring to page 24, 26, 27 and 29:
What do you mean by “Phase error observed” and how do you calculate/measure it?
What are the signals you refer to and at what point of the TIDA-00777 are they measured?
-For example:
At page 24 you mention 90 uS
At page 29 you calculate 499.7uS
What does the 90uS refer to? Are you talking about the phase error introduced by the integrator (phase error would be equal to 90°-atan(2×pi×f×RC)) ?
Where do you take into account the tolerance of the electronic components?
Thanks in advance,
Anthony
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LMC6082: as ph electrode amplifier
Part Number:LMC6082
Dear Sir/Madam,
I am working on pH electrode amplifier . Planning to use one of the op-amps "LMC6082C" or LMC662C or LMC6482 which have fA input bias current. Attached circuits and simulated results using Op-amps "LMC6082C" and "LMC662C" in TIna-TI.
LMC6082C is giving delta value between 1.8mV to 5mV for pH glass electrode source resistance 50M to 500M ohms.
LMC662C is giving delta value between 6m to 9mV for pH glass electrode source resistance 50M to 500M ohms.
In case of LMC662 input bias current of 2fA (High compared to LMC6082) , still delta is more (6m to 9mV). In case of LMC6082 input bias current of 10fA , delta is less(1.8mV to 5mV).
Please give your valuable comment.
1. Also give comment on schematic , is it better to go for proto design. Any comoponents yet to add???
2. Also which opamps is better to go for proto design.
Thanks
Srinivas
(Please visit the site to view this file)
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OPA3692: Video splitter
Part Number:OPA3692
Hi,
We are using attached design to split a composite video signal into three composite video signal (75 ohm) using OPA3692 IC. The incoming composite video signal is sent into AD8001 OPAMP IC to initially amplify the video signal. Could you please assist to confirm if the attached design is acceptable. Also let us know if you came across any designs related to Video splitter circuits using OPA3692.
Thank you & Regards,
Nishmitha
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TL441: Perform an impedance measurement
Part Number:TL441
Hi,
i need to perform an impedance measurement and i think about using the TL441-EP. I used the configuration suggested in the application information in data-sheet, but what are A2 and B2 and why i need to input the signals both in A1 and in A2 and in B1 and B2 being the two in A2 and B2 amplified by the two op-amp? How much is the gain i have to set for the op amp in A2 and B2?
Thanks for the reply
Stefano
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AMC1311: AMC1311 drop output characteristics
Part Number:AMC1311
AMC1311 instead of ACPL-C87AT test, sampling precision, high and low temperature performance test has been completed, little difference, but the output characteristics in the working voltage range when the exit is different, accessories for the AMC1311 and C87AT output waveform in the respective exit point voltage of which is 5V voltage, blue, green as the output voltage of AMC1311 and C87AT, sampling for the power supply voltage of 24V, yellow is a 393 output voltage comparator, when AMC1311 (C87AT) reference voltage output voltage is higher than a 1.5V, 393 output high level, lower than 1.5V, 393 output low level, from the two picture it can be seen that when the 5V voltage is lower than 4.5V (picture in Y axis intersection position and blue dotted line), AMC1311 and C87AT do not work, but the output voltage of the C87AT directly dropped, and the output of AMC1311 The voltage was upwards (higher than the reference 1.5V) and then dropped, causing my 393 comparator to misoperate. What is the cause of the burr?
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AMC1301-Q1: VDD1 supplied with 3.3V against recommend 5V
Part Number:AMC1301-Q1
Hi All,
Datasheet recommends 5V for VDD1 though the range is from 3 to 5.5V
I would like to know whether VDD1 and 2 can be given 3.3V from the same source or not. Appreciate your assistance.
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AMC1311: For AC Voltage Sensing
Part Number:AMC1311
Customer is intrested in the AMC1311 for the AC mains sensing. Customer found the input environment noise would affect the output performance.
1. Could you help to check if below circuitry is ok or need to be improved?
2. Is there AMC13xx ref. design with AC voltage sensing?
3. Is there other suggestion for AC mains sensing with AMC device?
Application: PV Inverter
Watts: 50KW
Input voltage: 277Vac to 370Vac
Schematic:
ch1: S-N
ch2: Vout_S
ch3: +5V
ch4: Io_S Current
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TLV521: Looking for current sense amplifier 1 uA to 10 mA.
Part Number:TLV521
Dear team,
My customer is looking to add a current measurement capability in their devices
The solution should consume about one micro ampere.
It could be current sense amplifier (discrete built or solid) and a comparator with hysteresis (I need digital output).
Measured currents 1 uA to 10 mA.
Appreciate your suggestions.
Thanks in advance and regards,
Shai
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LMP7721: Dual supply operation
Part Number:LMP7721
Are there known issues operating this chip with +/- 2.5V supplies instead of a single rail 5V supply? I assumed it would work with dual rails provided the total differential voltage was within limits, but now I'm not so certain.
My supplies come from a LM27762, and I am seeing a lot of noise on the output of the LMP7721 that has been amplified from the supply rails. The PSRR spec of 92dB is specified for a single rail supply, and it has made me question if attempting to use dual rails is the source of the trouble. I'm using the LMP7721 as a current integrating preamp in the following configuration, so the gain is fairly substantial:
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