EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: fubar.gr on October 06, 2014, 05:21:05 pm
-
I am trying to use the TPS2511 (http://www.ti.com/product/tps2511) in the following topology:
(http://i57.tinypic.com/28srggg.jpg)
This is my board:
(http://i62.tinypic.com/9899mu.jpg)
It is not working. Any ideas why?
-
5v not hooked up?
Seriously?
Is that all the information you have to present?
-
Sure you have 5V Input? Hook up the 5V input to a bench supply.
What if it's a dodgy chip or solder joint? Can you confirm this?
Also you may want some bulk cap (56-100uF?) on the input & some 10n, 100n decoupling on the IC.
-
This is the schematic:
(http://i61.tinypic.com/14y7rmh.jpg)
I've double checked everything. Nothing is shorted and everything seems soldered properly. I haven't tried another chip yet.
-
Out has to be connected to the USB port, it is the switch output, otherwise the chip does not see any load and stays off.
-
Chip backwards. Bad solder joint. Fried chip (should still get slow charging..). Why, exactly, are you bothering with a chip when all it's doing for you is putting a resistor across the data pair?
Out has to be connected to the USB port, it is the switch output, otherwise the chip does not see any load and stays off.
Think that one through, then ponder why they have a 'no switch' example in the datasheet..
-
You guys are right.
It is not possible for this topology to work.
I've made this board too, where the voltages on the data pins can be manually adjusted with the two trimpots.
(http://i57.tinypic.com/155jazr.jpg)
If the voltages are adjusted while the mobile phone is already connected, it won't start drawing more current. It has to be disconnected and reconnected again.
So even if the IC is setting the voltages correctly, it has no way to disconnect power to the phone, therefore it can never work.
Why, exactly, are you bothering with a chip when all it's doing for you is putting a resistor across the data pair?
This IC is also trying several combinations of voltages on the D+ and D- pins.
-
Why, exactly, are you bothering with a chip when all it's doing for you is putting a resistor across the data pair?
This IC is also trying several combinations of voltages on the D+ and D- pins.
It cannot do so effectively in that configuration. You may as well short D+ and D-, because that's more or less what it's good for used like that. (actually, I'm not sure which charging mode it attempts first and it's fairly irrelevant, as it's a waste of silicon unless it actively controls the port)
-
use the right chip for the job.
ive used the TPS2513 in a few things lately, it should work fine in your application and IIRC its cheaper too.
-
Connect te output pin to the vbus, cut the trace to the 5v rail and use the enable pin