TPS62868: Vout register

Hi, 

1) Then, Can I use same voltage before and after startup by just setting the VSET resistor without using I2C?

For example, If I use 0.55V both before and after startup, I need to connect 205kohm to VSET pin.

Then, 0x8C(0.55V) value is set in Vout register1 automatically?

(I want to set same voltage between before start up and after startup without changing the register value by I2C)

2) Then Vout2 register is set only by PG device?(VID pin is pulled up to high) ex)TPS6286800CRQY

3) I was wondering if I could know what situation change the vout after start up?

Could you let me know the example?

Hi,

Yes, you don't need the I2C to operate the device.  If you don't want the I2C, you might look at the TPS62865 or the power module versions, TPSM82864A.

1. Yes

2. The Vout2 register is fixed at 0.9V.  You can only change this voltage through I2C.  For versions with PG, this register is not used at all since there is no VID pin to select it.

3. Many processors dynamically change their voltage to change their performance.  Section 4 of this app note shows an example: https://www.ti.com/lit/an/sluaae9b/sluaae9b.pdf

Chris

Hi,

Thanks for recommendation, but I need a buck converter which is Vout=0.55V for LPDDR5 VDDQ.

Ah, you're right.  0.55V is just below what those 2 devices can output.

Chris