BQ771611 BQ294700 difference, output drive

Gregory Grzesiak

Other Parts Discussed in Thread: BQ40Z40

As in the subject, what are the differences between those two except package, price, release date and Cin recommended values?

Also can you provide me with output pin drive characteristics? The datasheet only states currents in Lo state when the pin is at the supply potential and the opposite with Hi.

Best regards

over 9 years ago

0 WM5295 over 9 years ago

TI__Guru 54715 points

The function of the 2 parts is the same as described in the datasheet. See the parameters of interest for similarities and differences.

The output is either a push-pull driver operating between GND and a roughly regulated voltage or an active low open drain drive. See the block diagram, specifications and figure 6 (or 7). The test conditions show a low current voltage and high current

0 Gregory Grzesiak over 9 years ago in reply to WM5295

Prodigy 170 points

Hi WM5295

First sentence not necessary.

Second...

Third, on both we have push-pull...

...

I asked about differences and output drive characteristics, please answer my questions, I don't have the data that you have there.

Best regards

0 Miguel Angel Rios over 9 years ago in reply to Gregory Grzesiak

TI__Expert 4640 points

Hi,

The differences beyond what you pointed out are none except package as that is important for this device. Also DS mentions that it is 6V min for output drive when it is ACTIVE high. Does this answer your questions?

Miguel

0 Gregory Grzesiak over 9 years ago in reply to Miguel Angel Rios

Prodigy 170 points

Hi Miguel

So far so good, but since there is no output characteristic I need to ask specifically about it;

-In no over-voltage condition, "0" at the output, what maximum voltage can I expect when the output sinks 20uA, at normal and maximum operating temperature?

-in overvoltage condition "1" at the output (6Vmin) there is a statement that the maximum of 4.5mA flows out when the out pin is tied to ground, what are current capabilities when the pin stays at those 6V? (assuming 4s pack), what is the minimum value, and is it dependent on power supply/output voltage?

Best regards

0 Gregory Grzesiak over 9 years ago in reply to Gregory Grzesiak

Prodigy 170 points

BDW
Why there is a difference on recommended Cin?

0 Miguel Angel Rios over 9 years ago in reply to Gregory Grzesiak

TI__Expert 4640 points

Hi Gregory,

I believe that for the plots you are asking below you will have to refer to the DS, and we only have figure 7 showing VOUT vs VDD not with respect to Iout current.

Miguel

0 Gregory Grzesiak over 9 years ago in reply to Miguel Angel Rios

Prodigy 170 points

Hi Miguel
Does it mean that TI invests amounts in new IC development and in the end the performance is not verified?
I would expect to have tons of such graphs in various variants and all for joust one pin.
What is your relation to development department?
Can you contact them if necessary? (like now, for example)
This is surely not exaggerated, this case may be simple but there are other developments to come and it's very risky to even touch TI's chips if it's a black "typical application" box that I have to measure for myself!

Best regards

0 Miguel Angel Rios over 9 years ago in reply to Gregory Grzesiak

TI__Expert 4640 points

Hi Gregory,

Maybe we can take a step back to see what are you trying to accomplish with this data. Is there an application concern that you are facing that we can help you on?

Miguel

0 Gregory Grzesiak over 9 years ago in reply to Miguel Angel Rios

Prodigy 170 points

Hi Miguel

I wanted to use the output pin differently than it is on the DS, particularly to pull some current when the output is in LOW state. If the current is not pulled then this would indicate device failure or some other abnormal state. As you see, knowing output characteristics could help here a bit.

Best regards

0 Miguel Angel Rios over 9 years ago in reply to Gregory Grzesiak

TI__Expert 4640 points

What did you want to pull down? Not a fuse?

0 Gregory Grzesiak over 9 years ago in reply to Miguel Angel Rios

Prodigy 170 points

Hi Miguel

Not a fuse, joust some nA of current but with limitations on how the output of BQ771611 can rise.

Best regards

0 Miguel Angel Rios over 9 years ago in reply to Gregory Grzesiak

TI__Expert 4640 points

Hi Gregory,

Apologies for the delay, I believe you should be able to drive anything as the Iout sink is spec'd at the mA range so giving you a wide vareity of options.

Miguel

0 Gregory Grzesiak over 9 years ago in reply to Miguel Angel Rios

Prodigy 170 points

Hi Miguel
It's fine I have already sorted it out.
Could you please look at another post of my that floats there for a week with no answer? It's called "BQ40Z40 Zener between VCC and PCHG".

Best regards

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BQ771611 BQ294700 difference, output drive