Quantcast
Channel: Power management forum - Recent Threads
Viewing all 35901 articles
Browse latest View live
↧

BQ27421-G1: Issue in modifying BATLOWEN bit of OpConfig register

October 22, 2018, 6:42 am
$
0
0

Part Number:BQ27421-G1

Hi,

I'm using BQ27421-G1A fuel gauge in our design. I was able to program the basic fuel gauge registers (Design Capacity, Design Energy, Termination Voltage and Taper Rate) through microcontroller over I2C. 

I wanted to use Battery Low Function, for which I need to modify BATLOWEN bit of OpConfig register. 

I'm always getting error when I want to read OpConfig register. I followed the same procedure which used for updating basic registers.

Can you help me how can I modify this register by providing its base address & offset. Point out if I'm missing anything.

Thanks & Regards

Vidyasagar

↧
Search

BQ27510EVM: Use of EV2300 with BQ27510EVM

October 22, 2018, 7:13 am
$
0
0

Part Number:BQ27510EVM

What is the use of Ev2300 Communications transceiver with the Bq27510.  I just need to communicate the Cell voltage, Cell SOC . Will I be able to do this without the EV2300 and use arduino instead?

↧
↧

WEBENCH® Tools/LM3478: LM3478 and the CSD16321Q5

October 22, 2018, 7:26 am
$
0
0

Part Number:LM3478

Tool/software: WEBENCH® Design Tools

I used the Workbench designer to come up with a 3.7-4.2V to a 12V voltage converter.  The design uses the LM3478 voltage regulator along with the CSD16321Q5 Mosfet.

I made a circuit board following the schematic.  With the Mosfet in the circuit the input voltage is getting pulled down to 0.28 volts.

I'm not sure how to attach the schematic.

↧

AFE requirement

October 22, 2018, 7:28 am
$
0
0

We want to develop off-road motor's battery BMS.
The average current is 30A, but the peak current is 200A(last 3~5 sec).
That is, need to ensure D_FET is on when the discharge current is 200A(last 3~5 sec).
Also, the required cell number is 13S.
Which AFE satisfy such requirement?

Thanks

↧

LM25085: lm25085 regulation

October 22, 2018, 7:30 am
$
0
0

Part Number:LM25085

Hello,

I have a problem about output voltage regulation with the COT LM25085. It's about line regulation. When I exceed 14 V on Vin, my voltage ouput regulation (8V2) is bad for the same load. See different pictures attached. The problem is probably due to parasitic inductances but i'm not sure. I decided to add a resistor of 10 ohm in series with the pin which control the gate of the LM28085 and PFET gate. Now it works, I can exceed 16V. So it seems that the commutation was to fast and i think that there were spikes to high on my FB ripple (exceeding 1V575 as it is mentionned into the datasheet), in that case the LM25085 stop to regulate until the FB ripple go down to 1V25 something like this... My interpretation may be wrong, please tell me if iit's wrong.

I don't want to let my 10 Ohm resistors in series with the PFET gate. My layout doesn't allow me to do this. So i m asking if i can take a diode which would be slower ? Do you think it could help me ?

For information, the ripple injection configuration that i m using is the one with the RC integrator and the bypass capacitor.

Here are ripple @ different VIN :

15V

13V

14V

Thank you very much,

Have a nice day ! :)

↧
↧

TPS659037: TPS6590379ZWSR difference between dowloaded symbol ans schematics

October 22, 2018, 7:31 am
$
0
0

Part Number:TPS659037

Hi,

I have downloaded the TPS659037 symbol from TIs homepage and comparing it with the ARM MPU AM572X Industrial EVM I have found tthe following differences:

K4 marked as NC in the downloaded symbol is used as LDO5_OUT in the EVB

K5 marked as NC in the downloaded symbol is used as LDO8_OUT in the EVB

L4 marked as NC in the downloaded symbol is used as LDO6_OUT  in the EVB

Are those pins NCV or used in TPS6590379ZWSR?

Johan Bendz

↧

TPS61252: bode plot data

October 22, 2018, 7:43 am
$
0
0

Part Number:TPS61252

Hi Team,

May i know if the bode plot data for TPS61252 is available? The end customer has  question regarding stability and phase margin.  Can you share the characterization data on this? 

And also can you also comment the impact of the additional filter network as shown below to the phase margin and gain?

Best regards,

Andy Chu

↧

TPS84250: LMZ35003

October 22, 2018, 7:57 am
$
0
0

Part Number:TPS84250

Hi,

Theses are two devices that seem identical: TPS84250& LMZ35003

Both these devices have two ordering options each:

TPS84250RKGR

TPS84250RKGT

LMZ35003RKGR

LMZ35003RKGT

The datasheets do not do a good job of defining the gross differences between the two parts (TPS vs LMZ) nor the ordering options (KGR vs KGT) differences

Please explain!

Thanks!  

↧
Search

LM2642: 12V 33A backup output power supply for PC mother board

October 22, 2018, 8:33 am
$
0
0

Part Number:LM2642

Hi there,

I want to add a 12V backup power supply for my PC mother board. My target output power is 12V 33A, input from a suitable battery from 10-14.4V.

Because there's no multi-phase buck-boost controller I think, so my proposal is to use cascaded boost and buck controller to derive a 12V output from 10-14.4V input. Do you have better recommendations?

Right now, I am considering LM2642 for the multi-phase buck controller (boost controller is not selected yet), however, space(inductor size and input capacitor size) is not too critical in my application. Do you really recommend multi-phase converter? Or just single phase is OK? My output current is "only" 33A, not crazy values like 56A or so...

Thank you.

↧
↧

BQ27441-G1: BQ27441 --- I2C command waiting time

October 22, 2018, 8:59 am
$
0
0

Part Number:BQ27441-G1

"For read-write standard command, a minimum of 2 seconds is required to get the result updated. For read-only standard commands, there is no waiting time required, but the host must not issue any standard command more than two times per second. Otherwise, the gauge could result in a reset issue due to the expiration of the watchdog timer. "

1. Looks Vague  -- Should These Statements be  Taken  "Seriously"? 2 Seconds Sounds Big Value @ f=100KHz

2. Cant Internal Insight (Architectural Diagrams, State Diagrams be shown e.g. Like bq27441- Figure 2-1. Power Mode Diagram of Technical Reference Manual) for Communication Engine instead of Raising All these Confusing Questions Below (One Proper Diagram Would Have Clarified Many Doubts)
https://e2e.ti.com/support/power-management/f/196/t/538858?TI-BQ27421-gauge-I2C-command-waiting-time------https://e2e.ti.com/support/power-management/f/196/p/538858/2033032?pi317195=1-----https://www.avrfreaks.net/forum/bq27441-g1-battery-fuel-gauge-i2c-shenanigans-----

3. Where Can I Find More Insightful Information on I2C Engine in BQ27441-IC (which can Clarify Doubts raised by Half-Half Information provided in Datasheets, Reference Manuals...)

↧

TPS3808: TPS3808

October 22, 2018, 9:00 am
$
0
0

Part Number:TPS3808

Hi,

Would you answer these questions:

- Is the part CMOS or bipolar

- Have you done electrical latch up testing

- Do you have any radiation test data on the part?

thanks

Munir

↧

LM5069: Tolerance of Current Limit

October 22, 2018, 9:01 am
$
0
0

Part Number:LM5069

The current limit for the LM5069 seems to be wide once set based on a maximum load. It appears that I have no tight control of that based on the internal Vcl threshold votlage range of 48.5mV to 61.5mV.

I set my maximum load to 20A but the current limit maximum can be 30.8A. Is there a way to tighten this limit closer to the max load? I did use the design calculator spreadsheet and then used my own calculations to modifiy the tolerances of the current sense resistor as well as the optional resistor divider.

That did not seem to help. I want to confirm that the limiting factor is the Vcl threshold voltage range.

Thank you

↧

TPS54478: TPS54478 LATCHUP

October 22, 2018, 9:01 am
$
0
0

Part Number:TPS54478

Hi,

Would you answer these questions:

- Is the part CMOS or bipolar

- Have you done electrical latch up testing

- Do you have any radiation test data on the part?

thanks

Munir

↧
↧

BQ25050: Forced termination

October 22, 2018, 8:48 am
$
0
0

Part Number:BQ25050

Hi everyone, 

We are using a BQ25050 charger in our product. It works great, but we are adding a testing step in our production where we want to measure the system power draw after assembly. The system consumes in the range of 100uA, so since the battery currents are at a minimum 95mA with 7% current measurement accuracy the system power consumption will drown in the battery charging current. What we are trying to do in order to solve that problem is get the BQ25050 to turn off the Qbat FET and regulate 4.2V on the OUT pin. According to table 2 in the datasheet of the BQ25050 you can send 1 pulse and it should terminate the charging. I am measuring the current on the USB port side and can see that there is a period about 30ms long after the force termination pulse has been sent where it seems to terminate the charging, but it then starts again. If I first send the Force on command (3 pulses) and then the force termination command nothing happens, so it would seem that the 30ms of no charge is indeed the force termination triggering. 

This is the system state:

Battery voltage is around 3.9V

OUT is connected to the system.

TS is connected to a 47k NTC resistor

The ctrl pulses are high for 0.5ms. 

CHG is pulled high through a MCU GPIO

IMON is connected through a 1k resistor to ground

What am I doing wrong ?  Why does the charge cycle restart after around 30ms ?

↧

BQ35100: ACCUMULATOR MODE

October 22, 2018, 9:27 am
$
0
0

Part Number:BQ35100

Hi TI team,

Now, I am studying to use BQ35100 in ACC mode. I would like to have more explanation about this mode and confirm my understanding of datasheet.

In our application, most of the time our system is in low power and our profile current presents a very quick active current around a few 1-100ms and not exceed 100mA.

Datasheet say: "In this mode, the bq35100 device measures and updates cell voltage, cell temperature, and load current every 1 s and begins accumulating after GAUGE_START is received.[...]"

That why I am seeking that ACC mode could not be able measureour profile current because sampling of this mode is every 1s. Could ACC mode be able to monitor capacity with type of current profile (when current go to high during a few ms)?

Regards,

Alexis.

↧
Search

BQ25708: 1S Cell application, BQ25708 stop charger Battery when set CV voltage exceed 4.288V , set lower than 4.288V, the charger is normal

October 22, 2018, 9:56 am
$
0
0

Part Number:BQ25708

Hello

1S Cell application, BQ25708 stop charger Battery when set CV voltage exceed 4.288V , set lower than 4.288V, the charger is normal

so what probably happens ?

↧

LM5160: In Fly-buck topology application

October 22, 2018, 10:22 am
$
0
0

Part Number:LM5160

Hi,

    I have fly-buck topology application.

    Vin=4.5-65V, Vo=12V, Io=2A

    I find LM5160's datasheet Io=1.5A, but website is 2A, which one is correct?

    Is there any suggest IC in fly-buck application?

thanks,

↧
↧

TPS22922: Device Failures

October 22, 2018, 10:46 am
$
0
0

Part Number:TPS22922

I am currently using the TPS22922 load switch in a very simple application where it controls the power to a small altimeter. The input voltage to the load switch is between 2-3V (Coin cell). Input capacitance is >> than the output capacitance. The on signal is controlled by a micro.

I have observed a failure on multiple devices where there is a residual voltage (~1V) at the output when the load switch is off (ON is low). This is causing a significant amount of current to be drawn across the 65ohm resistor in the active discharge circuit. The output voltage appears to be leaking through the device through VIN. When I reduce the voltage at VIN, VOUT follows lower. So the delta is typically around 2V.

Any thoughts on what would be causing this leakage? Is it the body diode getting damage?

Note that I have confirmed there is no leakage happening through the altimeter itself. 

↧

TPS62740: Maximum source impedance on the EN pin

October 22, 2018, 1:48 pm
$
0
0

Part Number:TPS62740

Hello,

Could you please advise what is the maximum source impedance permissible on the Enable pin for the TPS62740?  I would like to use a 10 M pull up resistor so I can minimize the leakage current when I put the device in ship mode.  A 10 M resistance with a 3.6V battery would have a 360nA leakage.

From the datasheet, page 5 shows the input bias current is 25nA.  So, with a 10 M pull up that would cause 0.25V drop which would satisfy the VIH for a battery voltage of at least 1.35V.

Is there anything else I need to consider with regard to the impedance of this pull up?

Thank you,

Steve

↧

BQ24610: Simulated load for functional testing of the charging circuit

October 22, 2018, 2:04 pm
$
0
0

Part Number:BQ24610

I need to perform a functional test on the attached battery charging circuit. The battery to be charged is 7.2V, 9.0Ah, 64.8Wh, Li-ion rechargeable. Originally, my customer indicated a 5.1 ohm, 15W resistor would be an acceptable simulation of the battery, however he apparently neglected to account for the battery detection scheme employed by the BQ24610. After I pointed this out, he directed me to simulated the battery load. Should I be able to simulate the battery, and thus test the charging circuit, using something like a NI PXI-4130 SMU, http://www.ni.com/en-us/support/model.pxi-4130.html? Any other recommendations?

Following is an outline of the test procedure employed:

1. Connect an electrical simulation of the Smart Battery at the Power Board battery connector J2.7 (V_BATT) with respect to GND.

2. Apply a 10K resistor across Power Board R27 (NETJ2_5 to GND).

REFERENCE: This will trick the charger into thinking it’s at a constant 25 deg C. and will allow the charger circuit to work.

3. Apply External Power (15.0VDC ±5%) current limited to 2.0ADC with respect to GND.

4. Measure the voltage at the Power Board battery connector J2.7 (V_BATT) with respect to GND. Record the result.

REFERENCE- Battery charger testing does not include charge-rate, or other design verification testing – only checking the charger responds to external power and switches voltage to the battery terminals when voltage is low.

5. Observe the digital state on net ACDRV. Record the result.

6. Measure the voltage on the signal generated by net BATDRV_N (J3.20) with respect to GND. Record the result.

7. Observe the digital state on CHARGING_N. Record the result.

8. Observe the digital state on CHG_COMP_N. Record the result.

9. Observe the digital state on PWR_GOOD_N. Record the result.

10. Observe the digital state on CHARGE_ENABLE. Record the result.

11. Observe the digital state on LOW_CHARGING_LEVEL. Record the result.

12. Disconnect the previous resistor from Power Board R27 (NETJ2_5 to GND) and apply resistor of 3.02k±5%, ≥1/16W Ohm across Power Board R27 (NETJ2_5 to GND).

REFERENCE: This will trick the charger into thinking it is above its high temperature threshold.

REFERENCE: Customer requirement is to only test at valid temperature and one invalid temperature. (“only validate the function once”)

13. Measure the voltage at the Power Board battery connector J2.7 (net V_BATT) with respect to GND. Record the result.

14. Disconnect the previous resistor from Power Board R27 (NETJ2_5 to GND).

↧
Viewing all 35901 articles
Browse latest View live
Search
<script src="https://jsc.adskeeper.com/r/s/rssing.com.1596347.js" async> </script>