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TPS3307: New design in industrial

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Part Number:TPS3307

Hi,

do you recommend the TPS3307-33DR for a new industrial design or is there an alternative that is similar and newer?

Thanks

Fred


EV2400: EV2400 + WIndows 10: not recognized?!

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Part Number:EV2400

So not sure what to do next...

This EV2400 did work in my colleague's identical laptop also with Windows 10. Unfortunately hes away on holiday..

BAD:

I was testing with the BQ76930EVM, both 'BQ769X0' and 'BQStudio'. neither detect detect the EV2400.

I tried the firmware updated, it doesn't recognize it either.

GOOD:

The LEDs are on

In 'device manager' on windows I see it seems happy (its the bottom entry here)

TPS40210: Current sense and Pulses skipped

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Part Number:TPS40210

Hello,

I designed a Flyback in discontinious mode (2 output + 1 winding for regulation). 

Vin = 20V to 80V

Lp = 19 uH

Freq = 250kHz.

Load max = 1x 3W + 1x5W + 1 winding for regulation

At light load (2.5W) , from Vin = 35V to 80V. The amplitude of the current (measuring Rsense voltage) is not the same at every switching period (alternating between high and low amplitude). At Vin = 60V even some pulse are skipped.

More the load is High, higher the Vin when this "alternated pulses" happen is high. So at mid load (4.5W), this happen from 60V in stead 35V.

Please, can you help to analyse this kind of behaviour ?

Thanks.

UCC28070: UCC28070 GATE waveform issue

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Part Number:UCC28070

Hello Tis

I use the UCC28070 in my 4000W AC/DC project, the input is 185Vac-264Vac, PFC output is 410V

but there are some waveform issues when the PFC output power is greater than 3000W, and causing the PFC MOS damage soon.

could you give me some advive, thx.

(Please visit the site to view this file)

TPS62130: Vin》VOUT voltage

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Part Number:TPS62130

Hi Ti,

    We want to use  4.5V as input ,3.9V as output,is it   meets the   vin》vout  ?

Thanks

Pei yuanqing

LM25141-Q1: Extremely slow startup (~20s) and weak stability under load

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Part Number:LM25141-Q1

Hi,

with the below LM25141 converter we experience unexpected behaviour. Input voltage is 10..30V, output should be 5V (~10A). The circuit has a load-side capacitor with 3F capacitance and about 50mOhms.

We would have expected, that the output voltage raises within about 2 seconds to 5V (at current limit) and then stable 5V is continuously available at the output.

Instead of this the output voltage increases very slowly - within about 20 seconds - to 3V and then raises with about the expected rate to 5V. Once 5V is reached this is weak under load and drops to 4.2V at 3A load. If at power on an electronic load with e.g. 2A preset load current is connected the output voltage does not raise at all.

Picture 1: Circuit schematic (PDF):

(Please visit the site to view this file)

Picture 2: Voltage drop by 0.8V as load steps to 3A (from no load):

red: VIN, white: VOUT, green SS

Picture 3: Startup period with very slow voltage increase:

Any ideas what's mistaken and how to solve this (or what additionally to check).

Kind regards

Arndt

TPS40210: External Slop Compensation.

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Part Number:TPS40210

Hello Team,

My customer is using TPS40210 as boost converter, due to the max input voltage is coming to 72V, so VDD pin can't be tied to VIN but external 12V supply.

1. For RC pin1, can they tied R between RC pin1 and VIN 72Vmax? (RC pin1 abs max voltage has only 10V). any risk?

2. If item1 answer is no, Can they use external slope compensation circuit as attached schematic? after they added the circuit on it, the PWM pulse looks unstable, can you tell why? how to fix this issue?

Thanks,

Martin

(Please visit the site to view this file)

LP8732-Q1: LP8732-Q1 - LDO stability

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Part Number:LP8732-Q1

Hello Team, we have some questions on stability criteria of the LDOs:

Existing design is using output capacitor in total of more than 50uF ceramic.

  • Can we do stability measurements on LDO (similar what we did with buck) but missing feedback pin to do Bode Plot measurements?

  • How can we guarantee stability by given capacitor? According datasheet maximum of 2.7uF is specified

  • What happens when we hit the ILIMIT of the LDO during start-up? Will LDO switch off and re-cover? Which could happen during charging the capacitors.

 Many Thanks

Josef


BQ24610: BQ24610 schematic review

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Part Number:BQ24610

Team,

Customer is going to design BQ24610 in one speaker project. Battery is 2S/7.4V/5200mA. Charge current setting is 2.493A. Pre charge current setting is 0.3A. Iin DPM setting is 2.87A. Below is the schematic. Could you help to review it and let me konw if you have any concern? Thanks.

Asking for alt. solution to replace MP2650 buck boost charger

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Hi team,
Do you have recommendation solution to replace MP2650?

BR,
SHH

BQ34Z100-G1: NTC table

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Part Number:BQ34Z100-G1

Dear All:

    

   we have a plan to use the BQ34Z100-G1  external NTC  function  to monitor the  temperature , and the recommended external NTC  is 103AT.

Now we need to use different NTC, not only 103AT . Is there any method or tool that can help us import the parameter list of NTC we selected? Thanks~

TLV767: Constant current source with TLV767

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Part Number:TLV767

Hi,

I want to build a constant current source with the TLV767. The reason for choosing this part is the enable input, input voltage range, package size and the integrated output pulldown.

My design of the circuit keeps the voltage over the R_SENSE resistor constant. Thus a constant current flows through R_LOAD.

1. What do you think of this design, is it reasonable? It works in simulator.

2. Can you say something about the stability?

3. Is there another circuit example for a constant current source with TLV767 where the load resistor R_LOAD can be connected to GND?


Thank you very much.

BQ24100: Footprint of this IC .

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Part Number:BQ24100

I am looking for the footprint of the above mentioned IC that can be downloaded to PCB123, 2D CAD, Eagle or other downloadable version.

Leonard Roque

Isolux llc sr. engineer.

TPS40210: difference vs webdesign

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Part Number:TPS40210

Hi,

I use the design below from the webdesign (I don't know if the link works)

webench.ti.com/.../SDP.cgi

Some few values are very slightly different (for normalized one)

I encounter a problem to sourcing enough current from this design. The current parameters was selected for 1.5A and I can barely source more than 100-200mA before seeing voltage decrease (with a voltmeter and a LED is used to check that 48V is present, it starts blinking when regulation start to do not works).

I use resistive load for testing, with 100 ohms the problem is clearly visible.

I thought as my power supply was not close to the chip that it was the mainly reason, but adding 47µF close to the initial Cin didn't improve the results.

All components are all grouped on a small area.

Thanks for your help.

TPS61088: Reducing output current when device is in shutdown

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Part Number:TPS61088

Hello, my application is boosting the voltage from 3 'C' cells to 6V to run a motor. Nominal motor current is 200mA but can be as high as 1A when it's close to stalling.

I'm currently using the TPS61088 but I discovered that even when the device is in shutdown it's still outputting ~4V due to an internal diode.

Looks like the only way to cut this current is to use a 2A load switch on the input, right?

Do you have another boost converter that will turn off the output completely? This is important for battery life.

Thanks,

Derek


TPS7A49: Output voltage calculation

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Part Number:TPS7A49

Hello!

Help calculate resistance R1 and R2 for TPS7A4901 and TPS7A3001. I did not fully understand the instruction.


My options:
Input Voltage 25V
Output Voltage 18V
Load Current 100mA

Please show me an example calculation

Best regards,

Sergey

LMZM33606EVM: Regulated output levels change with load current

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Part Number:LMZM33606EVM

I've been testing this regulator (using the EVM with no modifications).  My intent was to simply get an idea of the EMI profile so I could implement filtering input circuitry.

I noted that when I leave the EVM in DCM, with the output set to 5V (and Fsw set to 500kHz) I get different regulated output levels with different loads.

Under each load value (simple resistive loads), the EVM is powered up with the load present and the current and output voltage measured. I had the following results (once again, no changes to the jumper settings between these tests, and no circuit modifications applied to the EVM)

Load = 0.99A; Vout = 5.085V

Load = 1.9A; Vout = 5.118V

Load = 2.76A; Vout = 5.154V

All voltage measurements were made with the same DMM so they will be precise, regardless of the accuracy.

I measured the output voltage both with and without the current measurement DMM in circuit to ensure that the ammeter wasn't impacting the measurements.

The datasheet for the part indicates that it should have a 0.1% load regulation over the entire load range, and I've covered less than half of the range.  

I read through the datasheet to see if I've missed an application setting to maintain the regulation to spec, but can't find that anything is amiss, plus this is the EVM with no changes.

Any recommendations to ensure that the part remains in spec?

BQ76920: BQ76920

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Part Number:BQ76920

Hi, 

I was recently using BQ76920 EVM, during that time I mistakenly connected the reverse terminals (+ve terminal  of battery to -ve terminal of PCB and vice versa). Due to this my Reverse Polarity protection Diode D1 was blown up which I replaced with a new one. Before the mistake the EVM would connect with my PC but since the mistake and I have replaced the diode, it does not connect with PC. kindly assist as to which other components need replacement so that I can reconnect the EVM with my PC

BQ40Z80: RT1 Pulses Clarification

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Part Number:BQ40Z80

Hi Team,

Can you please assist with the questions below from my customer?:

In sleep while monitoring RT1, I noticed that there is a double pulse 28ms from leading edge apart, twice and then a single pulse, where the leading edge of each of the first pulse is Sleep:Voltage Time. For my test Voltage Time is set to 1s. The pulse width of each pulse is 10ms. What is the purpose of the second pulse? Will this affect quiescent current in sleep if it is waking up twice, two out of every three times it wakes up? While the IC is awake, the pulse is single with a width of 18ms (Which correlates to the time between the falling edge of the first pulse and the leading edge of the second pulse while in sleep), with 750ms between rising edges (1.333Hz). 

Thanks,

Antonio

TLC5917: Bus Contention

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Part Number:TLC5917

Hello,

We believe we are seeing a bus contention issue using the TLC5917. Through testing, we were able to determine that the TLC5917 causes SPI bus contention and prevents the DRV9 MCU from reading data back from the CP2400 via SPI. When I scope the signal, I can see the CP2400 is trying to transmit data, but it can’t fully pull the MISO line up to 3.3V or down to ground so I either read back 0xFF or 0x00.

If we remove the IC from the board, this issue goes away. If we just disable all software control of the TLC5917, we still run into the bus contention issue.  

Attached is a scope capture showing the issue. The SPI transaction with the issue is the last one in the waveform (yellow = MOSI, blue = CS of CP2400, green = MISO, pink = SCLK).

Have you run into an issue like this before?       Thanks very much for your help, Keith

  

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