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BQ78350-R1: Cannot communicate with EV2400

July 10, 2019, 5:29 pm
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Part Number:BQ78350-R1

I made a board of EV2400 and a part of BQ76940EVM by refering the schematic in the user guide of them.
However I could not communicate with BQ78350-R1 from bqstudio.

I could communicate with EV2400 board and could see the version of it (0.28). All leds lit.
And I measured the voltage of some point as follows. They looks fine, I guess.

[EV2400]
VCCs of MCP430 : 3.3V
High side of Pullup R (SMBC/D output) : 2.4V

[BQ76940EVM]
REGOUT of BQ76940(=VCC of BQ78350-R1) : 2.5V after BOOT
BAT of BQ76940 : 45V (applied)

Would you advice anything ?
Thank you in advance.

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LM7800:

July 10, 2019, 2:02 pm
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Part Number:LM7800

1) Dual output voltage circuits with 79xx and 78xx are common and stable circuits. Somemanufacturers also suggest  negative output voltage circuits with 78xx.

2) Is it possible do develop stable and effective dual output circuits by using two 78xx one with positive output settings other with negative output settings

e.g. 24 V DC input, voltage divider with two 100K resistors between +24 V and grd. 

one 7812 with possitive settings and other 7812 wth negative settings.

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UCC27712EVM-287: 2.2 ohm resistor on Vcc is a significant source of loss when low-side gate turns on?

July 10, 2019, 2:36 pm
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Part Number:UCC27712EVM-287

I was doing testing with this eval board and found my synchronous buck supply was failing to regulate under both high load or high input voltage conditions. I was sometimes triggering the UVLO for the Vboot and the Vdd. Vdd was dropping down to 8V.

What I found was that I had a steady 4V drop across R1 when I supplied 12V to Vcc. It appeared that since Vdd fed both U1 and the Vboot diode (and R2), Vdd never recovered since a gate is always being driven. 1.8A from the measured 4V drop is within nominal drive current for the chip. 

Why is a 2.2 resistor used? It seems high considering peak current of the driver. Wouldn't it be better to split up Vcc to feed Vboot and Vdd first before the resistors? Then the caps can recover the rail when the other side is active?

Please note, I only see this behavior under load, so it indicates the drive current being the culprit. Bypassing the R1 resistor improved performance under high input voltage conditions indicating that the low side was turning on correctly.

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BQ24210: Proper way to disable LPCM through TS and VTSB pins

July 10, 2019, 2:52 pm
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Part Number:BQ24210

I would like to use a BQ24210 to charge a Li-Ion battery from a small solar panel.

Solar panel: 5V, 30mA

Battery: 18650 3.7V 2200mAh, no thermistor

Question 1:

I intend to operate in LPCM by tying TS high as directed in the spec.  However, I am not sure what to do with VTSB.  Do I just tie VTSB to TS and let it pull TS high?  Would I need any other biasing?  Is it better to separately tie TS high and let VTSB be unconnected?

Question 2:

What would be the expected charge time for this combination?

Question 3:

If I decide the charge time is excessive, what would be a better charge controller to use with this solar cell and battery?  What would be the charge time for the recommended controller?

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LM317-N: 197 SVHC reach statement

July 10, 2019, 3:20 pm
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Part Number:LM317-N

Can someone help me to get the updated 197 SVHC reach statement for the texas instrument component LM317T/NOPB??


In advance thank you for your help and support.

Best Regards.

Gabriel

 

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TWL6040: New version or similar function

July 10, 2019, 6:25 pm
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Part Number:TWL6040

Hi Sirs,

Sorry to bother you.

Because  TWL6040A3SRSZQZ was NRND, does TI have new version or similar function IC can replace?

Thanks!!

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LM5111: LM5111

July 10, 2019, 6:40 pm
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Part Number:LM5111

Hi

I'm designing a synchronous CUK converter and I want to replace the rectifying diode with a P-channel mosfet so I will have a N-channel mosfet and a P-channel mosfet. I want to use LM5111 gate driver ic to drive the switches but based on the datasheet, this ic has been designed to independently drive two N-channel mosfets. My question is that is it possible to use this gate driver ic (LM5111) in my application? Is there any way for this gate driver ic to drive a P-channel mosfet? If so, what kind of considerations should i take into account? Furthermore, using this gate driver ic (LM5111) , is there any way to program the dead time externally? As this ic does not have a programmable dead time feature. The files attached below are the datasheet of the mosfet that i'm using and the power stage schematic.

(Please visit the site to view this file)(Please visit the site to view this file)

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CSD87502Q2: Please provide the Pin Configuration and Functions of CSD87502Q2.

July 10, 2019, 6:42 pm
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Part Number:CSD87502Q2

Dear Sir,

After I read the datasheet of CSD87502Q2, I couldn't find the Pin Configuration and Functions of CSD87502Q2. The datasheet only mentioned the top view of package,

but I couldn't know each pin number which should be met each number of Drain, Gate and source. And when I read the Package Dimensions page it only mentioned pin 1

, pin 3, pin 4 and pin 6, so I know rest of pins. Please provide the Pin Configuration and Functions of CSD87502Q2 such as the picture below for reference.

Best regards,

Rudy Tsao

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BQ27520-G4: The specification of pin

July 10, 2019, 6:59 pm
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Part Number:BQ27520-G4

Dear all,

I would like to know about pin function of BQ27520.

If there is an open between E2 and GND, or between D2 and GND, what happens to the IC's operation?

(In particular, what happens to I2C communication and output operations.)

It would be great if you could let me know your thoughts on the following a question.

Best Regards,

Y.Ottey

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TPS53667: TPS53667 VIN UVLO SETTING

July 10, 2019, 7:09 pm
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Part Number:TPS53667

TPS53667 VIN UVLO SETTING, when i want to set the 5V vin  UVLO , how to set the register address of MFR_SPEC_16[1:0] ,thanks!

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WEBENCH® Tools/BQ25101: how to connect LED to the charger chip BQ25101

July 10, 2019, 7:11 pm
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Part Number:BQ25101

Tool/software: WEBENCH® Design Tools

we are using BQ25101 in our design. how to connect LED to the chip to indicate charging state and fully charged state.

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TINA/Spice/UCC23513: UCC23513 TINA model

July 10, 2019, 7:57 pm
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BQ27426: Bq27426G1 question

July 10, 2019, 8:19 pm
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Part Number:BQ27426

Hi :

1. my project have the low temperature request(-15), if i need use the GPC to do the CHEM ID Ra & Rb matching and get the CHEM ID, can you teach me how to load it in this gauge.

2. i already use the default ID 1202 to finished the learning cycle test, the DFI setting is follow the customer request and battery SPEC, i found the Qmax & Ra have changed but the update status still is 0, may i ask the update status will automatically become to 2 or need manual adjustment?

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UCC38503: UCC38503 : Abnormal AC input current when no load

July 10, 2019, 8:19 pm
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Part Number:UCC38503

Hi Ti ,

I use UCC38503 as a PFC + forward power module design which rated output power is 300w. When output no load , the AC input current will become abnormal. The current waveform like inrush current when power on. The input AC current become normal when I connect very light load on the forward side, for example 3W load. Is that because the poor compensation of PFC or or current shunt? 

Attached files is my circuit of PFC and abnormal waveform. 

thank you very much

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CCS/UCD3138: In UCD3138 how to make Filter control the dpwm period?

July 10, 2019, 8:21 pm
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Part Number:UCD3138

Tool/software: Code Composer Studio

In UCD3138 how to Configuration Register make Filter output effect the dpwm period?

Have some easiest sample code for teaching? Like TI Lab_4 Code witch show me how to Configuration Register to make Filter output effect the dpwm duty。

I have tried to Configuration some Register like:
Filter0Regs.FILTERCTRL.bit.PERIOD_MULT_SEL = 1;
Filter0Regs.FILTERCTRL.bit.OUTPUT_MULT_SEL = 3;
and so on .But it dose't work.

I really hope that have more easiest  demo code can help me to learn the ucd3138 function

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BQ76920: timing of cell balance function relative to configuration register write to enable and disable

July 10, 2019, 8:25 pm
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Part Number:BQ76920

Hi, we are using cell balancing function in a way where timing of enabling and disabling function is important.

Although the datasheet doesn't seem to explicitly mention, the timing observed is as follows:

* Enable cell balancing: a BQ 250ms interval completes (ALERT is asserted by BQ), immediately issue request to enable cell balance through I2C reg write (~ms latency). On O-scope, enabling is observed to occur the next 250ms interval.

* Disabling cell balancing: a BQ 250ms interval completes, immediately issue request to disable cell balance through I2C write. Disabling observed to occur the current 250ms interval.

Is this known behavior, to have non-uniform enabling / disabling behavior? If this is known, any guidance on how we can make sure this is always the case? Basically if enabling/disabling is off unexpectedly by a 250ms service interval, it may impact behavior of the system. Of course it is also possible we are misinterpreting the behavior, so guidance on expected behavior is helpful.

Thanks

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TPS59641: Question about the SVID control of VCC_GFX (VNN)

July 10, 2019, 8:25 pm
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Part Number:TPS59641

Dear Sir

We use TPS59641 as the VR solution for Intel Celeron Processor J1900.

Acoording to the datasheet of TPS59641, both VCC_CPU(VCC) & VCC_GFX(VNN) should be able to been controlled.

However, we found the VID Table of VCC_GFX(VNN) is fixed in the Intel Gen4 VR test tool ( VCC_CPU rail is fine to control VID)

Whcih means we can't change the VID parameter of VCC_GFX

Do you have any idea about this issue?

Thank you very much.

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TPS63000-Q1: TPS63000-Q1 for AEC-Q100

July 10, 2019, 8:28 pm
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Part Number:TPS63000-Q1

Hi Sir,

      TPS63000IDRCRQ1 datasheet only show this description "Qualified for Automotive application",

We need to note the documents with AEC-Q100, Please help to provide,  thanks

Sincerely

Kevin

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LM5176: broken when buck mode

July 10, 2019, 8:33 pm
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Part Number:LM5176

Dear Ti Experts,

My customer is debugging LM5176, the input voltage is 12~24V, and output is 20V, below is schematics, they found it worked well when in boost mode, however, it is very easy broken in buck mode, sometimes, the MOSFET would broke in bukc mode also, could you kindly help to review and give some advices? Thanks a lot.

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Asking for the recommendation 100Watt power source switch

July 10, 2019, 8:37 pm
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Hi Team,

Customer is looking 100Watt power switch on type c power provider application. 

Here are customer requirement.

  1. Can meet PD 100W.
  2. Have OVP/OCP/UVP function.
  3. MUST have CB/UL certificate. 

Would you please recommend the proper solution for this?

BR,

SHH

 

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