Quantcast
Channel: Data converters forum - Recent Threads
Viewing all 5988 articles
Browse latest View live
↧

12-Bit low power SAR ADC with bipolar input

September 4, 2019, 4:54 am
$
0
0

Hello!

After i have spend quite a few hours inside the ADC product search tab without success, I decided to ask by question here in the forum:

For a project I am searching for a low power 12-bit SAR ADC capable of sampling bipolar inputs. The source I have to digitalize has a voltage range from -0.5V to 3.7V (<100Hz). I also thought of creating an opamp stage with DC offset and gain attenuation to scale the source voltage range into a microcontroller ADC FSR of about 3.6V. The problem with this approach is calibration and long term stability. So I am trying to search for an external ADC that will have no problem converting the specified source voltage range.

I would be very glad for some recommendations.

best regards

Benjamin

↧
Search

ADS1299: ADS1299EEG-FE BIAS jumper selection for internal BIAS generation

September 4, 2019, 5:44 am
$
0
0

Part Number: ADS1299

Hi all, 

I am trying to evaluate the ADS1299 using the ADS1299EEG-FE eval board. How should I set the jumpers to achieve this? I am trying to follow the schematic, but cannot make sense of it, as I can't see where the BIAS_DRV port goes to / comes from. 

Thanks for your assistance, 

Sam

↧
↧

TSW14J57EVM: TSW14J57EVM

September 4, 2019, 6:42 am
$
0
0

Part Number: TSW14J57EVM

Hi,

I am trying to load an external pattern file in HSDCpro. The file is an LTE file with sample rate 491.52M ans the input data rate field in HSDCpro is also 491.52M. But still I cannot see the spectrum in spectrum analyzer . Also, in my case, I am using AFE7686EVM which has TSW14J57 as the data capture card for DAC. I dont know what is the problem. please help in order to resolve this issue. It is two column .tsw file with I and Q data. 

Thanks & regards,

Debalina

↧

DAC7578: DAC read sequence on input register

September 4, 2019, 7:40 am
$
0
0

Part Number: DAC7578

My team is using the DAC7578 12-bit, 8 channel device on a custom board. Prior to the custom board prototype, I have been using the DAC7678 EVM for development. I am experiencing some unexpected issues in the read sequence of the DAC7578. Please see the attached snapshots of the captured I2C byte sequences to the two devices.

DAC7578:

DAC7678:

The test sequence on both devices is:

1. Power up all DAC channels (Power Down Register 0x40; PD1 = PD2 = 0; all channels selected)

2. Write full count to DAC Input register Channel D and update all DAC registers (Global Software LDAC: 0x20; Channel D: 0x03; Full count: 0xFFF)

3. Read back DAC input register D (0x03)

However the read-back from DAC7578 does not reflect the full count written to it, although the voltage on Channel D is observed correctly, at full reference value.

What is the difference between DAC input register and DAC register for each channel?

Which register should be read back in software?

What might be causing the discrepancy in the read back between the two devices?

↧

ADS1158: How to connect Differential input

September 4, 2019, 7:43 am
$
0
0

Part Number: ADS1158

Hi Sirs,

Sorry to bother you.

We saw all of document (EVM, Datasheet) on ADS1158 are signal-end input type.

But we will use Differential input.
So could you give us some suggestion or have reference schematic can follow?

Thanks!!

↧
↧

AFE4900EVM: Oxygen saturation with different pigmentation of skin

September 4, 2019, 7:59 am
$
0
0

Part Number: AFE4900EVM

We have an eval board but need to learn how to get accurate SpO2 values, particularly when we do a hypoxia study down to 70% oxygen saturation and with different pigmentation of skin.  Do you have resources in developing the algorithms for that study?

Thanks,
Nick

↧

AMC7932F - 2

September 4, 2019, 9:07 am
$
0
0

(Please visit the site to view this file)

↧

ADS54J54EVM: Question about JESD204B data lanes length match

September 4, 2019, 9:19 am
$
0
0

Part Number: ADS54J54EVM

Hi,

In the schematics of  ADS54J54EVM  page 4 it ca be read: 

"HIGH SPEED DIFF PAIRS
DA*, DB*, DC* & DD*
DO NOT HAVE TO MATCH EACH OTHER IN LENGTH
THE P & N ON EACH PAIR MUST MATCH IN LENGTH"

But when I look at the PCB tracks for these signal they are in fact matched in length with each other as can be seen below. I am doing a board with exactly the same configuration that is trying to connect to a FPGA through FMC connector, how should I do?

Regards/Ramin

↧
Search

ADS1232: ADS1232

September 4, 2019, 10:34 am
$
0
0

Part Number: ADS1232

Hi everyone, 

Currently, i'm designing an industrial weith scale with a maximun weight of 15 tons (6 load cells of 3 tons each connected in parallel). The main requeriments are a resolution of 50 kg approx. (easy for 24 bit resolution) and thermal stability.

I have been testing the ADS1232, but my prior results are really bad, with a high noise level (compared to the results of the HX711). In my previous configuration i didn't consider filters for the analog signal. 

My question is, is the ADS1232 a good choice for this application, considering the thermal stability? Are analog filters critical for the application considering that the HX doesn't use it?  

As i can see in the diagrams of the ADS1232REF user's guide, are filters used for digital signals, is it necesary? 

Thanks you! 

  

↧
↧

DAC8750EVM: DAC8750EVM

September 4, 2019, 1:30 pm
$
0
0

Part Number: DAC8750EVM

software installation issue,

I am getting (attached) error message when I try to run the s/w (just downloaded, sboc432b)

↧

ADS1218: Return from PWDN timing

September 4, 2019, 1:53 pm
$
0
0

Part Number: ADS1218

We are using the ADS1218 (and the ADS1243) in both chips there is a /PWDN pin that we use to shut down the part to conserve power.  My question is how long after raising /PWDN is the chip ready to use?  There doesn't seem to be a specification for this in the data sheet.

Thank you.

Paul Mayer

↧

ADS8688: Almost every customer uses AD7606 in Grid Infrastructure products(DTUs, FTUs...), ADS8688 has only 8 chananls while AD7606 has 16 channals, does TI have any update to beat AD7606 in the future?

September 4, 2019, 7:39 pm
$
0
0

Part Number: ADS8688

Almost every customer uses AD7606 as an AFE in Grid Infrastructure products(DTUs, FTUs...), ADS8688 has only 8 chananls while AD7606 has 16 channals, does TI have any update to beat AD7606 in the future? As AD7606 is a very old product and had been used for years.

↧

DAC8568: DAC80508EVM software installation problems on Win'10 64 bit.

September 4, 2019, 8:39 pm
$
0
0

Part Number: DAC8568

Hi, (Paul)

I've received USB2ANY and DAC80508EVM. Thanks.

It is not possible to run EVM software due to NI RunTime engine installation problems.

I've tried NI RunTime package versions (32&64bit) from 2014 to 2019. No effects.

After installation NI soft the message is always as in attached file.

I use Win'10 64 bit.

Regards

Andrzej

(Please visit the site to view this file)

↧
↧

DAC53608: DAC53608 – About powered down (10K to AGND) of DAC output amplifiers

September 4, 2019, 9:48 pm
$
0
0

Part Number: DAC53608

Hi Team,

 

We would like to know about powered down (10K to AGND) of DAC output amplifiers status.

I understand that the resistance level between VOUTx and AGND is 10kΩ at Low Power Startup Mode.

Is my understanding correct?


 

Regards,

Kanemaru

↧

ADS5263EVM: ADS5263EVM

September 4, 2019, 10:47 pm
$
0
0

Part Number: ADS5263EVM

Hello,

I have a question about Vcm in ADS5263EVM. In datasheet for ADS5263 I see the recommended common-mode voltage = +1.5V (+-50mV), and for THS770006 this voltage needs to be from +2.25V to +2.75V. However, in datasheet for ADS5263EVM (on page 38) Vcm = +2.5V. And this +2.5V goes to the ADC pin.

 Am I correct, that it's permissible to apply more voltage to the ADC's Vcm pin, than +1.5V? Could you explain please, why does the Vcm voltage affect on the lower limit of the ADC frequency? 

Sincerely,
Alena

↧
Search

DAC7760: DAC7760 voltage and current output problem

September 4, 2019, 11:44 pm
$
0
0

Part Number: DAC7760

i'm trying to use dac7760 with STM32f1 and this is my schematic

I use the following function to send data from STM32f1 to a DAC7760:

static HAL_StatusTypeDef WriteSingle_DAC7760(uint8_t ch_Addr, uint16_t ch_Data){     
  uint8_t liv_Data[3]; // 0: ch_Addr  1:ch_Datadata?8? 2:ch_Datadata?8?
  uint8_t liv_RXData[3] = {0};
  liv_Data[0] = ch_Addr;
  liv_Data[1] = (ch_Data & 0xff00) >> 8;
  liv_Data[2] = ch_Data & 0x00ff;
  status = HAL_SPI_TransmitReceive(&hspi2, liv_Data, liv_RXData, 3, 500); 
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_3, GPIO_PIN_SET);
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_3, GPIO_PIN_RESET);
  HAL_Delay(1);
  return status;
}

I use this initial settings for DAC7760

//Write reset register
WriteSingle_DAC7760(0x56, 0x0001);

//Write control register 1001 0000 0000 0001  
WriteSingle_DAC7760(0x55, 0x9001);

//configuration register 0000 0011 0000 0000
WriteSingle_DAC7760(0x57,0x0300);

WriteSingle_DAC7760(0x01,32000);

there is no output on current output and voltage output. Am I missing a part or did I do something wrong?

↧

TSW1400EVM: Failed to program FPGA

September 5, 2019, 1:25 am
$
0
0

Part Number: TSW1400EVM

Hi,

Upon verification of TSW1400EVM’s behavior with the High Speed Data Converter Pro software, it was found that the firmware downloading procedure fails. Are there any potential root cause for seeing this error?

What was done:

  1. Supplied 5V, regulated power at J12
  2. Connected USB cable from a host PC to J5
  3. Turned on SW7
  4. Connected to the board on High Speed Data Converter Pro v5.00
  5. Tried to program the FPGA by “Download Firmware” menu

What was observed:

 After the programming procedure ends on the GUI, the software says “No firmware. Please select a device to load firmware”, and the on-board LED “FPGA_CONF_DONE” is still OFF, indicating the FPGA firmware is not correctly written.

I further checked that the programming procedure is successfully done, when I temporally remove the DDR-SDRAM on J6. Then I can do “capture” on the software, but all the sampled data is just zero. Could this error be linked to the onboard SDRAM?

Regards,

Leo

↧
↧

ADS7952-Q1: The sampling accuracy

September 5, 2019, 2:22 am
$
0
0

Part Number: ADS7952-Q1

Hi,

Please help me with the following questions about the sampling of ADS7952.
The current project is 800V high-pressure acquisition, and ADS7952-Q1 adopts manual mode for channel selection.
1. When the sampling channel 0 is not applied with voltage, the upper computer can read the multiple voltage of 0.45v. When running out and applying voltage, the collected voltage value is added with this initial read voltage value;
2. When each line is collected separately, the collected voltage is smaller than the theoretical voltage value, which is a multiple of 0.45v;
3. Manual mode will have an impact on the sampling of adjacent channels. When two channels are connected at the same time, the voltage of the lower one will be larger than that of the upper one.
4. The higher the voltage, the larger the voltage error collected by channel 1 will be

data:

We are using 2*REF now. When channel 0 is not connected to 63.2v, the upper computer reads 0.25432v voltage or twice or three times of runout. After connecting 63.2v, the voltage is about 63V.
When the single channel 1 connects to 63.2v, the voltage around 61V can be picked up.
When the single channel 2 is connected to 63.2v, the voltage around 61V can be picked up.
The rear channel connected separately is similar;
Channel 0 and channel 1 are connected to 63.2v at the same time. Channel 0 can pick up the voltage of about 63V, while channel 1 can pick up the voltage of 62.5671v.
Channel 1 and channel 2 are connected with 63.2v voltage at the same time. Channel 1 can pick up about 61V voltage, and channel 2 can pick up 62.5671v voltage. Adjacent channels will have an impact.
When channels 0, 1 and 2 are fully connected to 63.2v, if channel 0 is about 63V, 62.5671v can be obtained in channels 1 and 2.
The error sizes between channels are all multiples of 0.25432v.

Thanks!

↧

AFE4900: Sample ppg signal

September 5, 2019, 2:33 am
$
0
0

Part Number: AFE4900

Hi,

AFE4900 has 4 leds and 3 pds, led3 or led4 is used to sample ambient light,  but I want to use 4 leds to sample ppg signal , is there any problem?

↧

ADS42JB69: Automation Dll or Automation API to automate the changes to ADS42JB69 using a python script.

September 5, 2019, 3:55 am
$
0
0

Part Number: ADS42JB69

Hi team,

Is there anyway to automate the ADS42JB69E just like HSDC pro automation dll or automation API using python script or just like LMX2594 by binding the tics pro .tlb file to python and automate?

I want to either automate the ADS42JB69E GUI or directly change the values on the ADS42JB69 Board(hardware),either way is fine.

The complete idea is to automate the complete process what we do manually, my setup consist of 4 parts

1.ADS42JB69E 16bit and its gui

2. TRF371109 IQ demodulator,

3. LMX2594 and its gui(TICS pro) and,

4. TSW14J50 Data capture and its gui HSDC pro.

On all this parts i am manually making changes through there GUI(HSDC pro GUI,TICS pro GUI,TRF3711 GUI,ADS42 GUI), All these changes I want to Automate using the python script.

One i already found for HSDC pro using the automation dll files , similarly i am looking to automate rest 3 GUI part number devices as mentioned above, please do suggest if there is anyway to do that ?

Automation scripts for HSDCPRO are available in the following location:

C:\Program Files (x86)\Texas Instruments\High Speed Data Converter Pro\HSDCPro Automation DLL\Manual and Examples

For any clarification on the above details plz do let me know ?

Thank-you in advance 

Rakesh Chahar.

↧
Viewing all 5988 articles
Browse latest View live
Search
<script src="https://jsc.adskeeper.com/r/s/rssing.com.1596347.js" async> </script>