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Hi,
I'd like to use a TPS62480 for supplying a load with a variable voltage via a DAC.
1) I understand that this type of operation is outside the intended scope of this package but if it's possible, I would like to know if there is a way to control Vout using a DAC.
2) If so, is it controlled by a current of a voltage, with which pin ?
3) Can the current simulations models for the TP62480 for Pspice for TI simulate this behavior ?
Here is my current design:
Vin is delivered with a 3.7V battery, VDD is at 3.3V, and the load is 0.6V.
I would like the TPS62480 to deliver below 9W power to the load.
Thanks
Hi Alex,
Yes, this is possible with many DC/DCs. Here is my app note on the topic, which you can find on the above product folder: https://www.ti.com/lit/an/slyt777/slyt777.pdf
We also have the TPS62869 and TPS62870-Q1, which adjust the voltage via I2C if that is easier.
Finally, the TPS62867 is a newer and smaller device and would be my recommendation instead of the TPS62480.
Thanks,
Chris
Hi Chris,
I assume Vfb in the (1) formula is fixed at 0.6V, is it correct ?
If my load is purely resistive, won't my control voltage I apply with the DAC also depend on the load's current value ?
I wish TPS62869 and TPS62870-Q1 were available but they seem out of stock, I must make do with TPS62480 for this design.
Thanks,
Alex
Yes, 0.6V in that equation.
No, the DAC voltage is independent of the load current. This is the same as for normal Vout regulation--the IC regulates the output voltage with a varying load current.
TPS62869 and TPS62870-Q1 use I2C to adjust the output voltage. You could use this same DAC circuit on the TPS62867 and/or TPSM82866A.
I can't see what stock quantities you can see, but I think we should have some of the TPS62867 and/or TPSM82866A on ti.com. How many do you need?
Chris