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bq51050 disable charging & use of RECT for system load

October 4, 2016, 6:26 am
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I am using the bq51050B and have seen the reference design. I just had two questions:

  1. Disable Charging

Is my understanding correct that I can choose to pull up/down TS/CTRL to disable charging? My plan is keep either the 10kOhm or thermistor, but have a FET to allow a micro-controller to disable charging if needed.

2. RECT to power system load

I noticed on the evaluation board that RECT output (typ. 5V) is used to power the charging LED. is there a spec to the current allowed to be drawn by this pin - didn't see it in the datasheet. My system load can be low .e.g a few mA. Sometimes higher 300mA. 

Many thanks,

James

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BQ51013B Audio noise

October 4, 2016, 8:58 pm
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Hi, 

I'm using the BQ51013B for new design,

but I found the Audio noise near the IC and CS/CD capacitor, and it happens on the BQ51013B EVM too.

is there any way to reduce the audio noise? 

Stanley

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BQ51221 pin CM_ILIM

October 5, 2016, 2:39 am
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I observed with our Qi Transmitter and the BQ51221 on the Qi Receiver side a much more stable charging process

if I pull-down the CM_ILIM pin on the BQ51221 with the internal pull-down of the BQ51221. Much more stable charging

process means that the charging doesn't stop in an unexpected manner (or with other words Qi Transmitter keeps

connection with BQ51221). Now my questions.

 

  • In the BQ51221 datasheet it is mentioned that the charger IC which is connected to the BQ51221 output

    needs a VIN-DPM feature. In our case we have the charger IC BQ24166 which has a on Pin 1 the input

    named VDPM. I assume that the BQ24166 VDPM input fulfills the needed VIN-DPM feature which is

    mentioned in the BQ51221 datasheet?

  • The BQ51221 output is adjusted in our case to 5 Volt. The voltage divider of the BQ24166 VDPM input

    which is connected to the BQ51221 5Volt output is dimensioned in a way that the 1.2Volt threshold of the

    VDPM input is reached if the BQ51221 output voltage decreases from 5Volt down to 4.4Volt. Now my

    question: Is there any further information regarding the needed VIN-DPM feature and how to dimension

    the voltage divider on the VDPM input of the BQ24166 in the right way? I’m asking this to avoid that the

    output of the BQ51221 will collapse if the communication current limit is enabled.

  • Will the BQ51221 EMC behavior (radiated emission and immunity) change if the communication current

    limit is enabled compared to the case of disabled communication current limit?  

 

I would appreciate it to get feedback.         

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BQ51221 Heat up when using

October 5, 2016, 4:53 am
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Hi

I have a problem with BQ51221 on my board, it is going to be warry worm, and do not give much power out.

The construction is similar to application.

I have tried with different coil and it do not change the heating. 

sluuax6b.(Please visit the site to view this file)

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bq501210 Enquiry

October 7, 2016, 2:13 am
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Hi TI Experts,

> If I want to implement this module to our product, is this module is hardware base or firmware base? Hardware base means you can just adjust the resistor values      to change mode or else,   meanwhile if firmware base you need to write your own coding to make it work.

   I saw there is an I2C and JTAG port. 

> What is SNOOZE function? If I remove this circuit, is it will affect the circuit function?

> What is PWR_UP function? If I remove this circuit, and replace it will Pull up resistor, what is the recommended value?

> If I want to change the coil to WE-WPCC Wireless Power Array, is it compatible with this circuit?

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BQ51013A gets way too hot under moderate load

October 7, 2016, 7:01 am
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We're using a BQ51013 to charge a lithium battery.  At 500mA coming out of the BQ51, we measured the chip at over 140F.  The BQ51 is on a small device and it's heat soaking everything, including the battery.  This has been causing batteries to bulge.

Dropping the charge current down to 250mA reduces the BQ51013's temperature to 125F, but that's still too hot for the battery.

What can be done to reduce the BQ51013 temperature?  It's heating up our entire device.

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Design modification for TIDA-00318

October 14, 2016, 11:47 am
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Hello,

I want to use the TIDA-00318 reference design in my new project, but the coil I have to use is WR121210-27M8-ID (8.32µH Wireless Charging Coil Receiver 950 mOhm 0.472" Dia x 0.013" H (12.00mm x 0.32mm)). 

How can I modify the reference design to accommodate for this coil ? Can I modify it to work with other coils ? I need to know the components value difference so I can use this design with  BQ51003 + BQ25100 combo to charge my coin cell battery(ML-2020/H1CN). 

Please help me find a solution. Thank you very much.

Best regards,

Summaiya Siddiqui

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"End Power Transfer Packet" of BQ51013

October 16, 2016, 6:09 pm
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Dear, All

A customer is evaluated using the BQ51013BEVM-764.
To the customer in the evaluation, was observed "0x5B" and "0x9B" as "End Power Transfer Packet" of BQ51013.
However, in the item of "8.3.7 End Power Transfer Packet (WPC Header 0x02)" in the "WPC 1.1 Compatible Fully Integrated Wireless Power Receiver IC.pd", this packets have not been described.
Please tell us about the two items below.
- What is the meaning of that packet?
- EVM board a condition that output that two packets?

Thanks, Masami M.

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Loosely coupled coils

October 17, 2016, 3:39 am
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Hi!

Wireless charging has giving me troubles lately. For my device I need to find solution for wireless charging of small LiIon battery. Supply/charging voltage is 5V and charging current is max 500mA.

Problem is in Rx coil. It has to be small to fit the device. Square coils can be up to 15x20mm, and round coils up to 10mm OD. Charging distance must be 5mm or more (there is 2mm wall thickness for charger, and another 2-3mm wall thickness of the device itself). Tx coil can be of any size as the dimensions of the charging station is not critical.

I have contacted various Asian companies that sell various Rx/Tx coils, but none seems to have an answer to my problem. I'm guessing because they are mostly re-sellers.

If anyone can appoint me in the right direction how to begin to solve this problem, I would greatly appreciate.

Creating my own pcb is also one of the possibility, but I would prefer standard solution.

Thank you in advance!

Best regards,

Sasa

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How to change the comm capacitor if I want to use a small coil?

October 17, 2016, 9:15 am
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Dear TIers:

I want to build a wireless charging circuit used for the wearable devices? Can I change the change the coil to 10mm? How can I change comm capacitor without affecting the communication between Tx and Rx? Because I use Bq40012evm for my transmitter now, how can I solve the coupling issue? Thank you.

Best regards,

Yang Fan

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Sending customer data through Wireless charging coils?

October 17, 2016, 9:21 am
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Hi,

Working on a project using Wireless Power for battery charging, I need to send one data byte (customer information) : I haven't find IC's able to do this!!

If I understand WPC1.2, it'll possible to exchange customer data between Rx and Tx, , but not at this time WPC 1.1 and 1.0


Could you confirm if I'm right or Not ?

Is there a way to do this, I've just a byte to send from Tx to Rx.

Thanks

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BQ51050B charging voltage problem

October 17, 2016, 9:54 am
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Hi,

We have been working on a smartwatch that uses wireless charging. At the moment our design includes BQ51050B, however we have been experiencing some problems.

One I am trying to solve at the moment is related to the charging voltage. For some reason the charging voltage never goes over 4.03V and that causes the battery to never fully charge. I checked Vrect and it is around 5.1V which seems as good value (from datasheet). Also it seems that the charging current is lower than it should be.

Have you ever experienced something similar? What could be a potential issue?

I have attached our schematic. I need to mention that 10k pulldown on TS/CTRL is missing in the schematic, however it is present on the board.

Thank you.

Regards,
/Erik


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BQ51222 WPC v1.2 Receiver: how to select R.FOD and R.1

October 18, 2016, 5:44 am
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Hi,

I can't find instructions how to selected R.FOD and R.1 for the BQ51222 WPC v1.2 Receiver.

I found the sluc577a for the BQ51003 but it so far did not help me because it quits with somthing like "FOD Calibration does not function anymore".

- Is this tool also applicable for the BQ51222?

- if yes, how can I get it to execute? (My OS is win 7, 64 bit)

I also found some reference design for the BQ51003. Can I use the R.FOD and R.1 values for the BQ51222 as well?

regards,

Thomas

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WPC Charger Range Issue

October 18, 2016, 3:03 pm
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Hello,

I've created a design using a BQ500212 (transmitter) and BQ51050B (receiver) to charge a Li-Po battery. I'm very limited on space, so I've gone with a 12mm coil for the Rx (Abracon AWCCA-12R12H11-C01-B), and I've tested multiple Wurth Tx coils (760308101103/4/5), as well as a TDK WT151512-22F2-ID Tx coil. I have ordered the matching TDK WR121210-27M8-ID Rx coil to do more testing, but it has very similar parameters to the Abracon Rx coil.

My problem is that my charging distance is no greater than 2.5mm. Any greater than this and charging won't initialize. I can get it to start charging and then move the coils to 3-3.5mm and charging will continue, but I need it to be able to start charging at 5mm. I've looked at my capacitor selections per WPC and the datasheets, and everything seems to equate correctly. Schematics below. Any help is greatly appreciated.

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bq500511 & bq50002

October 18, 2016, 6:52 pm
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I have question.

What is the difference between A & Non A revision?

Best Regard,BANE

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Wireless charging of 4.2V Li Ion battery using BQ51051B and BQ25120 PMIC

October 20, 2016, 7:04 am
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Hi,

I have a wireless receiver using BQ51051B for charging a 300/200mAh Li Po battery and a wireless coil of 15.6uH (Ls') (measured with the help of LCR ammeter in a final arrangement). I am sharing the schematics we have used in our setup. The transmitter being used is BQ500410 EVM from TI. The final circuit can draw up to a maximum of 120mA while operation. The coil is getting detected as I can hear the buzzer of TX EVM beep every time I place the receiver coil on top. Even the LED glows on and off which is an indication of power transfer. The battery gets drained instead of charging. Please clarify the following for me and help me identify the mistake I am doing in this.

  • We want wired and wireless charging in our setup. When there is no valid input to AD line, the wireless charger should be working right (capable of charging battery)?
  • How can I find if the battery is charging or not?
  • I tried the custom coil with BQ51050B EVM and it works without changing the tuning circuit, so can I rule out the possibility of mismatch in tuning from custom board? (I even tried replacing the capacitors in custom board, no luck. When I measure voltage at AC1, AC2 of RX, I can see 3.0 -3.3V, which I presume is more than enough to start working
  • When I probe RECT line of RX at C33 in my schematic, I get voltages varying from 4.3 to 5.02V, but nothing higher than this? Can I increase the RECT voltage seen by the RX?
  • As per battery specifications shared by our battery manufacturer, safe charging limit is 0.2C and when computing using equation 1, i am getting a charging current limit of 80mA for 3.83K. Is this value ok for charging current, as our initial assumption was charging current is not enough as the load keeps on draining something like 60mA constantly. To verify the same, we changed target board configuration and kept it in a low power mode consuming nearly around 6mA, still battery is draining at a slower rate
  • How can I sniff the packets transferred between receiver and transmitter?
  • When I probe using scope at AC1 line of TX EVM, I can see the digital ping at 175KHz, but at RX end, the voltage level is too small, but frequency remains somewhat same.

Please help me with this and do guide me with insights which can get this setup working.

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bq501210 Power mode

October 21, 2016, 12:55 am
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Hi,

My Question is : if there is a block diagram that shows the power mode of bq501210. I need to know for example when the SNOOZE pin switches to a High or Low.

Bq501210 can turn off the 3v3 voltage Regulator( via EN pin), in this case what is the Voltage Source of Bq501210, V_IN pin or PWR_UP pin?

Thank you very much.

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BQ51222 Problem with output voltage

October 24, 2016, 1:18 am
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Hi,


I made wireless charger based on new BQ51222, but its same like BQ51221. I want to support only WPC (Qi), not need PMA. Here is schematic, problem is I have voltage on rectifier RECT output about 6.2V, but never voltage on OUT pins of IC, so what can be problem. Voltage on NTC is about 0.55V, voltage on divider from RECT is similar about 0.5V but no output voltage.


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Irregular diagram of BQ51050b receiver standby current vs battery voltage

October 25, 2016, 10:03 am
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I'm designing a portable battery-powered device with BQ51050b receiver to charge it. The application requires that standby current of BQ51050b to be no more than ten uA at max charged battery. And less - if battery is discharged. The datasheet for the IC tells us that "Quiescent current at the BAT when wireless power is Q disabled (Standby) to be 12 uA @ VBAT = 4.2V". That's seems to be fine, because I expect the standby current to go down as battery discharges. But, in fact I get an opposite behavior.

My prototype (with typical application schematics and parts) draws about 10uA from a fully charged 4.2V battery. If we make battery voltage less, the quiescent suddenly current jumps up to 28uA at 3.65V battery level. It goes less with less Vbat then. But it still 20uA @ 3.3V and 15uA at 3.0V.

I'm wondering, is there any way to fight this issue?

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Where are the gerber files for the BQ501210EVM-756 available for download as referenced in the Ti application note bq501210EVM slvuao6 application document?

October 26, 2016, 12:38 pm
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Where are the Gerber files for the BQ501210EVM-756 available for download as referenced in the Ti application note bq501210EVM slvuao6 application document?  Please email me directions on how to access them.  My email address is Hauiki.Research@gmail.com

Kind Regards

John J. Lord

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