Part Number:BQ51013B
Hi,
when I connected 150mA load output drops to 3.2V.
Plz help.
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BQ51013B: The circuit is designed for 500mA, but when I connected 150mA load Vout drops to app.3.2V.
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LM27222: Driving 2 N-Channel Fets switching a load of 18 Amps at 30 HZ
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reduce LDO ripple
Hello to all,
for a new project i need a LDO circuit. Input voltage is 48V, current shall be about 10Amps.
It must be switchable with short pulses 48V => 46V for about 100ms.
Attached circuit works, but output ripple is about 2V.
Because of the switching from 48V to 46V i can't use an output capacitor. What is the best, to reduce the ripple (other OP-AMP, put capacitor to....?)
Thanks and kind regards
Norbert
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Linux/TPS40400: How to recover from I2C SDA stuck low on TPS40400?
Part Number:TPS40400
Tool/software: Linux
Hello,
Background:
On our board we use TPS40400 buck controller as 1.1V source for the TMS320DM8168.
The TMS320DM8168 processor controls TPS40400 via I2C bus (PMBus interface).
Using a dedicated script, I have scheduled a device reset during the time TMS320DM8168 configures the TPS40400.
Means, the device reset comes during an I2C transaction between TMS320DM8168 (master) to TPS40400 (slave).
Occasionally (not always) after this reset, the TMS320DM8168 reports on the following error message describing communication error with TPS40400:
"SCSI subsystem initialized
omap_i2c omap_i2c.1: bus 1 rev4.0 at 100 kHz
omap_i2c omap_i2c.1: timeout waiting for bus ready
set_machine_constraints: failed to enable pmbus_vr
pmbus 1-0012: failed to register pmbus
pmbus: probe of 1-0012 failed with error -110"
Further investigation shows it happens since I2C SDA between TMS320DM8168 to TPS40400 stuck on low because of the reset mentioned above.
Means, at the times the reset comes when SDA='0', the SDA was stuck on this state, the TMS320DM8168 identify the I2C bus as "not ready" and reports the error message.
The TPS40400 I2C transmitter state must return to the idle state, waiting for a new master (TMS320DM8168) command.
(The I2C SCL is high after the reset as expected).
In other words, it was observed that if the board gets reset while I2C transaction between TMS320DM8168 and TPS40400 the SDA line remains stuck low until power cycle.
Unlike TMS320DM8168, the TPS40400 does not have reset input.
How can we to cause TPS40400 to release SDA line to high without power cycle?
I have made also a simple experiment in LAB:
a. I've reproduced the failure.
b. I shorted (momentarily) the SCL to GND (in order to generate a dummy I2C clock, hopefully it will release SDA signal).
c. Thankfully, as an immediate respone, the SDA changed polarity to logic high (the I2C channel is back on "start condition" state - SCL,SDA = high logic).
d. I have scheduled again my device reset.
e. No failure anymore
My questions are:
1. How to recover from I2C SDA stuck low on TMS320DM8168/TPS40400 (PMBus interface between TMS320DM8168 to TPS40400) as a robust and formal solution, without power cycle?
2. Is there a way to reset the I2C bus between TMS320DM8168 to TPS40400 (PMBus interface)? means, to bring it to "start condition" state - SCL,SDA = high logic.
3. In our reset case mentioned above, is there a way to return the TPS40400 I2C transmitter state to the idle state, waiting for a new master command?
Regards,
Daniel Daniel
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TPS82084: TPS82084/85 maximum load capcitor
Part Number:TPS82084
Hello.
In the data sheet, there is a paragraph about output capacitor, which states "no more than 150uF"(page 11). Is that includes all the load capacitors? for example, if my load is a FPGA which requires a 330 uF capacitor- can I used this part?
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TPS7A25: Soft Start and Overvoltage limits
Part Number:TPS7A25
Hi,
I am currently using TPS7A25 for 1.8V output generation from 5V line.
The datasheet mentions that the device has Internal soft-start to limit inrush current. But I could not find the time it takes the output to settle to final value (ramp up time)?
Also does the PG signal goes Low and device is turned Off when the output goes beyond ,say 10% or 15% above the desired Output Voltage. If not, can you suggest any regulator which has this Overvoltage shutdown feature? My Load requirement is 250mA and I need EN and PG features as well.
Regards,
Veerasamy
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BQ24232: Q2 State when battery is fully charged
Part Number:BQ24232
I am writing to ask what's the state of Q2 (from functional block diagram), or in other words, what powers OUT when the charging is complete. I have found some odd situations in the following Setup:
I am using BQ27426EVM to monitor the battery, and the charging, but I found that the voltage drop in RSense is much higher than expected when charging is complete.
Thanks for your help.
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BQ2946: BQ294624 - Temperature limit behaviour
Part Number:BQ2946
Hello,
we have to check if the overvoltage detector BQ294624 causes problems at overtemperature.
The data sheet shows +110 ° C and +85 ° C limits.
We expect that it works up to +110°C.
We have a running series production.
If the limit is +85 ° C, that could be a problem.
What is the right operating temperature and what can happen if it reaches +105°C?
Regards
Martin Hermann
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BQ35100: EOS for BQ35100
Part Number:BQ35100
Hi,
I'm currently trying to use BQ35100 with Li-SOCl2 and had some questions. Based my battery chemistry.
- Is it better to use normal coulomb counter to measure battery state of health instead of BQ35100 if I'm not using in EOS mode?
- Is there battery characterization need to be done for BQ35100 for EOS mode to work?
- Do I need to update it’s impedance value or it will do calculation by it’s own?
- It's mentioned that for optimal accuracy, the first eventnwhere the device updates it's impedance value is required to be when battery is full. If the battery was partically discharge, then the accuracy of the EOS detection is compromised. In this case, how does BQ35100 compensate the passivation of the battery?
Thanks,
Christina
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BQ78350-R1: Approaches to using custom balancing algorithm when using the BQ78350-R1? Can I individually control the AFE balance FETs directly via the BQ78350-R1?
Part Number:BQ78350-R1
1. Can I individually control the AFE balance FETs directly via the BQ78350-R1?
2. If not, can is the next best option to have a MCU share the 2C bus with the BQ78350-R1, and implement my own custom balancing algorithm?
3. Thoughts on that approach? What others are there for using a custom balancing algorithm when using the BQ78350-R1?
I want to balance whilst idle in addition to when charging
Many thanks
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BQ25606: connections
Part Number:BQ25606
Dear*,
i have few questions regarding BQ25606:
1) If we want always set the input current limit with ILIM (8) pin -> do we short or leave floating the D+ and D-?
2) When the BQ25606 in OTG mode do we have to pull up OTH (6) pin to Vbat(pin 13,14) or Vsys(pin 15,16) ?
a) what is the recommended pull up for OTG pin?
b) what is the recommended pull-down for OTG pin when in normal mode ? can be direct connected to GND?
3) Pin Ce when LOW charging enabled, how to disable charging? Float or pull up to ?
4) STAT pin 5 -> how can we know if the charge is complete or charger is in sleep mode?
a) if we use LED to indicate charging, error or charge complete , do we pull-up the STAT with 10k to REGN?
5) Can we use 10uF on REGN pin?
6) We see the calculation for RT1 and RT2 in DS, but where do we get the RTHcold and RTHhot ?
a) Is RTHcold the resistance of Thermistor resistance when 0°C and RTHhot when Thermistor resistance when 60°C?
b) what is the value of VT1 and VT5?
7) can we use 100n on BTST?
8) input capacitor , the DS suggest 22uf for 3A charging but the WEBENCH calculated only 1uf ??
a) What is the max input capacitor for charging from 5V 3A and 12V 3A? ( we don't charge from usb voltage)
b) if OTG is used what is the max capacitor on VBUS pin 24
Br,
David.
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LM2671: Effect of losing the catch diode
Part Number:LM2671
Could you explain whether the LM2671 will continue to provide a regulated output if I lose the catch diode (fails). As I understand your datasheet, this diode is only used to provide a path for storage inductor current during the off duty cycle. If I have a light load <20mA and the rated output is 500mA, I assume my duty cycle is very low. Would the storage inductor furnish enough average current during the on duty cycle, and the control loop compensate for the loss of the catch diode under these light load conditions? Thanks.
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BQ40Z80: Request for documentation improvements
Part Number:BQ40Z80
Dear TI Experts,
We were convinced to use the BQ40z80 as BMS in our system, due to its manifold of functions and its compact size. There are three engineers working on this task. After twelve weeks of development all of us are convinced that the documentation of the BQ40z80 needs to be reworked massively. It is simply not economical to work with the BQ40z80 if you have to hire someone for several weeks who digs through the documentation trying to understand the functionality the way it is written. Even though we have already invested twelve weeks of work and a lot of money for prototype PCB manufacturing, we are considering to switch to another IC before we reach a point of no return. You could save thousands of hours of work for lots of engineers out there, by offering some more information and better structure in your documentation. Usually, Texas Instruments is a source of high quality, concise and clearly structured manuals, we really like to work with. This is also the reason, why almost 70% of the ICs we are using, are manufactured by Texas Instruments. The technical reference manual for the BQ40z80 is none of the above.
Things we find worth to change with high priority:
a) In the technical reference manual we were not able to find out the data types of the individual values of commands returning "mixed" data.
b) In the technical reference manual almost no functional description in text form is available, the whole documentation consists of "state machines" written in tables. This feels like reverse engineering assembler code, not like reading a programming manual. While trying to understand the functional description of the chip functionalities, one is constantly looking up abbreviations of register names. When the register is found, the only description consists of a name in clear text. In one case, the only description was "reserved, do not use". In the end one can never be sure what the chip is actually doing, which is a massive deal breaker for a safety relevant component like the power supply.
c) We are right now using the schematic that is found in the datasheet that you offer to show our job students how a schematic should definitely not look like. Maybe you might want to clean this up before you officially release the chip. Nicer version of the schematic is attached as example of how it could look like.
Will you please be so kind as to informing us whether or not we can hope for a new, massively improved documentation in the next few month?
Thanks,
Jan
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TPS2546: difference between TPS2546 and TPS2549
Part Number:TPS2546
Hi,
There are few questions about TPS2546 and TPS2549:
1. what is the difference between TPS2546 and TPS2549?
2. Can TPS2546 or TPS2549 support 2.4A apple charging spec?
3. Can TPS2546 and TPS2549 can support power saving lower than 0.5W consumption at standby mode?
Great thanks for your help.
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TPS54331: what may be the cause of the abnormal operation of the TPS54331 circuit under the -40 degree cold environment test?
Part Number:TPS54331
dear sir
problem: what may be the cause of the abnormal operation of the TPS54331 circuit under the -40 degree cold environment test?
circuit :
ph picture:
discription
Device in the low temperature test chamber, when the temperature set to to 40 ℃, the device is powered on, one board can normal work, another board is not normal.Input 5V is ok. There is no problem with other circuits except TPS54335,The output is connected to 4G module, and TPS54331supports -40 degrees for industrial level.Other resistance and capacitance components are also industrial grade.
The two board have been tested twice. For the first time, only one board has output, and for the second one, two boards cannot work.Remove the device, leave it at room temperature for a period of time, and return to low temperature test , both are normal after power on.
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Do we have a part similar to CAP019DG?
Hi team,
Do we have a part similar to CAP019DG?
Datasheet as attachment.
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James
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IC Charger
Hello!
I’m looking for an advice in choosing 1S-3S LiFePO4 charger IC that will operate in 12V-24V range. The IC must have all kinds of cell protections(overvoltage, undervoltage and overcurrent) and also an external thermistor for cell temperature monitoring. It will be great if the IC will also be capable to calculate and store the battery pack capacity.
The most fitting for my requirements I was able to find are the (BQ25703A)
Thanks and best regards,
Mikhail
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ATL431LI: For Li battery in 3.3V out application
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TPS65185: TPS651851 V3P3 load switch question
Part Number:TPS65185
Dear Sir
We are working on a Eink panel PMU TPS651851 Smart phone, and customer measure afollowing V3P3 load switch sequence
It is strange that V3P3 have a short rise then discharge, then start. We had check that I2C write only one time and it is at the V3P3 stable situation
Could you please give some advice how to remove this rising.
Thanks
BR
Bruce
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TPS7A66-Q1: Charger for nimh battery
Part Number:TPS7A66-Q1
Dear TI Experts,
I am using TPS7A66-Q1 to charge 3 series nihm batteries~
And I need 150mA charge current~
My TPS7A66-Q1 is very hot,and the current is 500mA
I‘d want to know if I want to use LDO to charge batteries, do you have any suggestion how to do the current limit?
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