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DLPDLCR2000EVM: Spare PCB

August 12, 2018, 3:21 am
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Part Number:DLPDLCR2000EVM

I recently purchased two DLPDLCR2000EVM for a prototype in a project I'm doing. After connecting up my wires, I caused a shortage and burned down some of the chips on the PCB. I thought I made a mistake in the wiring, so I redid everything and double checked. After connecting up the second EVM, the same thing happened. Turns out my power adapter was the actual problem. 

So now I have two projectors, both with unuseable PCB's. I'm guessing the projector itself is the most expensive part, but I have two should still be working fine. Is it possible to order one or two separate spare PCB's? 

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MSP430F249: delay with Timers

August 12, 2018, 4:11 am
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Part Number:MSP430F249

Hello!

its my first time working with the msp430.

i started working on a project that uses the MSP430. an older man wrote  the program for this project and i was asked to fix it.

he didn't know how to use timers so he did a very inefficient delay( a function with a "for" loop)

now i want to use a timer and an interrupt to make it more efficient.

but i dont want to change the original program too much(not yet at least) because it is very long and works.

so i need to have a function of a delay that activates the timer and then puts the cpu in LPM0 and wait for interrupt

but then i am unable to return to "main" to the spot where the delay was issued.

how can i do that?    

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TPS40170: Using Faster FETs results in gate drive oscillations.

August 12, 2018, 5:08 am
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Part Number:TPS40170

Hello,

my question is reguarding the Cin and Cout in my design,

i'm having a ringing problem and would like to implement an RC snubber circuit in my design , in order to prevent the ringing issue,

According to my design, what are the recommanded Capacitance at the input and output stage?

should i cut some caps at the output ? or add some at the input?, what do you think can cause the ringing issue (if you take a look at the desing).?(Please visit the site to view this file)

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DRV8837: What is the efficiency of DRV8837?

August 12, 2018, 5:45 am
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Part Number:DRV8837

Hi,

I saw that DRV8832 has an efficiency parameters but the DRV8837 does not have it.

How can I get these parameters? From a short test I ran I get low efficiency at 5V operation with a 27Khz PWM and 100mA DC Brush motor consumption.

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RTOS/66AK2H14: Resource table

August 12, 2018, 5:53 am
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Part Number:66AK2H14

Tool/software: TI-RTOS

Hi. I created a post two week ago, but no one answered me at the end. Here is the link:

e2e.ti.com/.../712332

Do someone know what is wrong with my resource table?

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RTOS/TIDA-00489: Simulating TIDA with CC1310 and BOOSTXL-TLV8544PIR issues

August 12, 2018, 5:54 am
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Part Number:TIDA-00489

Tool/software: TI-RTOS

Hey guys,

I use the CC1310 Launchpad and BOOSTXL-TLV8544PIR Sensor with the TIDA-00489 Firmware and it basically works. But I am facing some issues and a I have a few questions, since I want to make a few changes to the code. As a sniffer, I am ussing SmartRF Studio with another CC1310 Launchpad.

Issues:

  1. I think there is a loose connection between the PIR-shield and the launchpad, making the device sometimes detect and send motions. I will make a few tests on the cpnnection when I have access to some testing devices, but has this been noticed more frequently before? (it only works, if windows gives me the sound like if I have connected some USB device)
  2. I use "puts" to write some stuff to the console. This only works once in the code. You got any idea why? (the code is below)
  3. I am facing some really strange behaviour regarding when a motion is detected and transmitted via sub GHz.
    1. Sometimes the movement is indicated immediately by sending AA, than FF and then 55 (55 is send after the comparators are both low again) and then further package/s is/are send 8-10s later indicating a movement which does not happen.
    2. Sometimes while I make movements no packages are send, but again 8-10s later they come, although there was no further movement.

--> Any idea, why there is sometimes such a big delay?

4. When I set PIR_QUIET_TIME to 5s, and I constantly make movements 15s long, I see that FF is send like ~20s after AA, like it should. But I don't understand why there are no further AA-packages send after the first detected movement?!

Software changes:

  1. I want to change the program flow, counting the movements and send them after 1min. Therefore, I want to keep the Hwi for detecting the movements and I want to add the Swi to send the #movements each minute. Can you help me create another clock to realize the Swi?
  2. Do you think a Task is better than a Swi for my purpose?
  3. Regarding issue #4 I hope you can help me, because I guess, that the counter won't work, if send_package(AA) does not work either...
  4. What happens to my "move" variable, which I use for counting, when the system goes to sleep, will it stay 0 or will there be some randoom number if I dont initialize it after every wakeup?

This are a lot of questions, but I really want to understand the setup, so that I will be able to use the TIDA-Board properly when I will get it.

Kind regards

Stefan

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BQ25120A: LSCTRL pin: can it be tied to Vcc?

August 12, 2018, 6:23 am
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Part Number:BQ25120A

Hi,

I am designing a circuit with the bq25120a.

I want to be able to control the builtin LDO - both enable/disable it and change its voltage.

My MCU has a limited number of GPIOs.

I would like to "disable" the LSCTRL pin (so it doesn't require a GPIO) and control the LDO entirely from the I2C registers.

My thought was to tie LSCTRL to logic high (Vcc).

On page 43 of the datasheet it is stated that "The LS_LDO output can only be changed when the EN_LS_LDO and LSCTRL pin has disabled the output."

Does that mean that I must toggle LSCTRL to change the LDO voltage?

Thanks,

Michael.



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TPL7407L: TPL7407L drive 12v four-phase stepper motor often appears drive pin is shorted

August 12, 2018, 6:27 am
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Part Number:TPL7407L

Dear all,

Our customer faces a question as following:

TPL7407L drive 12v four-phase stepping motor often has a drive pin broken through short circuit (performance phenomenon is short circuit of output pin to ground, a small part of short circuit to VCC), stepper motor 5-wire 4-phase drive current 400ma, frequency 400pps. The drawings are the same as those provided by the TPL7407L.

Please help us to solve it, thanks!

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DRV2624: DRV2624 motor driving vibration perfermance

August 12, 2018, 6:50 am
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Part Number:DRV2624

Hello,

my customer use DRV2624 to drive motor in cell phone, to achieve vibration effect during words typing. one question from customer is that, the vibration effect of motor is set though our IC driving signal? or just by motor manufacturer? since customer need to adjust the effect of vibration.

currently the design: providing vibration duration time and vibration amplitude, these two interface for upper system to call. then control IC to provide a certain voltage to have motor vibrate.

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WEBENCH®工具/ PGA411-Q1： PGA411-Q1 Vext question

August 12, 2018, 6:51 am
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Part Number:PGA411-Q1

Tool/software: WEBENCH® Design Tools

Hi All,

I have some questions about Vext.

1.Why is the excitation output voltage of 7Vrms mode a range, and this typical value is 14.69 to 24.27V?

2.The maximum output voltage of internal boost power supply is 17V, and the supply VExt cannot cover the entire 7Vrms mode. (17V < 24.27V)，Does VExt need an outside supply?

3.The maximum output power of 145mA excitation current in the technical data, is it a valid value?

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BQ24650: disable charge termination , never stop charging?

August 12, 2018, 6:59 am
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Part Number:BQ24650

Dear TI Expert,

In the datasheet, we can infer that if Pull TERM_EN to VREF to allow charge termination, then the charger will be terminated when current less than 1/10 Fastcharge Current.

So if Pull TERM_EN to GND to disable charge termination, what will happen, charging never stop (STATx always show "Charge in progress")? or charging will stop when current is close to 0?

Is there any risk to disable charge termination ? Thanks a lot

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INA240: Flyback pules effect A1 precision

August 12, 2018, 7:31 am
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Part Number:INA240

Low side inductive current monitoring is prone to Delta V/t transients that should not be part of the amplified output signal yet are very present.

Datasheet header:

The negative common-mode voltage allows the device to operate below ground, accommodating the flyback period of typical solenoid applications.
Enhanced PWM rejection provides high levels of suppression for large common-mode transients (ΔV/Δt) in systems that use pulse width modulation (PWM) signals (such as motor
drives and solenoid control systems). This feature allows for accurate current measurements without large transients and associated recovery ripple on the output voltage.

That latter claim is not exactly true for 240 low side monitoring of rapidly changing periodic PWM CMMV signals.

We noticed INA282 REF1+2 tied to ground seem to block much of the flyback pulses we are seeing on the A1/A2 outputs. These cyclic pulse cycles in sync with PWM frequency (12.5kHz). That seems to hold output settling time above spec and actual sensing inductive CMMV crossing the shunt, thereby effecting SAR 75amp full scaling factor 10mv/A. Reverse or negative current below ground appears to cross PWM rejection circuit and distort the input gain scale set by REF bias pins.  The odd part is the datasheet states REF1+2 tied to GND produces Unidirectional current detection. Yet the scope captures show some inverted pulses in the ratio metric current ramp being created. It would seem that is not entirely true as it relates to isometric monotonic linear gain of CMMV.

1. How is latter possible if inverted (negative) pulses are being created in the positive current measure of so called Unidirectional current flow?

2. How can we mitigate high Delta V/t CMMV input from amplifying signals below ground and or extending output settling time from that condition?

3. Does REF1+2=GND make INA devices ignore voltages below CMMV and shunt idle mode threshold? 

4. Why does the 282 seem to better isolate the differential amplifier from low side monitoring of Delta V/t, AKA inductive flyback?

5. Are there other INA family devices with TSSOP package layout similar to A1 pin out?  

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CCS/TMS320C5535: Issues with dma when running a program from flash boot mode

August 12, 2018, 7:41 am
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Part Number:TMS320C5535

Tool/software: Code Composer Studio

I'm working with tms320c5535, code composer 6, C55XCSL 3.08 and DSP/BIOS 5.42.1.09

my program uses dma for both the sd card and the usb. and while I'm running the program's through the debugger, everything works fine.

however, once I burn the program onto the flash drive so it will boot to the program, the dma starts causing problems.

the sd card will refuse to work and will get stuck inside its CSL functions forever, the usb will stop responding to anything after sending one reply with the dma.

again I have to emphasize that as long as I'm running the code with the debugger instead everything works fine.

does anyone have any idea what might be going on?

*my connector is xds510 usb

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CCS/66AK2H12: How to rename directory in which a project resides

August 12, 2018, 7:47 am
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Part Number:66AK2H12

Tool/software: Code Composer Studio

Under CCSv8, the properties -> rename renames the project;  this is good.

I need to rename the directory in which the project occurs.  The CCS rename does not change the directory name in the workspace.

If I rename the directory (under windows), CCS can no longer deal with or re-open the project.

How does one rename the project AND the directory in which it resides?

Thank you.

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Compiler/TMS320C6657: DSPF_sp_ifftSPXSP_c2r gives wrong results

August 12, 2018, 7:51 am
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Part Number:TMS320C6657

Tool/software: TI C/C++ Compiler

Using DSPF_sp_ifftSPxSP and taking the real part works correctly.  Using DSPF_sp_ifftSPxSP_c2r gives completely different results.

According to this thread: https://e2e.ti.com/support/dsp/c6000_multi-core_dsps/f/639/p/540487/1978321?tisearch=e2e-sitesearch&keymatch=DSPF_sp_fftSPXSP_r2c#1978321

the tw_gen() function is wrong in DSPF_sp_fftSPxSP_r2c_d.c however if I use the new tw_gen() function provided in that thread then none of the FFT functions work correctly.

This begs the following questions:

1. What is the correct tw_gen() code?

2. If the new tw_gen() code in the above link is correct why hasn't the library source code been updated?

3. Why do I have to constantly search the forum for answers to problems rather than being able to refer to included documentation?  Why is the documentation not maintained?

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DAC9881: DAC Output is not consistent

August 12, 2018, 8:03 am
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Part Number:DAC9881

Hi TI team,

We are using DAC9881 for generation voltage as per the requirement .

  Generate below voltages by setting DAC count 1 time

        1. Generated Voltage 1 using DAC - 2.270 approximately

        2. Generated Voltage 2 using DAC - 0.317 approximately

(Please visit the site to view this file)

Issue Observed:

  The DAC output is not consistent. If set the DAC count sometimes i get the expected voltage but sometime i observed lesser voltages.

  I attached  SPI signal for your reference. To analyze the Data , kindly install the below software from the link

https://www.saleae.com/downloads/

Our Analysis:

If we set the DAC multiple times(10 Times with some delay) frequency of occurence of issue reduces. Means output of DAC is almost expected. Very few times it deviates[Lesser voltage]. But it is not good to set DAC multiple times.

Our expectation --> If we set the DAC one time also, it should provide correct voltage as per the count woithout any deviation

  Kindly advice in this situation with high priority.

Thanks and Regards

Manoj

 

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RTOS/CC3220: http server authentication

August 12, 2018, 8:35 am
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Part Number:CC3220

Tool/software: TI-RTOS

Hi,

      when authentication is enabled, the client must provide a username and password before the http server processes any requests.But how the client provide the username and password through user page to http server in Simplelink？which document have explain it?

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AFE4400: formula for Pulse Rate / Heart Rate

August 12, 2018, 9:04 am
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Part Number:AFE4400

From documents we got the formula for SPO2 using AFE4400. But to calculate Pulse rate / heart rate what is formula ? By using the EVM of AFE4400. Please help.

As well as for calibration of spo2 Fluke SPO2 calibrator is only device or is there any other calibrator also available?

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TS5A6542: Switch selecting

August 12, 2018, 9:21 am
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Part Number:TS5A6542

Hi team,

I need to select a 2:1 SPDT and 1 channel switch. Temperature  is -40 to 85 and it will be OK.  90MHZ or 100MHZ  bandwidth will be OK. The input signal is the current that is from 1nA to 1mA.

Then I found TS5A4624. But  I have two questions:

Q1: Since my input signal is the low current, can the low current be used the input signal of  the switch? If not and I also need to use the switch,

do you have any good suggestion for my low input current?

Q2. I need the leakage current should be under pA grade when NC, NO  at ON  status. TS5A4624 cannot meet my requirement. For all my above requirement, could you recommend a suitable device?

Q3. In my application, I need to do a protection design on the input pin of the switch. Because maybe there is the high input voltage that can crosstalk into the  input pin of the switch.

So, how to design the protection circuit?

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DRV8332: Control of BLDC motor for RC

August 12, 2018, 9:25 am
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Part Number:DRV8332

This time I will ask you to use the BLDC motor in robot competition.
Also, because RC ESC has difficulty in controllability, we thought that it would be possible to control it properly by using such an IC.
Since I am a student myself, I can not purchase expensive motor like maxon, so I am thinking that I can use sensorless BLDC motor for RC.
Is it possible to move even with such a motor?
Also, what is the response when turning the sensorless BLDC motor forward and reverse? Specifically, I hope to switch at over 100 Hz. RoboCup requires a considerable response.
If there are other points to note about using BLDC motor for RC, there is something else.
Above, thank you.

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