TPS62913: TPS62913 inverting configuration

Hi Sim, 

Do you want this schematic to be reviewed? Can you share a proper image or PDF? The above file disproportionate. 

Regards,

Gautam

what is the best way to insert my schematic? i try to upload the file, but it seems like the resolution is bad

Hi

I got the schematic from

TPS62913 Inverting Buck Boost EVM User Guide

Figure 5-1.

I want to toggle the TPS62913 on off via the enable pin. 

I will change the Vin at J2 and the Vin at pin4 of Q1B to a LVTTL signal. Would like to check if this is correct. 

Hi Sim, 

Its either short J2 1-2 for enabling else short J2 2-3 for disabling. Section 1.2.2 of the same document describes this in detail. 

Regards,

Gautam

Hi, 

Allow me to rephase my question. 

I will be doing a new PCB and not using the eval PCB.

In this iteraction, I want to toggle the enable pin via a LVTTL signal instead of setting the physical jumper to turn the device on/off. 

How should I modify this schematic to achieve this purpose. 

Generally, you have:

1. A micro-controller that would enable/disable EN  with the help of GPIO or

2. Some input logic from Vin with a simple voltage divider that would automatically disable the buck if the Vin is lower than the expected threshold.

I hope this answers your question. 

Regards,

Gautam

Hi, 

I will be going with option 1. I just want to verify how should I modify the below schematic to do this? 

TPS62913 Inverting Buck Boost EVM User Guide

Figure 5-1.

I have modified the schematic. (section in red)

Can help to verify if this is correct. 

You can either do this (heavy on BOM) or simply connect the GPIO directly to EN. If required, you can add a 100K pull-down to EN pin. 

Regards,

Gautam

Hi, 

If I understand correctly, I can remove Q1 and Q1A and connect the EN pin to the output of a mircocontroller? 

Correct!

Hi, 

I more clarification. 

The microcontroller output is a positive signal while Vout is a negative 3.3V. I thought we will need the Q1 and Q1A to translate as the volatge translator? Correct me if I am wrong, i might have interpreted section 1.2.2 incorrectly.  

TPS62913 Inverting Buck Boost EVM User Guide

One last qn. 

In the intialisation of the microcontroller, the EN pin will be in tri state (high impedance state ). Will the tps62913 be turned off when the enable pin is in the high impedance state? I want the tps62913 to be off when the enable pin is the tri state mode.