SM72445: Buck converter design with SM72445

February 6, 2019, 9:22 am

≫ Next: LM22676: Part fails at startup. Now outputs 8VDC

≪ Previous: BQ25606: Charging battery via USB Port while in DCP mode

Part Number:SM72445

Hi community,

I'm starting to work on a project concerning a power optimizer for solar modules. I checked on the SM72445 and have a few basic questions before I start to work on the design.

Firstly, the SM72445 is controlling a four switch buck boost converter. Is there a possibility to let it controll a simple buck converter?

Secondly, the Evaluationboard was once the Solarmagic power optimizer. What is the advantage of using a buck-boost design? The only thing I can think of is to reduce stringcurrent. But it comes with double the components and more losses compared to a simple buck design. Am I missing something here?

Thirdly, are all the possible adjustments that can be made mentioned in the datasheet of SM72445. Or can other changes be made. For example to force the converter to activate Panelmode under given circumstances.

Fourthly, are other components of the TI-family possible to use for such an application?

Thank you for your help!

Best regards,

Frieder

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LM22676: Part fails at startup. Now outputs 8VDC

February 6, 2019, 9:29 am

≫ Next: LM3410: 3Vin, 20Vout, 250mA. Is this possible?

≪ Previous: SM72445: Buck converter design with SM72445

Part Number:LM22676

Input voltage = 20 volts

Output = 8 volts

Something is happening to the part during operation. It appears to be "shorting", and generates 8 volt output. Can anyone help me figure out a root cause?

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LM3410: 3Vin, 20Vout, 250mA. Is this possible?

February 6, 2019, 9:37 am

≫ Next: Where can I find PF and current harmonic measurements for the PFC reference designs?

≪ Previous: LM22676: Part fails at startup. Now outputs 8VDC

Part Number:LM3410

Hello,

I was trying to go through the datasheet and calculate thermal and boost capabilities of this device, but I've gotten a bit stuck.

Is this device capable of 3V input, 18-20V output, 250mA output?

Thanks,

Nick

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Where can I find PF and current harmonic measurements for the PFC reference designs?

February 6, 2019, 9:43 am

≫ Next: LMZ21701: Output Failure

≪ Previous: LM3410: 3Vin, 20Vout, 250mA. Is this possible?

I am evaluating topology and PFC controllers for a new design.

All the reference design test reports I have reviewed so far fail to test the two most important parameters for a PFC, Power Factor and Current Harmonics!

Is this data available anywhere?

Regards,

Jim Moreau

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LMZ21701: Output Failure

February 6, 2019, 10:24 am

≫ Next: BQ24072T: Quiescent current of BQ24072T if no load and VIN < UVLO

≪ Previous: Where can I find PF and current harmonic measurements for the PFC reference designs?

Part Number:LMZ21701

We are seeing some failures with the LMZ21701 modules where the output seems to have low resistance to ground. Vin = 12V, Vout = 5V, Load<200 mA.

Several other posts on the forum discuss the noise sensitivity of the VOS trace. In this design, the VOS trace is routed from the output cap to the VOS pin on a lower layer, about 20 layers down on the PCB design. Does this approach cause concerns regarding coupling into the via's?

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BQ24072T: Quiescent current of BQ24072T if no load and VIN < UVLO

February 6, 2019, 10:46 am

≫ Next: TPS40200: RC Filter Added to the Current Sensing Network

≪ Previous: LMZ21701: Output Failure

Part Number:BQ24072T

I am evaluating a device to charge a single lipo cell and BQ24072T is my favorite by now. My Question: If no load is connected (i_load approx. 1uA) and there is no source at IN, how much current does the BQ24072T draw from the battery?

I found the definition of IBAT(PDWN) = 6.5uA in the datasheet on page 7. Is this true for all BQ2407x devices or only for the ones with a SYSOFF pin?

Thank you for your help. It is highly appreciated.

Best regards

Patrik

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TPS40200: RC Filter Added to the Current Sensing Network

February 6, 2019, 10:48 am

≫ Next: TPS51200: power sequencing VLDOin and REFIN high while VIN is off

≪ Previous: BQ24072T: Quiescent current of BQ24072T if no load and VIN < UVLO

Part Number:TPS40200

In the datasheet, the overcurrent limit trip point is set by a resistor network between VDD and Isns as shown below:

This is defined by this equation below:

But in some of software designers, an additional RC filter is also added to the VDD pin for power supply filtering, as shown with the 10Ohm and 0.1uF below.

My question is how does the current limit trip point equation change if both RC filters are present (current sense and VDD)? And would Rf2 still be connected between the VDD pin and the Isns pin or would the VDD side be moved before the 10Ohm power supply filter resistor?

I also don't see the cutoff frequency of the RC filter defined for the current limit sensing. What is the equation for the cutoff frequency?

Thanks,

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TPS51200: power sequencing VLDOin and REFIN high while VIN is off

February 6, 2019, 11:00 am

≫ Next: TPSM84624: TPSM84624 on-package small capacitance?

≪ Previous: TPS40200: RC Filter Added to the Current Sensing Network

Part Number:TPS51200

Hello Team,

Quick Question on one of my designs:

Due to power sequencing, VIN is off, VLDOIN and REFIN are on [having voltage inputs (1.2V & 0.6V)]. Will the part be OK? Any reliability impact?

Thanks for your help!

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TPSM84624: TPSM84624 on-package small capacitance?

February 6, 2019, 11:17 am

≫ Next: BQ27542-G1: SOC not changing during first 80% of charge

≪ Previous: TPS51200: power sequencing VLDOin and REFIN high while VIN is off

Part Number:TPSM84624

Hello,

I was wondering if your TPSM84624 and TPS82130/40 have on-package small capacitance for high frequency noise? If not, is that something I should add to the output of those regulators besides just my bulk?

Regards,

David

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BQ27542-G1: SOC not changing during first 80% of charge

February 6, 2019, 11:57 am

≫ Next: BQ35100: Production Programming in Windows

≪ Previous: TPSM84624: TPSM84624 on-package small capacitance?

Part Number:BQ27542-G1

I am doing accuracy testing of my golden image per SLUA684. I get very weird behavior while doing the dynamic load test. After doing the dynamic discharge and letting the unit sit idle for 45 minutes, I begin charging at C/2. Using the Q_integrated calculation, the SOC gets over 80% before the reported SOC changes from 1% (where it was when charging started). What would cause this?

I have attached the BQ27542-G1 logs from BQStudio for both the Registers and Data Memory, as well as logs of the power supply/constant current load used. I am using the production board, that was used to create the golden image. I am using ChemID 210 as provided by the battery supplier and is a valid selection according to the Chemistry ID selection tool results.

/cfs-file/__key/communityserver-discussions-components-files/196/7838.GPC_5F00_report.txt

/cfs-file/__key/communityserver-discussions-components-files/196/Fuel-Gauge-Accuracy.zip

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BQ35100: Production Programming in Windows

February 6, 2019, 12:08 pm

≫ Next: REF5040: VSSOP Package Pin Pitch

≪ Previous: BQ27542-G1: SOC not changing during first 80% of charge

Part Number:BQ35100

Hello,

I need to program the BQ35100 in a production environment with a known good flash image (a bq.fs file).
I see at the end of SLUA801 (Gauge Communication Application Report) there is a Linux C Program.

My production environment will consist of a windows PC and an Aardvark I2C/SPI Debugger.
Is there any sample code out there that I can use on our production line for this type of environment?

Thank you!

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REF5040: VSSOP Package Pin Pitch

February 6, 2019, 12:19 pm

≫ Next: LM117HV: obsolescence: 5962R0722961VZA to 5962R0722962VZA

≪ Previous: BQ35100: Production Programming in Windows

Part Number:REF5040

I am using the REF5040 in a new design. The version in the VSSOP 8-pin package has a pin pitch of 0.65mm according to the datasheet.

In the same new design, I am also using the TMUX6121. The VSSOP 10-pin package pin pitch is 0.5mm according to the datasheet.

I discovered this while creating footprints. Does the TI VSSOP package have different pin pitches for different # of pins?

What is the standard pin pitch for a VSSOP package?

Thanks,

Richard

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LM117HV: obsolescence: 5962R0722961VZA to 5962R0722962VZA

February 6, 2019, 12:27 pm

≫ Next: LM5117EVAL: I would like to reconfigure the eval board to output 5V.

≪ Previous: REF5040: VSSOP Package Pin Pitch

Part Number:LM117HV

Team,

We were using the 5962R0722961VZA (LM117HV) in a design, but that part is now obsolete so we’re looking at using the 5962R0722962VZA instead.

Do both parts use the same die?

If not, what are the differences?

Would you know why the 5962R0722961VZA went obsolete?

↧

LM5117EVAL: I would like to reconfigure the eval board to output 5V.

February 6, 2019, 1:53 pm

≫ Next: UCC2895: Simplis UCC2895

≪ Previous: LM117HV: obsolescence: 5962R0722961VZA to 5962R0722962VZA

Part Number:LM5117EVAL

Hello,

I have received the evaluation board p/n: LM5117EVAL and would like to set it up to output 5V. I have calcualted the feedback resistors should be 357 ohms for R_FB1 (R16) & R_FB2 should be 1870 Ohms (R17).

I wanted to ask if there is anything else I am missing or if I should not use this board for that voltage output? I did the web bench designed and it does not list chip given my input parameters of 8V < Vin < 56V with nominal voltage been 12V. We expect a current peak at 10A for about 30 seconds and nominal current would be about 3A.

Thank for the help,

↧

UCC2895: Simplis UCC2895

February 6, 2019, 3:33 pm

≫ Next: TPS65400: We cannot get the USB2ANY pod to access the TPS65400 EVM module.

≪ Previous: LM5117EVAL: I would like to reconfigure the eval board to output 5V.

Part Number:UCC2895

Is a simplis model available for the UCC2895

↧

TPS65400: We cannot get the USB2ANY pod to access the TPS65400 EVM module.

February 6, 2019, 3:36 pm

≫ Next: LMG1020EVM-006: Resistors at GaN

≪ Previous: UCC2895: Simplis UCC2895

Part Number:TPS65400

We cannot get the USB2ANY pod to access the TPS65400 EVM module.

After many attempts of trying to backdate the firmware to (1.19.0.0), still not working.

We visited these forums and have tried about everything possible, even renaming the (1.19.0.0) to 2.8.2.0.txt file used for the update firmware.

Our USB2ANY Explorer does not let us select the file to load for firmware.

The PI commander did work once, in the very beginning. But USB2ANY was ran and dictated we upgrade the firmware to 2.8.2.0.

Since then, we cannot get the pod to communicate to the TPS65400 EVM. We would greatly appreciate any help.

↧

LMG1020EVM-006: Resistors at GaN

February 6, 2019, 4:47 pm

≫ Next: LM3553: LM3553 Evaluation board GUI

≪ Previous: TPS65400: We cannot get the USB2ANY pod to access the TPS65400 EVM module.

Part Number:LMG1020EVM-006

Hi,

Could you please give me your advice? LMG1020EVM-006 has resistors (R5,6,7 and 8). What is purpose for them? I would like to evaluate optical -device with LMG1020EVM-006. Can I remove the resistors?