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

BQ27531-G1: Voltage range for reporting 100% of remaining cap

March 28, 2019, 8:09 am
$
0
0

Part Number:BQ27531-G1

Hi,

I would like to know the cell voltage range for report 100% remain cap. GG file has Charging voltage and Taper Voltage.

If the Charging voltage is 4200mV and Taper voltage is 100mV,  will bq27531 report 100% remaing cap when cell voltage is 4100mV ~ 4200mV?

And if user use bq27531-G1 + host control mode of bq24193 solution,  will bq27531 stop charging at 4100mV during charging and will charge once cell voltage decrease under 4100mV during self-discharging?

Regards,
Nagata.

↧
Search

TPS53317: why the device TPS53317 can be used as DDR terminator,

March 28, 2019, 8:14 am
$
0
0

Part Number:TPS53317

Hi team,

why the device TPS53317 can be used as DDR terminator, How the device achieve sink current ability? Why other buck converter cannot be used here?

Thanks.

↧
↧

TPS543B20: Max duty cycle vs frequency chart

March 28, 2019, 8:20 am
↧

BQ40Z50-R1: BQ40Z50-R1

March 28, 2019, 8:33 am
$
0
0

Part Number:BQ40Z50-R1

Hi ,

How do I detect the System present on the fuel gauge . Which register should I be monitoring? I am currently monitoring PRES register and it is always set to high . I tried to Connect the PIN to ground and apply a load but the flag is never cleared . Please let me know if I am doing something wrong .

Thanks,

Naveesh

↧

LM5116: LM5116 overcurrent protection and short circuit problem for help

March 28, 2019, 8:33 am
$
0
0

Part Number:LM5116

Hello, TI's expert:

        I am using LM5116MHX to make an 18-60v input and three-way output BUCK power supply.The output parameters are 5V 4A, 12V 3A, 12V 3A.Under different input voltages, the functions of output overcurrent protection and short circuit protection were tested. It was found that under certain input voltages, the output current during short circuit could only be limited to the set overcurrent point without burping protection. The BUCK inductance would have saturation risk.The minimum pin voltage of LM5116MHX UVLO was measured with an oscilloscope and the minimum value was found to be greater than 200mV. It was suspected that there was something wrong with the RAMP compensation circuit. As described in page 16-17 of the data table, the RAMP capacitance was adjusted by using WEBENCH POWER DESIGNER and a resistance was added between VCC and RAMP to increase RAMP compensation.The following figure shows the UVLO and output current waveforms I measured at different input voltages.Attached are the schematic diagram and PCB. Could you help me analyze this problem in detail?Looking forward to your early reply, thank you very much!

(1) 30V input 5V output short circuit, UVLO and output current waveform

(2)30V input 5V output short circuit, boot instant UVLO and output current waveform


(3)45V input 5V output short circuit, UVLO and output current waveform


(4)58V input 5V output short circuit, UVLO and output current waveform


(5)Schematic diagram

(Please visit the site to view this file)

↧
↧

LM337: LM337 output ripple problem

March 28, 2019, 8:34 am
$
0
0

Part Number:LM337

I am using LM337T to regulate -15v to -10v. So far I am able to see -10v. But I am also having a ripple at the output. It is a triangular shaped 40mVpp signal at around 8-10kHz. My input has 10mV ripple. LM337T was supposed to reduce it but it amplifies the ripple by a factor of 4. I've followed the schematics and layout that is in this link: . So do you have any suggestion or anything that we need to double check? I am attaching our schematics. I have everything on my board that shown in the schematic except the protection diode. (D5 in my schematics).

↧

LM2676: LM2676 Thermal Information

March 28, 2019, 8:55 am
$
0
0

Part Number:LM2676

Hi E2E,

Good day!

Do you have the thermal resistance data for LM2676? The datasheet has table on section 6.4 Thermal Information. However, it appears to be referencing to LM2678. Below are the images for both LM2676 and LM2678 Thermal Information.

Thank you in advance for the help.

Best regards,

Franz

↧

BQ34Z100-G1: how to turn on the SOH updates

March 28, 2019, 8:56 am
$
0
0

Part Number:BQ34Z100-G1

hi,

On page 13 of bq34z100-g1 technical reference  there is described, that  FlagsB():0x12/0x13 SOH flag is active, when SOH:StateOfHealth()calculationis active. Does this mean, that it is active at the moment i. g. the algorithm upadtes the value of SOC right now, when the flag is set, or the flag is set, when SOH updates enabled generally(i.g. if flag not set, SOH is never updated)?

If the second option is correct, can you, please, explain how to turn on SOH updates? 

thanks a lot in advance

KR

Vincenzo

↧
Search

BQ34Z100-G1: one cell Li-on. Do you have some recommend devices of Gas gauge and protection?

March 28, 2019, 9:00 am
$
0
0

Part Number:BQ34Z100-G1

Hi team,

my customer wants to design video doorbell, the battery is one cell Li-on. Do you have some recommend devices of Gas gauge and protection? Thanks.

↧
↧

WEBENCH® Tools/TPS61256: 150mA output the output voltage drops?

March 28, 2019, 9:00 am
$
0
0

Part Number:TPS61256

Tool/software: WEBENCH® Design Tools

Hello,

My customer was considering using the TPS61256 component.

He also used WEBENCH for the design.  (Attached the Webecnh Report). He tried to simulate the circuit starting from the model provided by TI, both with PSpice and with TINA, but having reached a load of about 150mA the output voltage collapses.

Is customer mistaking something? Any comments?(Please visit the site to view this file)

↧

TPS61081: TPS61081's input and output voltage was incorrectted

March 28, 2019, 9:05 am
$
0
0

Part Number:TPS61081

Hello

input voltage is 3.3V, when add 3.3V connect to VDD3V3(PIN 2), TPS61081 ouput voltage should be 7.65V normally, but actually output voltage just 1.4V, and strange thing is voltage on VDD3V3(PIN2) also change to 1.65V. when I disconnect input and VDD3V3(PIN2), the input voltage is 3.3V,this input is no problem.

Since this device have overcurrent and short circuit protection,this phenomenon don't like caused by overload and output short

↧

BQ76940: BQ76940 TSX Iissue

March 28, 2019, 9:17 am
$
0
0

Part Number:BQ76940

Dear  All:

       there are  no 10K resistor  pull down with TS2 to VC5X and  TS3 to VC10X in my MP products. Also about 1%  of the 2000 products ，X-ready indicate “1”, I can't clear the bit by the MCU command. I need to 

reset  the BQ76940 power supply， the products are Good.  I try connect the TS2 to VC5X and TS3 to VC10X by the pull down 10K resistor. the the X-ready can be clear by the MCU.

   Question:   what condition can cause the X-ready indicate  “1” and can't be clear by the MCU  in no pull down resistor, it doesn't looks like  100%  occur ？

↧

UCC2804: I am looking for the maximum rated junction temperature for the UCC2804

March 28, 2019, 9:19 am
$
0
0

Part Number:UCC2804

Hi,

I am looking for the maximum rated junction temperature for the UCC2804D.

Please let me know thanks!

Sam

↧
↧

TPS2549Q1EVM-729: Why DCP mode is different than CPD mode

March 28, 2019, 9:31 am
$
0
0

Part Number:TPS2549Q1EVM-729

Hello team,

When you get a chance please see below customer question:

We have done initial testing on TPS2549 EVM and seems to work well but there is an issue with Samsung Tablets. On the Tab A, the DCP setting will charge tablet at 1.73A (with screen OFF, 1.22A with screen ON). However when configured to CPD-SPD Auto Switch Mode max charge current is limited to ~1A with screen On or Off. Same problem for older Tab 2 where DCP is 1.58A but CPD is again ~1A.

We are mostly looking at the CPD-SPD Auto Switch Mode but I tested other modes just to collect some data on that.

Have you seen this before where DCP mode is different then CPD mode? I wonder why it won’t draw the full current in CPD mode?

 

 

 

 

 

 

 

↧

BQ24092: Exposed thermal pad drawing

March 28, 2019, 9:34 am
↧
Search

LM46001-Q1: Overall current consumption without load for specific configuration

March 28, 2019, 9:35 am
$
0
0

Part Number:LM46001-Q1

Hello,

I have a question regarding the current consumption of the LM46001-Q1 @ no-load.

The datasheet indicates a typical operating quiescent current of 24uA under certain test conditions. In our application, the current consumption in the no load case is critical. However, our setup differs in several points from the specifications in the datasheet. The relevant section of our schematics is shown below:

The input voltage at Vin would be around 12V.

As it can be derived from the schematics, we are planning to have a switching frequency of 2.1MHz and a voltage output of 5V

Thus the values for R_fbt and R_fbb differ from the ones given in the datasheet, as well as the inductance (L102 with 6.8uH).

What would be the overall current consumption of this configuration without any load (i.e. I_out=0A)

What would be the behavior of the converter at very light loads regarding efficiency?

Best regards,

Johnny

↧

TPS43060: Abnormal switching frequency issue

March 28, 2019, 9:39 am
$
0
0

Part Number:TPS43060

Hi teams

My customer is using TPS43060 for new design and encounters some issue.

Customer design requirements is 12V-30V 10A output.

The issue phenomenon:

  1. They connect a 470Kohm resistor in RT pin to set the switching frequency to 122Khz but the actual switching frequency only the 1/2 of calculation. Are the formula in data sheet is correct or wrong?
  2. I wondering to know the gain of the current sensing resistor amplifier. Datasheet didn't give this parameter.
  3. The switching frequency becomes unstable when in higher load (2A). And the gate drive signal is also abnormal.
  4. What waveform we should seeing in RT pin when its normal? (If you can capture a picture is the best)
  5. Do our boot cap have UVLO protection? What's the threshold and machanism?

The and abnormal wavefrom is shown below: 

The schematic parameter:

↧
↧

LM46001-Q1: Pseudo Spread Spectrum using SYNC pin

March 28, 2019, 9:40 am
$
0
0

Part Number:LM46001-Q1

Hello,

I have a question regarding external clock synchronization on the LM46001-Q1.

We are examining the possibility to use the SYNC pin of the regulator with an external clock in order to have some kind of pseudo spread spectrum functionality.

The plan would be to provide the converter with an external clock, a few milliseconds after the converter has started. This external clock signal would then change in frequency with the goal to provoke some kind of spread spectrum. Would this be possible? Does the switching frequency adept on a cycle-to-cycle basis, if the external clock signal varies from cycle to cycle?

Best regards,

Johnny

↧

Battery reverse polarity protect and Over voltage protection

March 28, 2019, 9:56 am
$
0
0

Hi there:

Our customer would like to check the achievable solution or idea for wrong battery polarity and Over voltage protection solution , already using the TPL5110 as timer for power gating.

Any suggestion combination for this idea? 

Thanks again. 

↧

BQ24773EVM-540: No charging current

March 28, 2019, 9:56 am
$
0
0

Part Number:BQ24773EVM-540

I'm using a BQ24773EVM-540 to charge a battery at 512 mA. It was initially charging fine, however, I had to connect a 10 megaOhm resistor across the battery terminals for some reason, and I tried charging the battery in that manner. However, after doing this, the charge current dropped to zero. Now, even when I'm trying to charge the battery by removing the resistor, there isn't any charge current. I tried setting the charge current by using BQStudio, the device ACK is OK, and I'm able to set the charge current at 512 mA, however, no charge current is being read by the DMM. Also, I tried connecting the charger to an electronic load via a DMM and tried charging it at different currents, however, the charge current is still 0. Is there any way I can reset the IC? Or it is damaged and will I have to get a new one? Thanks!

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