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Topic: Help to identify IC (LDO regulator) (Read 553 times) previous topic - next topic

azelogose

Hello to everyone,

   I have an LSM6DS3 accelerometer and I'm trying to identify its voltage regulator in order later on to look for its datasheet.

Can anyone help me to match "S20F" with a part number or tell me where this logo belongs to?

Thank you

PS I found that it may be a Ricoh R1162N201B but I don't feel any confidence at all that I am right.


Wawa

Why do you want to know that.
Seems a 3.3volt/150mA (max 6volt in) linear regulator, commonly used on modules like that.

What would worry me more is that that 3.3volt logic module doesn't have IO level translators.
So you can't connect it directly to a 5volt Arduino.
Leo..

ted


azelogose

#3
May 21, 2018, 02:00 am Last Edit: May 21, 2018, 02:01 am by azelogose
Why do you want to know that.
Seems a 3.3volt/150mA (max 6volt in) linear regulator, commonly used on modules like that.

What would worry me more is that that 3.3volt logic module doesn't have IO level translators.
So you can't connect it directly to a 5volt Arduino.
Leo..
This module is working perfectly with an UNO board using its 3v3 line!

My next step is to power it up directly from an li-ion battery which when it is fully charged I get 4.2V
Except this 3.3V pin there is also a VIN pin and by reading the datasheet I can decide if that 4.2 voltage is within boundaries.

Azelo

Wawa

This module is working perfectly with an UNO board using its 3v3 line!

My next step is to power it up directly from an li-ion battery which when it is fully charged I get 4.2V
Except this 3.3V pin there is also a VIN pin and by reading the datasheet I can decide if that 4.2 voltage is within boundaries.
Do you mean you power the module with 3.3volt from the Arduino Uno on the 3.3volt pin of the module.
That's fine, because an Uno can deliver 150mA from that supply pin, and the module draws nowhere near that.
The problem is the IO pins. They expect 3.3volt logic. And you're connecting 5volt to them.

V-in on that module is the input of the onboard 3.3volt regulator
The upper boundary of those 5-pin regulators is usually 6volt, so no problem there.
The lower boundary (dropout voltage), who knows.
Try with a 3.5volt (flat) battery, and see if the 3.3volt pin is still 3.3volt.
Or connect V-in temporary to 3.3volt of the Arduino, and measure the 3.3volt pin of the module.
Then you can work out the real dropout voltage. I expect it to be ~0.1volt.
Leo..

azelogose

Thank you for your advise Leo, I'll give a shot.

I still believe finding that datasheet would be better.

wvmarle

As long as this is the ONLY module on the I2C bus, and you do not have the internal pull-up enabled on the I2C pins, nor any other pull-up to 5V, there should be no problem, as the I2C bus is open collector.

It's not good practice, nonetheless. You better add a level shifter (or use a 3.3V Arduino).

Those sensors normally work quite well at voltages below 3.3V, that's why you can connect them to 3.3V and all still works fine.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

srnet

The marking will normally listed in the datasheet for the device.

Some manufacturers have SMD code lookup tables for their own devices, but I have not come across a look up table that covers all manufacturers.
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

azelogose

The marking will normally listed in the datasheet for the device.

Some manufacturers have SMD code lookup tables for their own devices, but I have not come across a look up table that covers all manufacturers.
This is why I'm trying to match this logo with a manufacturer and later on come in contact with them.

This is not a typical ST nor a Motorola. What else can it be?

azelogose

As long as this is the ONLY module on the I2C bus, and you do not have the internal pull-up enabled on the I2C pins, nor any other pull-up to 5V, there should be no problem, as the I2C bus is open collector.

It's not good practice, nonetheless. You better add a level shifter (or use a 3.3V Arduino).

Those sensors normally work quite well at voltages below 3.3V, that's why you can connect them to 3.3V and all still works fine.
I use both INT1 and INT2 pins connected as EXTINT (D2 and D3) with pull-ups enabled. Nothing looks suspicious and it works.
As it is mentioned in LSM6DS3 datasheet typical Vcc is 1.8V and max rated should not exceed 3.6V

If I use a barebone ATmega setup by extracting UNO's IC and placing it on a breadboard with a battery supply (that li-ion with 4.2V) will I be OK or I have also to add a voltage regulator?

wvmarle

Voltage regulator required, of course. 4.2V > 3.6V. That's why.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

azelogose

#11
May 21, 2018, 04:02 pm Last Edit: May 21, 2018, 04:05 pm by azelogose
Voltage regulator required, of course. 4.2V > 3.6V. That's why.
I meant a voltage regulator before ATmega328, I don't have any intention removing LSM module's regulator.

What I want is to read its datasheet

ted


srnet

This is not a typical ST nor a Motorola. What else can it be?
There are quite a few manufacturers of regulators.

Go to somewhere like Element14\Farnell and do a parameter search for likley candidates, you will quite a range of manufacturers, but maybe not all of them.
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

ted

I meant a voltage regulator before ATmega328, I don't have any intention removing LSM module's regulator.

What I want is to read its datasheet

Unknown chinese/Hong Kong producer

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