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BQ24133: choose charge power chip

November 7, 2018, 5:25 am
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Part Number:BQ24133

I want to design a portable device, now choose 7.4V 2 cells 6000mAh lithium battery, the adapter input voltage is12V 3A, Can you recommend a suitable charging management chip? If I want to choose a chip, which parameters are necessarily  i need to know？

in addition, I recently looked at the BQ24133 chip which seems to suit my needs,  I want to confirm that in the case of 2cell, is its output voltage range is between 6V and 8.4v？

Besides ，can you also introduce me a Li-Ion battery fuel gauge like bq34z100-G1  to me ？

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TPS62262-Q1: Missing spec in datasheet for Ton / Toff timing

November 7, 2018, 5:30 am
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Part Number:TPS62262-Q1

Hello Team,

do we have specification for Ton and Toff with min/max spec?

Many Thanks

Josef

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TLV760: POWER UP ISSUE.

November 7, 2018, 5:39 am
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Part Number:TLV760

Support needed for the following circuit:

powering up with a 24V wall mount power supply and powering off and repeating on off on off few times …..the TLV76033 (U$1) will burn… also releasing 24V on it's output destroying all the remaining electronic.

How to go on with this product design ? what's wrong ?

thank you.

Fabio

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WEBENCH® Tools/LM27402: High Current Buck Converter Design: Power Good = Low With Light Load

November 7, 2018, 6:12 am
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Part Number:LM27402

Tool/software: WEBENCH® Design Tools

Hi,

I am trying to design a DC-DC converter capable of sourcing 12A at 2.1V with a 4-13V input.  My design is based on TI’s WEBENCH web app using TI’s LM27402.  The output design from WEBENCH is below.

(Please visit the site to view this file)

I did some modifications to the design from WEBENCH and the final schematic is below.(Please visit the site to view this file)

When bringing up the circuit we saw our designed 2.1V with a power good signal.  I probed the output with a oscilloscope and the result is below (output_1.jpg) where channel 1 is the output. 

Then I applied a 1 ohm load to see how the output would change.  The result (output_load_1.jpg) shows that the LM27402 went into some sort of hiccup mode of periods of switching and rest. 

Further zooming of the signal (output_load_2.jpg) shows that when the buck converter stops switching (where channel 2 is the signal seen on the SW pin), the low side MOSFET is turned off, indicative of an overcurrent event as demonstrated in the datasheet Figure 25.

The issue is that when calculating what our current limit should be, I get around 17.5A using equation 13 from the datasheet.

One issue I thought of is that the time constants with the DCR of the inductor and the RC filter are not matched.  Using the 3.43mohm DCR of our inductor, we should be using a 901 ohm resistor for R_S using equation 12 in the datasheet.  I am using 845ohms.  Could R_S really be that sensitive?

I tried changing R_SET used for setting the current limit and observing the output.  The observations are below:

R_SET (ohms)

V_OUT

Power Good

Notes

3.7k

1.82V

0

Unstable output

5.1k

2.0V

0

Unstable output 

10k

2.08V

1

Source < 330mA before entering hiccup

16k

2.08V

1

Can just barely source 330mA.  Needs some sort of load to achieve designed output voltage.

>50k

1V to 5V

N/A

Unstable output going from overvoltage event to undervoltage event

Would anyone have an idea of what is going on?  I am happy to provide any information/data necessary for your analysis.  I hope to hear from you soon.

Warm Regards,

Nick

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LMZ21700: LMZ21700 EMI Protection

November 7, 2018, 6:18 am
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Part Number:LMZ21700

Hi,

We're designing a product with LMZ21700. For EMI tests, we shielded the power block with RF shield. Before the power block, we have LC filter, which is BNX026H01L. Should we also use shield for our LC filter for EMI tests ? 

Thanks!

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BQ24650: STAT 1 and STAT 2 line

November 7, 2018, 6:37 am
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Part Number:BQ24650

HI Team, question attached

(Please visit the site to view this file)

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Discharging the battery with the Bq25703A module

November 7, 2018, 6:45 am
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Hi,

I am using bq25703A for the battery Charger. I manage to establish a communication between this module and the card STM32F4 .
The communication is well established and I manage to write and read data in the registers of bq25703A also I manage to charge a battery that consists of 3 cells now I try to unload the same battery.
I followed the activation steps of the OTG and I finally succeeded, but my initial problem was the discharge of the battery.

When I activate the OTG the discharge will be done directly or it is necessary to add a charge.

If yes, how can I add the charge? in the datasheet there is a part that says "The device supports USB OTG operation to deliver power from the battery to other portable devices through USB port "but where is the USB port I do not see?

Regards,

Mohamed

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TPS2546: Asking for the TPS2546 schematic review

November 7, 2018, 7:03 am
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Part Number:TPS2546

Hi team,
custome rowuld like to use TPS2546 on the PC.
could you please review the schematic and provide your comment?

BR,
SHH

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UCD3138128A: Programming the UCD3138128A

November 7, 2018, 7:11 am
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Part Number:UCD3138128A

Hi,

I stand slightly confused. Maybe someone else can clear the confusion that I am having.

My basic question is, how can the UCD3138 be programmed ?

Is it possible to program the UCD3138 using the XDSxxx programmers, or does it require the USB serial adapter/Flash Runner itself ?

(Saw a few places that the XDSxx supports the UCD3138 and hence the query)

Thanks,

Manu

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TPS568215: Switching frequency tolerance

November 7, 2018, 7:16 am
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BQ2970: Vss connect to GND or Cell-

November 7, 2018, 7:05 am
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Part Number:BQ2970

Hi Team,

I am confused about the relationship between Vss, cell-, pack- and Gnd.

Vss connect to GND in EVM, but connect to cell- in data sheet typical application. What is the different?

We use coin battery, and the schematic connect Vss to BAT-, is this correct?

Thanks

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BQ2970: Vss connect to GND or Cell-

November 7, 2018, 7:06 am
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Part Number:BQ2970

Hi Team,

I am confused about the relationship between Vss, cell-, pack- and Gnd.

Vss connect to GND in EVM, but connect to cell- in data sheet typical application. What is the different?

We use coin battery, and the schematic connect Vss to BAT-, is this correct?

Thanks

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BQ2970: Vss connect to GND or Cell-

November 7, 2018, 7:11 am
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Part Number:BQ2970

Hi Team,

I am confused about the relationship between Vss, cell-, pack- and Gnd.

Vss connect to GND in EVM, but connect to cell- in data sheet typical application. What is the different?

We use coin battery, and the schematic connect Vss to BAT-, is this correct?

Thanks

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BQ25606: do external discharge FET additional possible ? as like BGATE function for peak Ichg consideration

November 7, 2018, 7:44 am
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Part Number:BQ25606

Hi Sir,.

do external discharge FET additional possible ? as like BGATE function for peak  Ichg  consideration,..

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BQ25882: Datasheet Request

November 7, 2018, 7:49 am
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Part Number:BQ25882

Dear TI,

I put in a request for the bq25882 Datasheet over a week ago, but have not heard back.

Does it normally take that long to process the request?

Regards,

Kevin

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TPS2378: TPS2378 +TPS54360 Poor power supply

November 7, 2018, 8:13 am
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Part Number:TPS2378

hi  sir/madam,

   

Now I have made a router case, using POE power supply (TPS2378+TPS54360), the power is greater than 30W. Now I use two TPS2378+TPS54360 to power the system. Now the following situation appears:

1. When I use the switch to supply power to the router, first I plug in one port(Please visit the site to view this file) and the power is normal. When I plug in RJ45 to supply power to another port, the system will lose power, and the power will be recharged at a interval of 2 seconds

2. This will not happen when I use two switches to supply power to two ports. When the two switches were connected together, there was a situation like 1.

Attached is the schematic diagram, please help to see if there is any change to improve this situation, thank you ~~~

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TINA/Spice/LMG5200: Request to provide LMG5200 unencrypted spice model

November 7, 2018, 8:19 am
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TPS7H2201-SP: Commercial pendant

November 7, 2018, 8:33 am
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UCD3138128A: Looking for CAD files

November 7, 2018, 9:13 am
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Part Number:UCD3138128A

Hi,

I am looking for the CAD (.bxl) file for the UCD3138128A chip, but cant unfortunately find it.

Is a bxl file available, someplace that I am unaware of ?

Thanks,

Manu

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LM2698: Is the output stable even when no load are powered?

November 7, 2018, 9:26 am
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Part Number:LM2698

Hi,

I was wondering if the output of the LM2698 stayed stable even when no load were powered?

Thanks for your time,

JN

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