Ic behaviours/properties

[bluestone]

I was hoping we can make some few notes on how each pinout of ics behave, incase they are not functioning well or in good shape.
For example TPS51125, pin 23 is PGOOD, how much voltage should be read there if its working alright on how much voltage should be there if it is faulty.
Let's share our ideas

[dj_ricoh]

Re: Ic behaviours/properties

It depends .
If you got a short on vreg5 and pin pgood 23 does go there , it will be 0 even if the chip is good.
Now isolating the vreg 3 and 5 its the problem because many pins go there .

[dj_ricoh]

Re: Ic behaviours/properties

Or maybe pgood its the feedback from vreg. Off

[bluestone]

Re: Ic behaviours/properties

I have problem with some toshiba mahine using tps51125, I read 3.3v, 5v from all the places but the laptop only works on battery, it can't recognize the charger and it won't charge. I realize that pgood reads 4.6v on the tps51125

[dj_ricoh]

Re: Ic behaviours/properties

What model?

[bluestone]

Re: Ic behaviours/properties

Toshiba satellite C660-198

[highpulse]

Re: Ic behaviours/properties

well then TPS is ok . your problem is on DC detect circuit . chek carefully if you got LDO on the charger IC , specially near the charger IC you will have a big ceramic capacitor , were you must have this 5 volts present . but this is something on dc detect circuit and not main regulator line