Hey guys, I have trouble figuring out the purpose of some components.

1. HIH-5031 Humidity Sensor
http://www.farnell.com/datasheets/1676925.pdf
Under the typical application circuit, was wondering what is the minimum load between the -ve and +ve terminals for?

2. TPS61221DCK
http://www.ti.com/lit/ds/symlink/tps61222.pdf
Under the typical application circuit for the fixed output voltage option, was wondering what C1, C2, and L1 are for?

PLEASE HELP!

 

Are you going to be frustrated for the rest of your life or are you going to become happymember one day?

 

1. HIH-5031 Humidity Sensor
http://www.farnell.com/datasheets/1676925.pdf
Under the typical application circuit, was wondering what is the minimum load between the -ve and +ve terminals for?

You need better glasses, the minimum load is between OUT and -Ve, and it has to be 65kΩ or less.

2. TPS61221DCK
http://www.ti.com/lit/ds/symlink/tps61222.pdf
Under the typical application circuit for the fixed output voltage option, was wondering what C1, C2, and L1 are for?

C1 is input capacitor, L1 is the main inductor that stores energy for boosting the voltage and C2 is the output capacitor where this energy gets dumped.

 

I know this is ambiguous when they say minimum load is 65kΩ.
But I think they are correct and mean 65kΩ or greater than 65kΩ.

 

Now that I think about it it makes more sense to be minimum load resistance a.k.a. maximum load. Wonder why even such rescpectable company as Honeywell can't make correct and inambiguous datasheets.

 

You need better glasses, the minimum load is between OUT and -Ve, and it has to be 65kΩ or less.
C1 is input capacitor, L1 is the main inductor that stores energy for boosting the voltage and C2 is the output capacitor where this energy gets dumped.

Thanks for you explaination, but is there any particular reason why is the voltage for C1 and C2 specified to be 6.3V at 10µF? I understand that X5R stands for the capacitive tolerance and max/min operating temp.

And for the minimum load question, sorry for that mistake on my part..
But by I'm having a hard time udnerstanding "minimum load". Shoudln't it be like "Maximum load" or something? And in that way, isn't the resistor just meant to resist the voltage passing to the -ve terminal?

(Sorry for my bad english, English isn't my first language. )

 

Now that I think about it it makes more sense to be minimum load resistance a.k.a. maximum load. Wonder why even such rescpectable company as Honeywell can't make correct and inambiguous datasheets.

Because they hire little kids straight out of skoooool to write the datasheets.

 

Thanks for you explaination, but is there any particular reason why is the voltage for C1 and C2 specified to be 6.3V at 10µF? I understand that X5R stands for the capacitive tolerance and max/min operating temp.

The voltage ratings are just what they used in the test circuit from which the typical curves are obtained, you need to select proper voltage rating according to your input and output voltages.

Look at pages 13-15 where they show the design process, C1 minimum recommended value is 10uF, C2 should be at least 4.7uf, but 10uF is reccommended.

 

I know this is ambiguous when they say minimum load is 65kΩ.
But I think they are correct and mean 65kΩ or greater than 65kΩ.

I haven't looked at the data sheet, but it could be either way. A number of circuits have to have a minimum load, as in minimum current draw, in order to work properly. Perhaps that is the case here. Others, of course, have a maximum load and you shouldn't draw more than a certain current from them. There are probably enough clues in the data sheet to figure out which is meant, but it definitely should be clearer.

 

I interpret it as meaning 65KΩ minimum load (resistance). Otherwise they would need to state a maximum load, but I think the maximum load is open circuit or infinite resistance.