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OPA140: Vos Long-Term Stability
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LMH6518: Request for input noise spectral density and output noise spectral density for each gain
Part Number:LMH6518
Hi team
Could you share with us about input noise spectral density and output noise spectral density for each gain?
Best Regards,
Takanori Yuzawa
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LMP2011: unstable of output
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INA103: INA103 Instrumentation Amplifier for AC Applications
Part Number:INA103
Hello, I am looking for advice for choosing the best amplifier that is to be connected to a Wheatstone Bridge that is supplied with an AC source. I am currently using an INA110 instrumentation amplifier connected to the bridge but it is currently supplied with a DC source. I was wondering if it is possible for this set-up to run the bridge with an AC source? and also, which amplifier would be better, as we are trying to obtain a gain of 10 and run a frequency of 100-300kHz through the amp. Any suggestions are welcomed, thank you!
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AMC1200: How to verify the surge capability
Part Number:AMC1200
Hi Team,
My customer is surveying AMC1200 and the component engineer has a question. In the datasheet, it shows the capability of part's surge immunity(IEC61000-4-5) can be up to +-6KV and he has to verify it's performance. He has no idea how to verify it on device but not on system and think TI should has document to test this device's performance. So, do team have such materials can be shared to my customer?
Thanks a lot.
Vincent Chen
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OPA2197: Gain vs frequency question
Part Number:OPA2197
I have used 2 opa2197(one chip) in differential amplifier configuration. One's output is connected to the other's input. My closed loop gain is(should be) ~3 for both of them. I have a signal of +-0.34V sinusoidal at the input of the first amplifier. Amplifiers' supply is +-9V. I want the input signal to be 400KHz. At low frequencies like below 50KHz everything seems to be normal. But as frequency goes up to ~280KHz the output gets larger (i.e. gain is increasing); after that frequency the output is getting smaller (i.e. gain is decreasing). What is the reason of this? What can I do?
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XTR111EVM: what's the function about R8 and R10
Part Number:XTR111EVM
Team,
i'd like to know what's the function about R8 and R10.
1. when we add a 5V input voltage, Vin test point is 0.5V. why it happen ?
2. could we reduce R8 and R10 ?
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TINA/Spice/INA332: Differrent Output of INA332 insrtumentation amplifier
Part Number:INA332
Tool/software:TINA-TI or Spice Models
I was trying to use INA332 in my design where I want gain around 160, but I was not getting it. I have used components as given in the datasheet of INA332.
Input voltages are 1.5V and 1.51V. and gain resistors are 68.1K and 2.2k. So, output voltage should be 1.59V, but it is giving 2.93V.
schematic is here: (Please visit the site to view this file)
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OPA4379: OPA4379 Damage problem
Part Number:OPA4379
Dear TI：
In BLE thermometer project using OPA4379 has damage phenomenon. By the screenshots shown below:
The OPA power supply voltage(AVCC) is controlled by CC2541 P1_0 . When AVCC is low and battery is full, OPA input always connect on the resistive divider network .
Please help analyze , the input voltage is higher than the supply voltage might damage the OPA ? Or is there any other possibility of damage ? Many thanks~
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OPA340: offset voltage for R/C integral
Part Number:OPA340
Hello
I have a question regarding the offset voltage caused by the R/C integral.
I would like the measure a signal from the output from Rogowski Coil. I use a R/C integral after. R is 1000k ohm and C is 5.6nF. And I use a Non-invert input Op Amp circuit to amplify the signal. I use 1.5V as the middle voltage. But I found the offset in the output of the R/C is 1.51V. Additional 80mV appears. When I reduce the resistor value. The offset reduced. Who can tell me how the offset occurs and how to reduce it?
Thanks!(Please visit the site to view this file)
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OPA2343: Using a single supply op amp with a dual supply.
Part Number:OPA2343
Is it possible to use the OPA2343 op amp with a dual supply and if it is possible will I encounter any undesireable behaviour or deviation from the specifications on the datasheet? For example, I want to supply the op amp with ±2.5V, the positive input terminal with ±0.5V and the negative input terminal with between -1.5V and -2.5V. I realise that I could use a dual supply op amp, but I would like to know what would happen if I used a single supply op amp such as the OPA2343.
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LM2917-N: LM2907/LM2917 variable reluctance sensor buffer to TTL
Part Number:LM2917-N
Hello.
We have a variable reluctance sensor that we would like to buffer to a TTL or other voltage level. The LM2907/2917 seems like a good candidate. On page 20 of the datasheet, figure 28 a circuit is described that outputs pulses at twice the frequency of the input frequency.
I assume the unit of the duty cycle is time and as our Vcc is 24V the duty cycle will equal C1 according to the formula. We will sample the pulse train with a minimum frequency of 9 MHZ and a maximum of 30 MHz.
Assuming we sample the pulse train with 9 MHz we have to have a pulse width that is wide enough that the sampling device will detect it.
For example lets say the waveform has a frequency of 4.5 MHz and the duty cycle is 50%. I want my two-shot output duty cycle to be of the same time duration. Assuming Vcc = 24 that leaves me with a C1 of 11 uF. Is there any danger in using this large a capacitor?
In the example the capacitor is 500 pF which is way less and I reckon this would be used with an MCU to calculate the frequency using some interrupt service routine triggered by the pulses. We want to sample the waveform and do calculations afterwards.
The DAQ used is the NI 9401. The reason we want to use this and sample the waveform is to integrate it with other NI modules with which we sample other signal types.
Any suggestions/ideas?
Best regards,
David Kantzon
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OPA725: Question about OPA725 spec in datasheet
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TINA/Spice/OPA4180: Spice Model problem
Part Number:OPA4180
Tool/software:TINA-TI or Spice Models
Hi, I'm trying to test the OPA4180 Psipce Model on Orcad. This is the simple circuit I have implemented:
But when I run the simulations I get always this convergence error. This is the simulation output file:
**** CIRCUIT DESCRIPTION
******************************************************************************
** Creating circuit file "TRAN.cir"
** WARNING: THIS AUTOMATICALLY GENERATED FILE MAY BE OVERWRITTEN BY SUBSEQUENT SIMULATIONS
*Libraries:
* Profile Libraries :
* Local Libraries :
.LIB "../../../sbom804.lib"
* From [PSPICE NETLIST] section of C:\Cadence\SPB_16.5\tools\PSpice\PSpice.ini file:
.lib "C:\Documents and Settings\Administrator\Desktop\library\nom.lib"
*Analysis directives:
.TRAN 0 400u 0 0.1u
.PROBE V(alias(*)) I(alias(*)) W(alias(*)) D(alias(*)) NOISE(alias(*))
.INC "..\SCHEMATIC1.net"
**** INCLUDING SCHEMATIC1.net ****
* source OPTOISOLATOR
R_RL 0 VOUT 100k
C_C1 0 VOUT 10p
R_R1 N14347122 VOUT 10k TC=0,0
R_R2 N14348773 N14347122 10k TC=0,0
V_V2 0 N14349980 18Vdc
V_V3 N14348370 0 18Vdc
X_U1 N14347122 0 N14349980 N14348370 VOUT OPA4180
V_V4 N14348773 0
+PULSE 15 -15 0 1n 1n 100u 200u
**** RESUMING TRAN.cir ****
.END
**** 04/30/17 11:31:10 ****** PSpice 16.5.0 (April 2011) ****** ID# 0 ********
** Profile: "SCHEMATIC1-TRAN" [ c:\atib\optoisolator\optoisolator-pspicefiles\schematic1\tran.sim ]
**** Diode MODEL PARAMETERS
******************************************************************************
X_U1.XIn11.DVNF X_U1.XVn11.DVN X_U1.XU13.DNOM X_U1.XU8.DNOM
IS 100.000000E-18 100.000000E-18 1.000000E-15 1.000000E-15
RS 1.000000E-03 1.000000E-03
TT 10.000000E-12 10.000000E-12
CJO 1.000000E-18 1.000000E-18
KF 3.162278E-12 31.622780E-12
X_U1.XU12.DNOM X_U1.XU2.DNOM X_U1.XU11.DNOM X_U1.XU10.DNOM
IS 1.000000E-15 1.000000E-15 1.000000E-15 1.000000E-15
RS 1.000000E-03 1.000000E-03 1.000000E-03 1.000000E-03
TT 10.000000E-12 10.000000E-12 10.000000E-12 10.000000E-12
CJO 1.000000E-18 1.000000E-18 1.000000E-18 1.000000E-18
**** 04/30/17 11:31:10 ****** PSpice 16.5.0 (April 2011) ****** ID# 0 ********
** Profile: "SCHEMATIC1-TRAN" [ c:\atib\optoisolator\optoisolator-pspicefiles\schematic1\tran.sim ]
**** Voltage Controlled Switch MODEL PARAMETERS
******************************************************************************
X_U1.S_VSWITCH_1
RON 10
ROFF 100.000000E+06
VON .1
VOFF -.1
X_U1.S_VSWITCH_2
RON 10
ROFF 100.000000E+06
VON .1
VOFF -.1
X_U1.S_VSWITCH_3
RON 1
ROFF 10.000000E+06
VON .1
VOFF -.1
X_U1.S_VSWITCH_4
RON 1
ROFF 10.000000E+06
VON .1
VOFF -.1
X_U1.S_VSWITCH_5
RON 1
ROFF 100.000000E+06
VON 150
VOFF 0
X_U1.S_VSWITCH_6
RON 1
ROFF 100.000000E+06
VON 150
VOFF 0
X_U1.S_VSWITCH_7
RON 1.000000E-03
ROFF 10.000000E+06
VON -.01
VOFF 0
X_U1.S_VSWITCH_8
RON 1.000000E-03
ROFF 10.000000E+06
VON .01
VOFF 0
X_U1.S_VSWITCH_9
RON 1
ROFF 10.000000E+06
VON 1
VOFF -1
X_U1.S_VSWITCH_10
RON 1
ROFF 10.000000E+06
VON 1
VOFF -1
X_U1.S_VSWITCH_11
RON 1
ROFF 1.000000E+09
VON 10
VOFF -10
X_U1.S_VSWITCH_12
RON 1
ROFF 1.000000E+09
VON 10
VOFF -10
X_U1.S_VSWITCH_13
RON 1
ROFF 10.000000E+06
VON 10
VOFF -10
X_U1.S_VSWITCH_14
RON 1
ROFF 10.000000E+06
VON 10
VOFF -10
ERROR -- Convergence problem in transient bias point calculation
Last node voltages tried were:
NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE NODE VOLTAGE
( VOUT) 0.0000 (X_U1.13) 0.0000 (X_U1.14) 0.0000
(X_U1.15) 0.0000 (X_U1.16) 0.0000
(X_U1.17) 0.0000 (X_U1.18) 0.0000
(X_U1.19) 0.0000 (X_U1.20) 0.0000
(X_U1.21) 0.0000 (X_U1.22) 0.0000
(X_U1.23) 0.0000 (X_U1.24) 0.0000
(X_U1.25) 0.0000 (X_U1.26) 0.0000
(X_U1.27) 0.0000 (X_U1.28) 0.0000
(X_U1.29) 0.0000 (X_U1.30) 0.0000
(X_U1.31) 0.0000 (X_U1.32) 0.0000
(X_U1.33) 0.0000 (X_U1.34) 0.0000
(X_U1.35) 0.0000 (X_U1.36) 0.0000
(X_U1.37) 0.0000 (X_U1.38) 0.0000
(X_U1.39) 0.0000 (X_U1.40) 0.0000
(X_U1.41) 0.0000 (X_U1.42) 0.0000
(X_U1.43) 0.0000 (X_U1.44) 0.0000
(X_U1.45) 0.0000 (X_U1.46) 0.0000
(X_U1.47) 0.0000 (X_U1.48) 0.0000
(X_U1.49) 0.0000 (X_U1.50) 0.0000
(X_U1.51) 0.0000 (X_U1.52) 0.0000
(X_U1.53) 0.0000 (X_U1.54) 0.0000
(X_U1.55) 0.0000 (X_U1.56) 0.0000
(X_U1.57) 0.0000 (X_U1.58) 0.0000
(X_U1.59) 0.0000 (X_U1.60) 0.0000
(X_U1.61) 0.0000 (X_U1.62) 0.0000
(X_U1.63) 0.0000 (X_U1.64) 0.0000
(X_U1.65) 0.0000 (X_U1.66) 0.0000
(X_U1.67) 0.0000 (X_U1.68) 0.0000
(X_U1.69) 0.0000 (X_U1.70) 0.0000
(X_U1.71) 0.0000 (X_U1.72) 0.0000
(X_U1.73) 0.0000 (X_U1.74) 0.0000
(X_U1.75) 0.0000 (X_U1.76) 0.0000
(X_U1.77) 0.0000 (X_U1.78) 0.0000
(X_U1.79) 0.0000 (X_U1.80) 0.0000
(X_U1.81) 0.0000 (X_U1.82) 0.0000
(X_U1.83) 0.0000 (X_U1.84) 0.0000
(X_U1.85) 0.0000 (N14347122) 0.0000
(N14348370) 0.0000 (N14348773) 0.0000
(N14349980) 0.0000 (X_U1.XIn11.3) 0.0000
(X_U1.XIn11.4) 0.0000 (X_U1.XIn11.5) 0.0000
(X_U1.XIn11.6) 0.0000 (X_U1.XIn11.7) 0.0000
(X_U1.XIn11.8) 0.0000 (X_U1.XR103.3) 0.0000
(X_U1.XR104.3) 0.0000 (X_U1.XR105.3) 0.0000
(X_U1.XR106.3) 0.0000 (X_U1.XR107.3) 0.0000
(X_U1.XR108.3) 0.0000 (X_U1.XR109.3) 0.0000
(X_U1.XU15.40) 0.0000 (X_U1.XVn11.3) 0.0000
(X_U1.XVn11.4) 0.0000 (X_U1.XVn11.5) 0.0000
(X_U1.XVn11.6) 0.0000 (X_U1.XVn11.7) 0.0000
(X_U1.XVn11.8) 0.0000 (X_U1.XR103.30) 0.0000
(X_U1.XR104.30) 0.0000 (X_U1.XR105.30) 0.0000
(X_U1.XR106.30) 0.0000 (X_U1.XR107.30) 0.0000
(X_U1.XR108.30) 0.0000 (X_U1.XR109.30) 0.0000
(X_U1.XR109_2.3) 0.0000 (X_U1.XR109_2.30) 0.0000
**** Interrupt ****
I tried the same model circuit in TINA and it works. Any suggestions on how I can fix this?
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Need Unity Gain Op Amp To Drive 100 ohm, 2200pF Load
I need a unity gain stable op amp that can drive high capacitance loads. Before I provide the requirements of the unity gain buffer let me describe the overall circuit:
The entire circuit looks like this: An INA139 is being used as a high side sense in a buck charger - sensing 25mV across a 100 mOhm current sense resistor and providing 50mV at its output across a 2k resistor This 100-200KHz inductive ramp waveform is then buffered before it feeds the SNS pin of a buck charger with a 50mV pk-pk ramp. Note: the 50mV pk-pk inductive ramp voltage is representative of 250mA across the 100 mOhm high side current sense resistor.
The unity gain buffer needs to accept a 50mV, 100-200KHz ramp or sawtooth waveform on its input and provide a 50mV pk-pk ramp output driving a 100 ohm in parallel with 2200pF.
I'm looking for some suggestions for the unity gain buffer which clearly needs to be unity gain stable, with low input offset voltage (less than 1mV), preferably low input bias current with the ability to drive low resistance, high capacitance loads.at the frequencies specified - again we're talking about 100 ohm load in parallel with 2200pF.
I can provide additional info and welcome a call.
Please let me know what you can recommend.
Thanks & regards,
John Garrett, TI-AFA
Cell: 240 687-0350
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XTR111EVM: 4-20mA accuracy issue at high ambient temperature ( > +65C)
Part Number:XTR111EVM
Hello Sir,
Attached SCH shows our 4-20mA conversion circuit which is part of the circuit in our design. Basically we used design of TI evaluation board for XTR111.
The 4-20mA accuracy of this circuit meets our requirement when ambient temperature is between -40C to +60C.
However, when temperature rises over +65C, the 4-20mA output current was out of our specification (< 2.5%) if Vin was below 2V.
The accuracy comparison can be found in the other attached file.
We measured the voltage of R226 (shown in attached SCH), this voltage only changed a little (less than 0.5%) compared with the voltage value at +22C.
It looks like that the current passing through B pole and E pole of Q8 significantly increased at +85C so that the 4-20mA output current accuracy was severely degraded.
Because we used TI's evaluation design, does any one of TI engineers know this issue? Is there any recommendation to get it improved?
Thanks
William Chen
(Please visit the site to view this file)
(Please visit the site to view this file)
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PGA309: Noise/Ripple Problem
Part Number:PGA309
Hi,
I'm testing the PGA309 EVB with a high precision tester and I've found that the Output voltage is not very stable: it doesn't drift but last digit oscillates with an amplitude of 3mV (when signal is 3V). I'm using internal Vref - 4.096V.
Do you have any advice?
Best Regards,
Mattia
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TINA/Spice/OPA333: Offset voltage of integrator
Part Number:OPA333
Tool/software:TINA-TI or Spice Models
Hi team,
I have a question about offset voltage of integrator.
My customer uses integrator (shown in attached file) as a part of delta-sigma modulator(10ksps).
OPA333 is adopted to consist integrator, its input offset voltage is 10uV in maximum.
However, mV order offset came out at output of integrator.
If someone have an idea to reduce offset voltage of integrator, please share it.(Please visit the site to view this file)
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Finding a current sensing amplifier for my design conditions
Hello,
I am aman and I am working on a sensor circuit design to measure the ethylene concentrations. My sensor circuit presents an output range of 0.04uA to 4uA. But I need to add a current sensing amplifier to measure the current at any particular moment which can also amplify the signal or output a voltage which can be then interpreted by the ADC.
I have been trying to find it but it is complex and difficult. Could you please help me out in finding the most suitable amplifier for my requirements.
thanks
aman
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OPA2350: Input damage when powered down
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