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LM2577: Under voltage lockout

May 3, 2019, 7:54 am
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Part Number:LM2577

I am using the LM2577 to boost a 12V battery to a 15V supply (0.7Amax).  The circuit is pretty much your typical circuit and all works fine 99% of the time. Occasionally upon powering up the IC locks up at about 2.8V. I believe that the problem is due to the main power switch between the battery and circuit bouncing and may be causing the LM2577 to go into under voltage lockout.

Given the information above do you agree that the LM2577 is locking up in undervoltage? Is there anyway to prove it? Have you a tried and tested means to avoid the locking up?

Thanks

Paul

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TLV61046A: Calculating max. ouptut current

May 3, 2019, 8:05 am
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Part Number:TLV61046A

I was wondering if there is a way to calculate the maximum output current for a given output voltage.

When using WEBBENCH I get a failure when demanding a current to high. So I used trial&error to figure out that WEBBENCH is okay with 45 mA @ 27 V from an 3.6...4.2 input. But using the info from the datasheet I fail to get a similar value.

min. Switching Current is 680 mA, so at 3.6 V that are 2.45 W, times 80 % efficiency and divided by 27 V that gives me 72 mA. Where is my mistake?

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TPS2372: Case example for High power Poe solution

May 3, 2019, 8:07 am
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Part Number:TPS2372

One customer start to consider 802.3bt PD over than 125W for TPS2372 or TPS2373.

Is there any information for high power PoE solution below?

①Reference design for over 125W PoE solution.

②Is there success story for high power PoE on Lighting or Building? 

③If there recommended cable for 802.3bt PoE, please let me know.

Best regards,

Satoshi

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TPS23754: Reference design or EVM for PoE+ and 1000base-T solution

May 3, 2019, 8:14 am
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Part Number:TPS23754

Is there Reference design or EVM for PoE+ with 1000base-T solution?

I looked like existing PoE+ designs are 100base-T only.

(For example, TPS23754's EVM, etc) 

If there matched design: PoE+ with 1000base-T the other than TPS23754, it is OK.

Best regards,

Satoshi

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TPS23880: GUI working with EVM, but not with own board

May 3, 2019, 8:22 am
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Part Number:TPS23880

Hi,

when we access the TPS23880EVM with the GUI, then everything works fine.

When we access our own hardware, the GUI reads all registers (tested e.g. by changing the voltage), but it says: "Device not found. Check the device connection or the I2C address configured". So we can't use the Engineering View for debugging our application. In the application by the way we are not able to connect ieee802.3b-devices with Class 6 - on the EMV that's working.

On the TPS23880EVM we have this revision of the IC:

ID(0x1B): 0x55

SRAM-Revision(0x41): 0x01

Device-ID(0x43): 0xC4

On our own hardware we have the following one:

ID(0x1B): 0x53

SRAM-Revision(0x41): 0x40

Device-ID(0x43): 0xC4

Unfortunally we didn't get access to the new firmware yet - we logged some cases, but didn't get any information from mySecureSoftware@ti.com.


What can we do to connect the GUI to our own hardware? Are there version-issues maybe?

Does the IC not come with a valid firmware installed? - Like our ID is lower, but the SRAM-version higher than on the EVM.

What can we do if there is no answer from mySecureSoftware@ti.com (not in the spamfilter, neither), but we need to go into production very soonish and there is actually no time to evaluate another IC.


Many thanks.

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BQ40Z80: FW Version 0.04 Download

May 3, 2019, 9:41 am
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Part Number:BQ40Z80

Hi Team,

Can you please share the .srec for version 0.04 of the bq40z80 firmware? My customer would like to update their devices.

Thanks,

Antonio 

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BQ76925: how to test the IC bq76925 is working or not

May 3, 2019, 9:59 am
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BQ34Z100-G1: Calibrating the BQ34Z100-G1 CC Offset and Board offset

May 3, 2019, 10:55 am
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Part Number:BQ34Z100-G1

Is there any documentation that describes the steps to calibrate the BQ34Z100-G1 via the I2C commands?

For example, if I want to calibrate the CC Offset and Board offset via I2C.

I assume I would be using the commands to calibrate the  CC Offset and Board offset.

CC_OFFSET  0x000A

CC_OFFSET_SAVE  0x000B

CAL_ENABLE  0x002D

EXIT_CAL  0x008D

ENTER_CAL  0x0081

What are the steps to calibrate the CC Offset and Board offset?  Is there anything that needs to be polled during the calibration process to verify the calibration is complete before the data is saved?

Doug

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BQ34Z100-G1: Fuel gauge reset

May 3, 2019, 11:20 am
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Part Number:BQ34Z100-G1

Hello,

we are encountering an issue where in the BQ34Z100-G1 resets time to time and the returned values for the SOC, SOH, voltage etc are all zeros. it immediately resumes after a reset and starts reporting correct values. I checked the reset register by the command "0x05" and it returns 0x00FA indicating that it has been reset 250 times.

Have you encountered anything like this?. Can the learning or impedance tracking or auto calibration cause this? I am attaching the .srec file this is currently programmed. can you please take a look and see if anything obvious comes up?

The design is a single cell pack with INR18650F1L (LG) cell with a capacity of 3200mahr. The CHEM ID is 0x1895.

Control status register is 0x601C(Please visit the site to view this file)

Thank you,.

Gaurav

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BQ34Z100-G1: BQ34Z100-G1 golden image qustion

May 3, 2019, 11:49 am
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Part Number:BQ34Z100-G1

I have two questions related to creating a golden image after the gas gauge has been configured and been through the process to learn the battery and achieve an update status of 6.

Question 1: The documents I have found on the process to create the golden image say to change the update status from 6 to 2 as one of the steps to create the golden image.   Are there any steps that need to be taken after the golden image is programmed on a new device / system before the Impedance Tack is re enabled?  If there are no special steps required, why would it be necessary to set the update status to 2?

Question 2: If there a list of other parameters that should be reset when the cycle count is reset?  I assume anything that says lifetime or any lifetime data would need to be reset. 

Thanks,

Doug

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BQ24610: STAT1 blinking - Charger constantly tries recharging the battery pack

May 3, 2019, 11:30 am
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Part Number:BQ24610

We are seeing a similar phenomena reported by other users at the end of charging.  The STAT1 signal constantly cycles between low and high about every 2 seconds.  The STAT2 signal always stays high.  (STAT1 is low for about 140msec during every ~2 seconds cycle.)

We are using BQ24610 to charge a smart battery pack.  The battery pack uses the BQ40Z50-R2 fuel gauge.  The battery pack has the charge termination current set to 0.35A so that it shuts off charging before the charger does.  (The BQ24610 termination current is set to 0.3A)  The reason is (I am told) that the fuel gauge needs to end the charging process in order to accurately set  the SOC to 100%.

When the fuel gauge shuts off charging,  we believe the charge FET inside the battery pack turns off.  When that happens, the external no-load battery pack voltage drops about 0.5V (diode drop + battery relaxation) lower than the charging voltage.  This voltage is slightly lower than the Vrech threshold, so the battery charger circuit tries to recharge the battery.  But the battery is shut off from charging.  This results in an endless cycle.  We have never seen the BQ24610 outputting the "Charge Complete" status.

1.  What is the best way for the charger IC and fuel-gauge IC to work together and implement charging termination properly?

2. How do we get the BQ24610 to output the  "Charge Complete" status at the end of charging?

3.  The BQ24610 TTC pin is currently connected to a 0.1uF capacitor.  Do you recommend grounding this pin in order to disable charger termination?  Would this help?

4.  Do you offer another charge controller IC similar to the BQ24610 that works better with the fuel gauge IC BQ40Z50-R2?

Thank you...

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BQ76930: Device_xready Fault

May 3, 2019, 12:33 pm
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Part Number:BQ76930

Hello TI, 

We are using the BQ76930 to develop a BMS system. We are able to boot the device properly now but once we boot up, the device_xready bit is set in the Sys_stat register. we tried to clear it by writing to that register but the fault still persisted. I have included the voltages measured at the pins and the schematic. Note that the thermistor R45 on TS1 was removed and remains open, could that be an issue? 

CAP2    =  6.6V
VC5x     =  6.45V
REGsrc = 12.3
CAP1    =  3.28V
REGOUT =  3.3V
BAT       =  12.39V
VC10     =  12.61V
VC6      =  8.44V
VC5B    =  6.36V
VC5      =  6.33V
VC2      =  4.22
VC1      =  2.1V
VC0      =  0.00

Thanks and Regards

Mesfin Bedada

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TINA/Spice/TPS62097-Q1: Spice model accuracy across temp

May 3, 2019, 12:46 pm
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Part Number:TPS62097-Q1

Tool/software:TINA-TI or Spice Models

Hi Team,

I have a customer who would like to understand the accuracy of our TPS62097-Q1 spice model across temperature. Do we have data we can share on this?

Thanks!

Andy

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TPS3839: Preventing uProcessor from Disabling

May 3, 2019, 1:39 pm
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Part Number:TPS3839

I'm using the TPS3839G25 to disable a uProcessor when battery voltage dips below the threshold of 2.325V. The RESET line is directly tied to the Enable line of the uP, it also has a cap, and a 10k pull-up resistor.

When I hook up the uP to the programmer where it's supposed to pull the Enable line low and then back high to reset, it can't quite pull it low enough to disable it when the TPS3839 is in-circuit. I take the TPS3839 out and everything works normally. Not sure what's happening there, any thoughts from the community?

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BQ24297: Customer needs info on RBFET ,when in off state, current is being pulled thru the diode, from VBUS to PMID

May 3, 2019, 2:10 pm
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Part Number:BQ24297

Hi Support team

My customer is using the BQ24297 in a very nonstandard ckt. In one of the modes they will be pulling current thru the RBFET(Q1) parasitic diode (fet is in offstate). This current can be up to 500mA and the ambient temp may hit 65C. Does this present a thermal issue for the part? Can this damage teh part or cause it to lock up or improper operation?

Thanks

Jeff Coletti

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TPS61169: Vfb not regulating to 12.24mV

May 3, 2019, 2:17 pm
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Part Number:TPS61169

We are using the TPS61169 2 per on a design for Loreal.  We are inputing a 6% 6kHZ PWM and expecting 12.24mV on Vfb.  We are seeing units all over the place with regards to Vfb (between 10mV and 30mV.  Our design has 6 IR leds (SIR19-315/TR8) in series being driven.  Can you please help answer why Vfb is not regulating to 12.24mV?  The inductor is a CBC3225T100MR.  Thx

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TPS7H3301-SP: Gm Table - Excel Calculator

May 3, 2019, 5:22 pm
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Part Number:TPS7H3301-SP

Hello,

I am trying to properly use the excel calculator that is provided for this part, but I am running into a few uncertainties. 

  1. The tab containing the Gm lookup table only contains data for DDR1. This is a DDR3 application. I noticed with all the cells populated, if you simply change between DDR1-4, the Gm recommendation does not change...

  2. What's the method for selecting the appropriate crossover frequency?

  3. Is the ESR that gets calculated in the bottom a minimum or maximum value we should have? Or is it simply a target?

Thank you!

Regards,
Ryan B.

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BQ24041: Can I tie !BAT_EN GND?

May 3, 2019, 5:50 pm
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Part Number:BQ24041

I was wondering if I could tie !BAT_EN of the BQ24041 to GND all the time to make the charger start charging when VIN becomes available. Or shall I use !PG with a pull-up resistor connecting to !BAT_EN pin? We don't have any GPIO's left, so we can't control it with our MCU.

Thanks,

-Wataru

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BQ34110: Data memory can not be rewritten.

May 3, 2019, 7:56 pm
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Part Number:BQ34110

environment  
win10
bqstudio V1.3.86 
bq3410FirmwareBundle 0.02
Divice 010.0.02
FULL ACCESS 
The bits of SEC1 and SEC0 are 0.1
Rewriting response  A read data write failed comparison
Is something wrong?
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TPS65295: Power management forum

May 4, 2019, 1:03 am
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Part Number:TPS65295

Dear Team, 

Do we have a suitable solution for DDR4 VR12.5 up to 5A?

If yes, do we have it without SVID?

BR

Kevin

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