Part Number:OPA2209
Hi All,
for the opamp OPA2209AIDR can you please let me know at what forward voltage does the back to back diodes on the opamp input terminals start conducting 10mA of current?
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OPA2209: OPA2209 back to back diodes on input terminals
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TINA/Spice/OPA189: TINA-TI MACRO BUG?
Part Number:OPA189
Tool/software:TINA-TI or Spice Models
Hi There.
Can someone help me about the followings:
I have a TINA-TI simulations with OPA827 and i want to change it to OPA189.
Can i change it?
I want to use it for only DC signal i dont need to measure any highspeed signal or fast changes.
if i change it the simulations show very unaccaptable data.
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LMC6482: Operating at dual supply+/-3V
Part Number:LMC6482
I operating the LMC6482 in dual supply (+/-3/3VDC) and I'm trying to understand if the device is capable of operating properly under those conditions.
The spec sheet is unclear how low the dual supply can be. Max Voltage is stated at 16V (Vcc - Vee) but it makes no mention of lowest. The only other value are single supply at +5V (Vcc) and 0V (Vee)
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LF298: Does S&H Droop When No Load on Output?
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LM331: LM331 Voltage to Frequency conversion problems
Part Number:LM331
I am trying to debug 50 boards that are implementing the LM331 as a voltage to frequency converter. My desired frequency is 3.9 kHz. On 10 of the boards the frequency is within +/- 2kHz which is okay for my application. However on the rest of the boards the frequency is more like from 7.2 kHz to 8.4kHz. And i havent founf any difference regarding to the voltages on the pins.. The voltages at all the other pins are the same. All my resistors are 1% and the caps are 5%. I've tried changing Rt, Ct and the LM331 but the result is still the same. My schematic is shown with a 3.6V input. Any suggestions as to why this is? Disregard the notes on the schematic. Also any other solution other than that of putting POT. Thank You
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LM2907-N: Using Equation 6 of Data Sheet to Calculate Ripple
Part Number:LM2907-N
Hi there, I want to use equation 6 of the data sheet to verify the amount of voltage ripple in order to properly select C1, C2 and R1 for the LM907-N. The data sheet does not specify what pk is and I cannot calculate this without knowing it. I have attached a copy of the equation for reference:
Can you please tell me what pk stands for?
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LMH6321: about LMH6321 power supply
Part Number:LMH6321
hi dear supporting team,
customer is using TPS7A801 to supply 5V for LMH6321, with 10uF,0.1u,1nF bypass cap close to the pin, and also a ferrit bead of 150Ohm in seriers. there are around 50% brds have 28kHz glitchs at the output of LMH6321, if change the power supply of LMH6321 to external DC-DC, then there is no such issue. from some experiment we think it is some reasonance btw the power supply pin of LMH6321 and TPS7A801, we triied more bypass cap btw them, while no improvement. and the TPS7A801 also be power supply for some other amp, it seems has no such issue. the load of LMH6321 is a switch, so for LMH6321 power supply , if the loading is heavy, is there any more effort we could take? tks a lot!
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TLV8812: the input signal and power supply is not stable because of switching input channel
Part Number:TLV8812
Dears
I want to use TLV8812 to replace OPA2333, use the the same Sch,But the result is different. The application is to acquire two TS resistor, we use MOSFET to switch channel,the sch as follow
At the beginning of power up, the output of TLV8812 is same as OPA2333, after about 4-8hours, the output become unstable, the power supply COL_ADC has some noise,and when we switch channel by MOSFET, the input of TLV8812 become unstable too. We also test tlv2333, the phenomenon came up again, Would you pls give us some advice to check the circuit? Thanks a lot.
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TINA/Spice/OPA211: OPA211
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OPA4277: opa4277
Part Number:OPA4277
I have only one CT, and I want to deliver the signal to 4 DSP at the same time.
Can I use OP amp to do that? How to assure 4 DSP get the same and correct information?
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INA129: Circuit verification
Part Number:INA129
One of the circuits I’m working on has a current input signal derived from an external sensor device with a signal range of 0 to 66.6mA full scale.
I need to turn this into a 4-20mA signal, for which, I’m using an INA129 as a trans-impedance amp with an input shunt resistor to derive a full-scale input voltage of 5V to the amp, which is passed through an LPF per the sketch below:
I’ve used this LPF circuit before with INA121’s and would like confirmation that there is no issue with using the same LPF configuration with 129’s.
The gain of the 129 is set at 2 giving a 0V to 10V output swing.
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TINA/Spice/OPA333: Operating point not found for my circuit
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LMP7721: Evaluation board: single supply + bias voltage issue
Part Number:LMP7721
Hi TI engineers!
(I expect to be answered by Paul Grohe, as he was responsible for the design of the above mentioned circuit board, however, it isn't necessary to)
I'm evaluating the LMP7721 eval. board to see if it fits for my application, which is just read a pH probe sensor. For this application I need a very high input impedance and level-shift the signal, as the pH probe works in a range of approx. +-500mV and I will use single supply (+5V and 0V). Also, I don't use TRIAX conector, just a normal BNC, i.e., guard is necessary but not connected to the BNC plug.
Here comes my question: Regarding the document "LMP7721 Multi-Function Evaluation Board Users' Guide", page 5, section 4.1.1, Figure 2 shows the "Non-Inverting Configuration (Factory Configuration)", which seems to be the best for my job. However, if we modify this circuit for single power supply instead of dual, and therefore, change the guard level from GND to Vbias by connecting pads 1 and 2 instead of 2 and 3 of RFb in Figure 9, pg 13, the Vbias voltage will appear in the output just as: Vout = -RFa/RFb x Vbias, i.e., the offset voltage appears inverted (negative) in the output! But it doesn't make sense as I will use a single power supply. Am I doing something wrong?
Is this board suppose to work with single supply and Vbias applied to the guard?
Regarding the second configuration shown in section 4.1.2 "Inverting configuration", page 6, this configuration seems to fix the above mentioned problem, however, the input impedance for this configuration (Figure 3) is about Rs+R2, i.e., about 1MOhm (Am I correct?). So, it's not such high impedance.. how can it work for a pH probe, for example, that as output impedance range of about 10MOhm to 1GOhm?
Looking forward to get a reply!
Thanks :)
Best Regards,
Luciano Caldas
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OPA703: Logo marking
Part Number:OPA703
Hi,
I would like to confirm about logo on OPA703UA.
My customer got OPA703UA devices, but the logo on the devices is not TI, but Burr-Brown.
Could you please confirm if Burr-Brown logo is still used on this part and if TI logo is not used ?
Thank you in advance.
Best Regards,
Raku
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OPA2189: RTM
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TINA/Spice/OPA333: Unable to simulate AC analysis
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LOG114: LOG114
Part Number:LOG114
Hi,
We are using LOG114 for measuring current ranging from 100pA to 8mA.
Our Iref is 1 uA. It is generated from a stable voltage reference diode and series resistance.
Output Vlog out is perfect when input is from 1uA to 8mA. When input is below 1uA out put is not
as expected. We tried the solutions like cleaning PCBs with IP, covering LOG114 in the aluminium shield. Using Battery
as power supply. Power supply we are using to LOG114 is 0 to 5V.
We matched out PCB layout as per LOG114EVM.
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TINA/Spice/opa333: operating point not found while simulating ac transfer characteristics
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INA103: INA101: INA101 dying after a few days
Part Number:INA103
Hello, We've been using the INA103 for 25 years as current sense amplifiers in circuits similar to yours. Assuming you have the reference pin (7) tied to the common ground of your floating power supply and INA103 supply then a suggestion is to provide transient protection on the inputs. The Ap Notes suggest a 50 ohm resistor paralleled with a 1.2uH inductor in series with each input. We place PNP SOT23 transistors (lower leakage) to the supply rails. These are configured differently - collector to the input, base to +15V and base to the input, collector to -15V.
Turn on/turn off and load transients can result in brief but damaging over voltage events on the inputs of the INA103. This should eliminate one possible source of your problem.
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LMP91000: P11 VFEF could connected to positive and negative voltage?
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