Can I change BQ24008PWP with BQ24002PWP?

Thread Starter

turgut

Joined Nov 4, 2022
28
Hello,
I have a question.
Im using BQ24002PWP Charger IC you can see in the schematic which I add. But I want to change IC with BQ24008PWP Charger IC because of TMR_EN feature.(to out of order the timers.)
BQ24002PWP use 2 individual LED.
BQ24008PWP use 1 bi color LED.
In datasheet write "The output stage is totem pole for the bq24001 and bq24003 and open-drain for the bq24002."
and "The output stage is totem pole for the bq24007 and bq24008."
I dont know what the mean is totem pole. I looked a little but didnt understand too much.
So the question is can I change BQ24002PWP with BQ24008PWP without changing my circuit? If I can, can you describe or draw it how?

Schematic;

BQ24002_BQ24008_Schematic_for_TI.png

Also what i want with more visual;

BQ24002_BQ24008_Schematic_for_TI1.png
 

LesJones

Joined Jan 8, 2017
4,174
A totem pole output can drive the output both towards the positive rail and the negative rail. An open drain can only drive the output in one direction. If the output mosfet is a N channel device it can only drive the output towards the negative rail. If it is a P channel device it can only drive the output to the positive rail. If output current is required in both directions a pull up or pull down resistor is required. You can think of the mosfet as an SPST switch connected to either the positive rail or the negative rail.

Les.
 

BobTPH

Joined Jun 5, 2013
8,765
The single totem pole output can still drive two individual LEDs, but one needs to go to ground and the other to V+. You would have ti make that change for your status LEDs to work.
 

Thread Starter

turgut

Joined Nov 4, 2022
28
I tried to drive in totem pole circuit to see results how it works. I used 2 seperate leds like bi color led in a circuit with voltage supply. In device, I think stat1 cant drive because its for power led. Its only turning ON when power is ON. But also tried for Stat2 and it didnt work. Stat2 pin has stabile 4.9 volts. So its only turning ON like power led. The circuit is true i checked that. Also we are normally using that circuit for lab tests. So im open to different views.
Thank you for now and happy new year.
 
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