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TPS61170: outside inductance confirmation

December 9, 2019, 7:33 am
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Part Number: TPS61170

Hello team,

About the TPS61170 I  would like to ask you for clarifications regarding the coil.
Based on our requirements:
Vin: 6V - 12V
Vout: about 14V and Iout=140mA.

From calculations it should be around 47uH, but on the excel spreadsheet with this value I get as result the following suggestion: “Inductance outside tested range. User responsible for confirming control loop stability ”.
So I would like to ask you what it actually means, I can still use a 47uH using the stability calculations proposed on the file, or it is better to reduce the value of the coil?
Please let me know your thoughts.
Best regards,
Adrian
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BQ40Z50-R1: BQ40z50 PBI PIN function

December 9, 2019, 7:34 am
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Part Number: BQ40Z50-R1

Hi team,

If we short the PACK+ to GND, will the PBI pin CAP provide a transient back up power to make bq40z50 protection fuction work well?

If we assume the BAT pin votlage is also 0 when short circuit happened, how long will the PBI CAP make the bq40z50 work well？What will bq40z50 do at last, to store some RAM?

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BQ40Z60: negative value of "true Rem Q"

December 9, 2019, 7:42 am
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Part Number: BQ40Z60

Hi all,

please could someone help answering/comment following points for customer:

1. Why does the parameter "True Rem Q" become negative when discharging the battery pack; the value reaches an average of -300 to -400mAh

  •  From which parameters does it depend that this value becomes negative?

 

2. Current calibration: We have calibrated the current at the “0-point” to 0 and -2A to -2A (Discharge) - in between the measured value is linear within the tolerance range

  •  Unfortunately, there is only one common calibration value for Charge and Discharge
  •  Charge mode but results in a different slope than in Discharge. As a result, although I can correctly measure the Discharge current, but the charge current is displayed by about 3% too high.(shunt resistance has no effect, balancing has been disabled for these investigations)

 

3. Current peak at the batch start

  • The BQ40Z60 SYSPRESS function is used and the CHARGER_EN bit is permanently set
  •  First connect the battery pack to the device (SYSPRESS = active)
  • Then apply a voltage at the input of the charger (for example 12V for batch of a 2s pack)
  •  Subsequently, the voltage at the input of the charger is interrupted for a short time
  • After re-applying the input voltage, the charger will start fully and charge the battery for 1-2ms with approx. 6A (peak current depends on the input voltage)
  • This triggers the error ASCCL
  • Repeating this process, but before disconnects the battery pack for a short time from the device (SYSPRESS briefly inactive), this error does not occur
  • Remedy: Set the CHARGER_EN bit to INACTIVE by default and only activate the CHARGER_EN bit by SW when the input voltage is clean at the charger input

 

4. Is there a document in which the internal calculations and correlations are well explained?

many thanks in advance.
Best regards,
Brian

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TPS61088: HT7178 replace recommendation

December 9, 2019, 7:58 am
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Part Number: TPS61088

Hi Team,

Could you suggest a suitable part to replace HT7178?

Thanks,

Will

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BQ24070: BQ24070 alternative with 3.8v System output

December 9, 2019, 8:06 am
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Part Number: BQ24070

Hello,

in our current design we are using BQ24070 which has preset system output 4.4v. In the updated system we need to have 3.8v output. Could you recommend me an alternative IC?

If it has LDO at 3.3v in addition that would be a plus!

Thanks and regards,

Sergey

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BQ40Z80EVM-020: bq40z80EVM is a smart-charger?

December 9, 2019, 7:19 am
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Part Number: BQ40Z80EVM-020

Hi, 

I bought a board bq40z80EVM  expecting that the IC bq40z80 is able to manage the charge of the batteries. I want to use a configuration of 6s Li-Ion.

Is it correct the following sequence to achieve that result?

  • Make a short circuit on the Terminal Block Connections between 6P and 7P on J12.
  • Connect the usb to the PC
  • Load the appropiate configuration for the battery pack
  • Connect a power supply to the PACK+ and PACK– with a voltage > 25,2 (and less than?)
  • Press SYS PRES.

Should I connect on PACK+ and PACK–  to a smart-charger or is it sufficient a normal power supply?

How can I drive the board to charge the batteries by means the "Battery Management Studio"?

Thanks,

Fabrizio.

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TPS62172: Need unencrypted spice model

December 9, 2019, 8:29 am
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Part Number: TPS62172

As in the title. The publicly available model is encrypted and apparently only works with the TINA software. Since I don't really feel like splitting our simulations among more programs, I'm not interested in using that. 

I tried contacting support directly for the model, but they just kick me back to the e2e forum. 

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TPS62130A-Q1: Pre-Bias Operation Scheme of High-Side and Low-Side Switches

December 9, 2019, 9:02 am
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Part Number: TPS62130A-Q1

Dear tech support team,

I would like to apply the PMIC for core voltage regulation.

I would like to understand, how the regulator switches start to operate, when the pre-bias voltage is below the target voltage. 

In the Datasheet (DS) I did not understand clearly how the mechanism is working. For me it is important to know, if  there is some unintended current sourcing by the PMIC due to enabled low-side switches.

Regards,

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LM3488: SYNC SIGNAL FOR LM3488- DUTY CYCLE=50%

December 9, 2019, 10:00 am
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Part Number: LM3488

I have a related question,

i'm dealing with the a similar application (fsw=250kHz) and D=93%.

This SEPIC has to be syncronized with an external clock (50%). The datasheet is saying to give D>93%.

What is the workaround to have the LM3488 syncronized and running correctly at full load (dual rail @ 25mA)

Regards,

Elisa

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BQ40Z80: Internal Cell Balancing at Rest

December 9, 2019, 11:05 am
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Part Number: BQ40Z80

Hello,

Is using the cell balancing at rest feature in an internally balancing design suitable for 2S,3S,4S, and 5S Li-Ion packs?

If so, what are the recommended values for Relax Balance Interval, min RSOC for Balancing, and min Start Balance Delta?

Regards,

Kiel

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TPS7B7701-Q1: OUT limit in normal-mode operation

December 9, 2019, 12:36 pm
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Part Number: TPS7B7701-Q1

According to the TPS7B770x data sheet section 6.3, the recommended maximum normal-mode (regulated) OUT voltage is 20V. Switched-mode operation is recommended up to 35V.

I have an application with Vin = 25V5 - 30V0, Vout = 25V0, where the TPS7B7701 otherwise seems suitable (and is preferred to the TPS7B4253 due to it's current monitoring feature). Reading through the data sheet, I do not see anything that would prevent this part from working with a 25V output voltage, but it's strictly outside the recommended range.

Can you explain if this 20V limit is a "real" limit, or whether the part can reasonably be used to regulate to a 25V output voltage?

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TPS3514: Powering /PSON pin before VDD pin

December 9, 2019, 12:44 pm
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Part Number: TPS3514

Hello E2E support forum, 

i am using TPS3514 on a board. When the board is powered up, /PSON pin is first pulled up to 5V through a 4.7kOhm resistor.  1s later,  VDD pin is powered on to 5V.  

When /PSON is pulled up but before Vdd is up, it seems that /PSON pin has a lower resistance (compared to when Vdd is powered up) and is drawing some current (estimated to be about 0,1mA).   

I am wondering if sequence of voltage is allowed? Will there be potential problems?

Your feedback is much appreciated. Thank you. 

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TPS43060: Over heating

December 9, 2019, 12:45 pm
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Part Number: TPS43060

Hi,

We are using the TPS43060 in an amplifier module to provide a 35V 4A supply. The input voltage range is from about 19Vmin to 29V max. The supply works well until the board starts to heat up under load. A full power after about a minute or so the TPS43060 starts to pulse its output on / off at a regular interval (between the Vin and 35V at few Hz) and afterwards the TPS43060 runs very hot (~80C) with no load on the supply but still seems to work. To fix the problem you need to replace the IC.

The board layout is as per the guidelines and a via is used to connect the pad under the IC to the 0V plane for cooling.

The power supply circuit and PCB layout is below. Note the PCB is 4 layer with the pad connected to the 0V plane.

What is the likely cause of the damage to the IC?

Regards,

Hugh

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BQ34Z100-G1: What chemID should be used to support Li-CFX / MnO2 cell chemistry?

December 9, 2019, 12:58 pm
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Part Number: BQ34Z100-G1

I would like to identify the chemID I should use to support  Li-CFX / MnO2 cell chemistry

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TPS563210A: What is the tolerance on the feedback input current over temperature

December 9, 2019, 2:02 pm
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Part Number: TPS563210A

Hi All

What is the tolerance on the feedback input current over temperature? (-40~85C)

Thanks

Jeff Coletti

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TPS25940: Current Foldback

December 9, 2019, 2:36 pm
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Part Number: TPS25940

Hi team,

Are there any TI eFuses with a current foldback response or something similar?

Thanks,

Michael

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TPS2493EVM-004: TPS2493 Hot Swap Evaluation Board Mosfet start smoking during the load conditions.

December 9, 2019, 1:52 pm
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Part Number: TPS2493EVM-004

I am having trouble with this evaluation board during high load conditions. Or application input is 42V DC and the input source can detect shot if startup current reaching near 32 Amps. To avoid that we would like to use this as an Inrush limiter. Our total output capacitance is 1067 uF and loads current is about 30 Amps. To increase the default sense current limit I changed R15 to 10ohms and R16 to 50ohms and R7 to 2mohms. The board is sufficiently able to limit the inrush but Mosfet starts smoking when load source about 30Amps also I noticed that Mosfet temperature is getting very high above 100C.

The other solution we tried is to use 3 parallel IRFH7085PbF power MOSFET on a new board with 1K resistor on the Gate and we are experiencing the problem as Mosfet in the middle starts getting hot and smoking at load condition.

Second Setup:

Please advise testing anything differently.

Thanks.

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LM5060: Idea Check

December 9, 2019, 3:26 pm
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Part Number: LM5060

Hi TI experts,

We will develop a battery power supply that has 3 x 48V batteries in parallel as power source to provide 48V / 150A to the load (ESCs and BLDC motors).  We want to insert a module between each battery and the load so the module will:
1.  prevent backfeeding from good batteries to bad batteries if batteries become bad such as battery voltage of one or two batteries goes low.
2.  act as an ideal diode OR-ing so power will continuously supply to the load even one or two batteries become bad or removed.
3.  act as a switch controlled by external signal so it will disconnect the battery from the load.
4.  support hot plug batteries, each battery provides less than 2A at the initial stage, 150A at the latest stage controlled by the other subsystems.
After reviewing the LM5060 datasheet (e.g. Figure 39 / 41 on the LM5060 datasheet), it seems:
1.  the ENABLE pin can disconnect the power source from the load,
2.  it supports hot plug (UVLO and OVP), reverse polarity protection is not required
3.  it (as Figure 39 / 41) prevents backfeeding by back to back MOSFETs pairs
We are not sure:
1.  it (as Figure 39 / 41) can act as ideal diodes OR-ing.
2.  it can drive multiple parallel MOSFETs as the continuous current of each module may be 50A.
Could anyone shed some light if LM5060 can meet our design goals.
Regards,
Buta
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LM36011: Jittering Error

December 9, 2019, 3:51 pm
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Part Number: LM36011

We are using the LM36011 to drive LED’s in a flash application.

The driver is in IR mode and according the spec the strobe input is level sensitive.

We supply a 10kHz PWM signal to the Strobe input. One out of 4 or 5 pulses shows a ~1us error. When I change the pulse width or the frequency the error stays ~1us.

 

Do you have suggestions to solve this issue?

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TPS65100: EN open

December 9, 2019, 4:01 pm
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Part Number: TPS65100

Dear all.

Our customer broke a device. (not work boost converter)
As EN was connected to their board outside, EN became open in single board.
It is written in the datasheet with "This pin should be terminated and not be left floating.".

May a device be broken when EN open?
When EN connected to the outside, should I make pull-down?

Regards,
PAN-M

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