TPS63070: Boost Converter and Related Design

Hi Ayla,

Can you share the details about the solar module you are using (short circuit current, open circuit voltage, maximum power)? The TPS63070 is just a buck-boost converter, and only in some cases it can be configured to perform simple MPPT, see this app note:
www.ti.com/.../slyt478

Otherwise, I think some of the the energy harvesting devices would be more suitable in this case. For example BQ25570 contains an MPPT front end, battery management and a buck output.

Best regards,
Milos

Thanks for the valuable infomation, The details as follows

1)Short Circuit Current Isc: 0.402A

2)Open Circuit Voltage:12.59V

3)Maximum Power:3.84W

And one major issue is that the Charging IC operating voltage   Vmax is 6v, but the Solar panel Operating voltage is  12.59V and the Solar panel is designed for 6V when under Load, Can I integrate the system in this conditon with the open circuit voltage greater than Vmax of the Charger IC, Provided the Load is Continuosly Always on.

Attached is the scrren shot, Thanks.

Hi,

The BQ25570 as suggested, will not fit into our design as the requirements are way high, The BQ25570 has
Vin Max =5.5V, But our input Solar panel available voltage is way head at 12.59v
and the Ichg is typically 230mA but atleast 500mA is desirable for Fast charging the battery.

Can you please suggest me a Boost charger for the operation unlike MPPT charger , the input must be a Solar panel operated one.

Hi TI,

Thanks for the information, As suggested by you, will go with TPS63070, Buck-Boost Convertor, My question is that the Schematic which I have Shared, is that okay,

There are various Schematic Flow diagram as follows Iam considering

1)SOLAR->TPS63070->POWER PATH CHARGER->BATTERY &SYSTEM LOAD

(OR)

2) SOLAR->POWER PATH CHARGER->TPS63070->SYTEM LOAD

One of the important considerations I had, while going for the Boost converter is,uniform power supply for the WSN Node and for all the sensors at different Charge levels of the battery, So the Flow 1, does not maintain a uniform supply,when Battery Voltage level is Far low below 3.3V and in absence of Solar.

But Flow 2 Maintains a uniform supply at all the Charge levels of the battery, But Charger does not function at all the input voltage levels,as the charger Vin (MIn) is 4.5v, so below 4.5v, the charger does not charge the battery,This is a big drawback.

The other Flow diagram i'm considering is

3)SOLAR->TPS63070->POWEWR PATH CHARGER-> BATTERY ->TPS61291->SYSTEM LOAD

Im keen on flow diagram 3, will this be a good solution for the design im considering,

Please let me know your thoughts.

Hi Ayla,

Have you checked the charger devices from the link from my previous post? There could be a solution where you can use only one device - a charger device with a solar input (performing MPPT) and a regulated buck/boost output. This would be the simplest and most efficient solution. You may create a new thread and ask for this, and experts for battery chargers can give you a recommendation.

Other than that, I would go for the 1st solution - using the TPS63070 to provide fixed voltage for the charger, and the charger should have integrated converter to provide fixed supply for your system. Without knowing more details (system voltage for example) it is difficult to give recommendations.

Best regards,
Milos

Thanks Milos,

I would go with the suggestion of TP63070,Also I have looked into the link that you have provided, as mentioned the BQ24650 was the choice.

Sharing more details of the system

1)System voltage:+3.3V fixed

2)Sub-Ghz Module+ Microcontroller:+3.3V

3)Using a Fixed LDO of +3.3V to regulate the System voltage from the Output of the Battery charger.

Sure, will Create A new thread on this topic.

Hi Ayla,

In case you decide to use TPS63070, then your first schematic should be fine. Maybe the power path charge controller can already provide 3.3 V for your system, so you do not need and LDO.

If you want to use an LDO directly connected to the battery to generate 3.3 V, it might be a better solution to use a buck-boost converter instead. That way you can discharge the battery deeper, while always keeping regulation. Using an LDO means you will be able to discharge the battery only down to 3.4-3.5 V or so, after which the LDO will not be able to regulate the 3.3 V output.

Best regards,
Milos

Hi Ayla,

I think going with Simple link family is a good start, but to be sure you should ask for recommendation from our μC experts.

Best regards,
Milos

Yeah I've already tagged the microcontroller section, Else any specific section I should address?

Hi Ayla,

Tags are used for the search function mostly. If you need information on devices, the best way is to open a new thread in the appropriate forums:
e2e.ti.com/.../
e2e.ti.com/.../

Best regards,
Milos

Hi Ayla

We haven’t heard back so we're assuming this answers your question. If so, please click the "This resolves my issue" button. If not, just post a reply below, or create a new thread if the thread has locked due to time-out.

Thanks and regards,
Milos