Tool/software:TINA-TI or Spice Models
I have designed the multistage amplifier with OPA37GP and dual amplifier band pass filter using OPA2111KP. Kindly suggest me, what kind of PCB (single layer or double layer) would be suitable for this type of preamplifer.
Part Number:TLV171
Tool/software:TINA-TI or Spice Models
Hi,
I have downloaded the TINA file for TIDA-01371 reference design from here:
Simulation results are the same as described in tiduci3a.pdf . However, when I change the TLV171 supply voltage (VCC) from 12V downto 5V, then simulation results are very strange to me. What should I change in the reference design in order to be able to operate the circuit with 5V supply? For some reasons this would be much more convenient for me.
Best Regards,
Mariusz Hajduk
Part Number:INA240
Does TI make a simple single stage isolation amplifier with similar TSSOP8 pin orientation? The PCB layout for primary current monitors has pads for a 240 partner REF control by output of primary 240. We like to add additional TSSOP8 amplifier to isolate primary 240 output prior to entering ADC without the complex Delta Sigma scheme. The 240 SNR into ADC is a bit high even with series R and distortion of current measure error occurs >400us sample settling.
Can 2nd buffer add some ADC isolation and REF1/2 inputs are tied to output of 1st 240? Also circuit can ground +/-IN pins of 2nd 240 makes it inverting isolation stage or buffer for the 1st 240?
Another question TI "Selecting amplifiers for shunt based current sensing" PDF (Figure.2-2) states low side shunt produces an inverted signal to +/-IN, e.g Table 1 low side monitor (Challenges column).
When 240 REF1/2 are wired +1.225v that seemed to occurre and I was challenged in this forum it was impossible. The bad part was the 240 output raised shunt inversion above REF1/2 +1.225v threshold. A scope capture seemed to indicate the shunt signal on 240 output was indeed inverted and became obvious via added 22nF decouple filter cap into ADC. Can TI confirm Fig2-2 is accurate low side shunt signal is inverted, when +IN non-inverting input faces B+ on low side monitor? It seems when REF1/2 wired to GND the 240 output inversion is seemingly not occurring as bad. Yet it seems the +IN should be measuring forward current into ground and instead is measuring inverter reverse current, e.g. Fig2-2 example above (>0v) ground. Shunt inversion seems to explain why scope tends to capture PWM transients outside 240 sample point. Oddly the sample point (Fig.2-2) is occurring >400us after the timed event and should be occurring no later than 9.6us @0.5% of final value.
Part Number:THS4531
HI,
I have a question using THS4531 as a signal conditioning circuit for TMS320F28377D.
Currently, I am using a differential signaling mode (16 bit) ADC with 3 V VREFHI, and 1.5V VOCM. The circuit diagram follows the figure below (from tidu569)
I am wondering if I can use the circuit for a single-ended signaling mode (12 bit) adc only with single output (AINP1P) as shown in the figure below.
Best Regards,
Jongwan
Part Number:OPA196
Hello; I've been tasked with designing a low-cost AFE to measure a 4 cell battery and need to clarify a couple issues with your OPA19x family. The design uses a 4 channel mux (DG4052E), and I had initially selected the OPA196 for ist low $. However, I had forgotten about the issues with the op-amp's inputs being vulnerable to large swings while the mux is transitioning. The 196 is not listed in SBOT040A as a "Mux-Friendly" amp, and so I've replaced it with the OPA191. Can you confirm that the 196 is NOT "mux-friendly". And can you suggest any alternatives, low cost and >16Vs max are parameters.
Thanks
Part Number:THS4551
Hi Team,
My customer is evaluating THS4551's linearity performance but we found some issues and need team's comment.
1. Below is customer's circuit, this gain is 1k/6.05k and is that correct?
2. Please find below measurement result, the gain error is quite large when Vin voltage is small, say about lower than 1V. Is the result reasonable? How to improve the linearity? (Asked customer to use multimeter to measure the real Vin voltage, when DC supply is 10mV, the measured Vin voltage is 10.185mV. A small error won't cause large gain error)
(Please visit the site to view this file)
3. Since it is not tested on TI's EVM but connected by long wire, is it possible to cause the error?
Thanks a lot.
VIncent Chen
Part Number:OPA548
OPA548: We have a situation where we are following a circuit very similar to your Evaluation board SBOU132 (Figure 1) including the "Motor " Diodes (D1/D2) where we have a solid DC voltage going into the inputs of U1. the output has a 1:1.5 transformer across R6/C8 which is probably sinking any output. The reason we have DC is our VDD and VSS PS are left on during test and put about approximately 6.5 VDC on U1-1 and U1-2. When this occurs we get about 70 DegF rise on the op-amp a jump up from 70 nominal. We are well within the thermal parameters of the op-amp is there any concern about long term stays in this condition?
Part Number:AMC1300
Hi Guys
I'm trying to use the AMC1300B to measure a 1mR shunt resistor. For the most part it's working well (good accuracy) but I am getting more noise than I expected on the output OUTP OUTN. For my tests I have isolated the circuit down to the shunt resistor (0A) and OUTP-OUTN terminated into 3k3 at the legs. I am supplying both rails at 5V with separate bench supplies.
Common mode (OUTP or OUTN to GND2) they exhibit a 20mVpp oscillation at about 600kHz (should I suppose this is the SD modulation frequency?) and in the real circuit this is rejected by the differential amplifier:
I also have up to 10mVpp of differential noise which gets as low as about 300kHz - this is getting into the original circuit's opamp output. The waveform below is measuring the differential output using the scope subtraction. Is this the expected behaviour of this IC or have I done something wrong? It's certainly well above any noise specs in the datasheet but they stop at 100kHz/200kHz. Should I be applying more low pass filter?
Thanks
Stewart
Part Number:OPA727
Dear Sir/Madam,
Can I know the meaning of the OPA727AIDGKR IC marking for 8772 and 63x7?
Best Regards,
kpk
Part Number:INA233
I m developing an application where i need to read ina233 bus voltage , current etc with an isolator ISO1541 in between MCU and INA233. So i2c communication happens between mcu----1SO1541----INA233.
For testing purpose i am trying to read the MFID (Manufacturer id from reg address 0x88) . But I am not able to read the complete 2 byte data, I just receive the (2,255) from the IC.i.e second byte read is always high.
Sharing the code with functions :
data = read_ina(0x88); // for reading the data from the reg address 0x88.
unsigned char read_ina(unsigned char address)
{
unsigned int temp=0,temp2=0;
unsigned char add_lo = 0,add_hi = 0;
unsigned char reg_address = 0;
reg_address = address;
start1(); delay_us(300);
write_byte_ina233(0x88); //delay_us(300); //slave address + write bit
write_byte_address_ina233(reg_address); //delay_us(300); // register address
stop1(); delay_us(300);
start1(); delay_us(300);
write_byte_ina233(0x89); trisb.f3 = 1;delay_us(300); //slave address + read bit
ina_data_lsb = read_byte_ina233_ack(); //delay_us(300);
ina_data_msb = read_byte_ina233_nack(); //delay_us(300);
stop1(); delay_us(300);
return(ina_data_msb);
}
Other functions are as follows :
void start1(void)
{
trisb.f3 = 0;delay_us(300);
sda_iso1541 = 1 ; delay_us(300);
scl_iso1541 = 1; delay_us(300);
sda_iso1541 = 0 ; delay_us(300);
scl_iso1541 = 0; delay_us(300);
}
void stop1(void)
{
trisb.f3 = 0;delay_us(300);
sda_iso1541 = 0 ; delay_us(300);
scl_iso1541 = 1; delay_us(300);
sda_iso1541 = 1 ; delay_us(300);
}
void write_byte_ina233(unsigned char val)
{
unsigned char x=0;
trisb.f3 = 0;delay_us(500);
for(x=0;x<=7;x++)
{
if(val & 0x80)
{sda_iso1541 =1;}
else
{sda_iso1541 =0;}
delay_us(500);
scl_iso1541 =1;
delay_us(500);
scl_iso1541 =0;
delay_us(500);
val = val << 1;
}
trisb.f3 = 1;delay_us(500);
scl_iso1541 =1;
delay_us(500);
scl_iso1541 =0;
delay_us(500);
//trisb.f3 = 1;delay_us(300);
}
void write_byte_address_ina233(unsigned char val)
{
unsigned char x=0;
trisb.f3 = 0;delay_us(500);
for(x=0;x<=7;x++)
{
if(val & 0x80)
{sda_iso1541 =1;}
else
{sda_iso1541 =0;}
delay_us(500);
scl_iso1541 =1;
delay_us(500);
scl_iso1541 =0;
delay_us(500);
val = val << 1;
}
trisb.f3 = 1;delay_us(500);
scl_iso1541 =1;
delay_us(500);
scl_iso1541 =0;
delay_us(500);
//trisb.f3 = 1;delay_us(300);
}
unsigned char read_byte_ina233_ack(void)
{
unsigned char x=0,val=0;
//trisb.f3 = 1;
delay_us(300);
for(x=0;x<=7;x++)
{
val = val << 1 ;
delay_us(500);
val = val | sda_iso1541;
delay_us(500);
scl_iso1541 =1;
delay_us(500);
scl_iso1541 =0;
delay_us(500);
}
delay_us(500);
scl_iso1541 =1;
delay_us(500);
scl_iso1541 =0;
delay_us(500);
return(val);
}
unsigned char read_byte_ina233_nack(void)
{
unsigned char x=0,val=0;
//trisb.f3 = 1;
//delay_us(300);
for(x=0;x<=7;x++)
{
val = val << 1 ;
delay_us(500);
val = val | sda_iso1541;
delay_us(500);
scl_iso1541 = 1;
delay_us(500);
scl_iso1541 = 0;
delay_us(500);
}
//trisb.f3 =0;delay_us(100);
return(val);
}
Kindly let me know for some issue with the code .
Or please send me sample code for reading some register value.
Part Number:LMH6643
Hello;
I am trying to choose an opamp, which input 10 mHz is 0-2 volt sinusodial signal.
FPBW = SR/(2*pi*V)
So A opamp must be chosen which slew rate is 125V/us.
Am I right?
Can you explain -3dB bandwidth, full power bandwidth, slew rate and relation between them.
Best Regards.
Hi Sirs,
Sorry to bother you.
Does TI have Current monitor can support Windows E3 (Energy Estimation Engine)
Such like PAC1932?
http://ww1.microchip.com/downloads/en/DeviceDoc/PAC1932-Data-Sheet-DS20005850C.pdf
Part Number:TS321-Q1
Hi team,
My customer is using TS321-Q1 in buffer circuit for DC input voltage sensing. However, during every switching rising and falling edge of main DC/DC converter, TS321 output will have glitch and overshoot. Please see waveform and schematic below:
CH1 TS321 VCC (Pin 5)
CH2 Buffer_OUT (Pin 1)
CH3 Buffer_IN (Pin 3)
CH4 Main DC/DC Converter Switching Node
And we changed the op-amp from TS321 to OPA192 (keeping all surrounding components the same), this problem is gone. Could you suggest what are the op-amp spec differences may lead to this improvement?
CH1 TS321 VCC (Pin 5)
CH2 Buffer_OUT (Pin 1)
CH3 Buffer_IN (Pin 3)
CH4 Main DC/DC Converter Switching Node
Many thanks.
Best Regards,
Wei-Hao
Part Number:OPA2111
Tool/software:TINA-TI or Spice Models
Hello,
With reference to my previous thread https://e2e.ti.com/support/amplifiers/f/14/t/778421, I have one more doubt on my design. This design is giving a fixed output voltage i.e. 7.5 volts which are given at the second amplifier input. I want a bandpass response only from DABP and output must be the same as I am getting from the amplification stage. Kindly give me some solution for this.
Thanks and best regards
Parag
Part Number:OPA4322-Q1
Hello TI Team,
I am using both of the above op amps (OPA4322-Q1 and OPA2348-Q1). When these op-amps are off ( It is possible that (+) input voltage can go up to 16V through a 49.9k resistor.
This leads to the following questions:
1. I wanted to prevent backfeeding when the op-amp is off and reduce overall quiescent current. Note that the voltage divider circuitry is always hot. Therefore I have the MOSFETs and diode to cutoff the current flow when the op-amp is off. The (+) input voltage will go up to 16V however I don't believe this will damage the parts as I have large input impedance (49.9k) to reduce the input current to the OP-AMP. Please confirm.
2. When the OP-AMP is off (V+ and V- are disconnected) will the output voltage go up to VBATT level? Or will it hold to 0V?
Robert Liu
Part Number:INA210-Q1
