WEBENCH® Tools/CC2640R2F: power supply design for my embedded system

pragash sangaran78

Part Number: CC2640R2F
Other Parts Discussed in Thread: TPS63051, LP3923, TPS82740A, TPS62748, TPS62746, TPS62743, TPS62801, BQ25120, BQ25100, BQ51013B, BQ51050B

Tool/software: WEBENCH® Design Tools

my embedded system contains:

CC2640R2F - 1.8V and 0.03A

module A - 1.8V and 0.2A

Module B - 1.8V and 0.002A

module C - 1) 3.3V and 0.4A

2) 3.3V and 0.1A

TI power WEBENCH Power Architect proposed to use LM3670-1.8V and TPS63051. However, LM3670-1.8V is not a multi-output regulator so all the 1.8V output load needs to share the voltage. Due to this, i cannot turn off each module completely to save power.

on the other hand, im looking at PMIC and found a really cheap PMIC, LP3923. This PMIC have only single switching regulator and the rest are linear regulators (LDOs). Due to this the power consumption will be high!

This is for wearables so the design have to be small, low power/high efficient and also low cost.

Please help me with my power management issue.

over 6 years ago

0 Severin Suveren over 6 years ago

TI__Mastermind 23730 points

Hi pragash,

I'm moving this thread to the Power Management forum where you'll get more appropriate support.

0 Chris Glaser over 6 years ago

TI__Guru*** 145580 points

Hi Pragash,

Optimizing the power consumption by turning off various rails and maintaining the smallest size are conflicting design goals. However, we have solutions that can do either, so you can choose what is best for your application.

Do you have a height limit? What is your power source (battery type and voltage range)?

Please see the TPS82740A/B for a very small buck converter, which includes a load switch. For lower height, please see the TPS62748 and TPS62746 and TPS62743.

For your higher current needs, the new TPS62801/2 is extremely small and low height.

0 pragash sangaran78 over 6 years ago in reply to Chris Glaser

Expert 2725 points

Do you have a height limit?

i dont have height limit.

What is your power source (battery type and voltage range)?

our battery range is 3V - 4.35V and 550mAh @0.2C. This is a li-poly battery.

0 Chris Glaser over 6 years ago in reply to pragash sangaran78

TI__Guru*** 145580 points

Thanks for confirming.

For the 1.8V rail, TPS82740A and TPS62748 would be most useful for you.

For the 3.3V rail, you need a buck-boost like TPS63051 to make this rail.

You can use load switches to turn off and disconnect your various sub-systems.

0 pragash sangaran78 over 6 years ago in reply to Chris Glaser

Expert 2725 points

hi Chris,
thank you very much. im new to power supply design. i saw all this ICs have single Vout going to the load.

could you please tell me how can i switch between loads with this single Vout?

0 Chris Glaser over 6 years ago in reply to pragash sangaran78

TI__Guru*** 145580 points

You can see the figure in section 11.2 of the TPS82740 D/S to see how you would use the load switch in a typical application.

0 pragash sangaran78 over 6 years ago in reply to Chris Glaser

Expert 2725 points

Thanks Chris. you are awesome!

0 pragash sangaran78 over 6 years ago in reply to pragash sangaran78

Expert 2725 points

Hi Chris,
i have few questions here.
1) I cannot go to the link you sent on TPS63051. Its saying page not found. can you help with that?
2) Since the regulators proposed is suitable for switching up to two outputs, im planning to use it to switch between module A and module B (TPS82740A) and module C between two separate 3.3V ( TPS63051). Due to this, i need separate regulator for the MCU. Do you have any low profile (smaller size), high efficiency, regulator with battery charging circuitry and wireless charging circuitry (inductive charging and etc) in it? The MCU and current rating is given below:

CC2640R2F - 1.8V and 0.03A

BR
pragash

0 pragash sangaran78 over 6 years ago in reply to pragash sangaran78

Expert 2725 points

hi Chris,
i have more update here. i found datasheet of TPS63051 and realize that it doesn't have the load switching similar to TPS82740A. Eventhough 3.3V is for one module, i would to have load switching to save current as RF consume 0.4A. I know TPS82740A can do the job for 3.3V but i need boost converter to keep the voltage at 3.3V eventhough the voltage drop to 3V (the battery discharge cut off voltage).

0 Chris Glaser over 6 years ago in reply to pragash sangaran78

TI__Guru*** 145580 points

Hi Pragash,

Thanks for the feedback.

TI also makes discrete load switches that are very small. You can use one of these. Also, is it possible to turn off the various sub-systems, so that they don't draw their full current?

Finally, it's a little unclear what your modules (A/B/C) are. Are these different products? Or different subsystems in 1 product?

0 pragash sangaran78 over 6 years ago in reply to Chris Glaser

Expert 2725 points

it's a little unclear what your modules (A/B/C) are. Are these different products? Or different subsystems in 1 product?

it's different subsystem in one product. I'm designing an embedded system with module A, module B and module C, TI MCU+BTLE IC and TI power management IC.

0 pragash sangaran78 over 6 years ago in reply to pragash sangaran78

Expert 2725 points

hi cHris,
i replied this yesterday but not sure why my answer didnt get through.

it's a little unclear what your modules (A/B/C) are. Are these different products? Or different subsystems in 1 product?
its different subsystem in 1 product. im designing an embedded system which contains module A, B and C together with CC2640R2F and TI power management.

0 Chris Glaser over 6 years ago in reply to pragash sangaran78

TI__Guru*** 145580 points

Thanks. Your replies did come through.

Yes, it sounds like TPS63051, TPS82740, and some load switches are what you need.

0 pragash sangaran78 over 6 years ago in reply to Chris Glaser

Expert 2725 points

Dear Chris,
I’m almost there to complete my power design.

1) I will use TPS62748 instead of TPS82740 because of smaller size. TPS62748 has integrated load switch so it is perfect choice to switch between module A and B.

2) TPS63051 does not have load switch and looks like TI don’t have any parts which integrates load switch into a buck-boost converter similar to TPS63051 so I have decided to use TPS63051 without the load switch. I may add load switch if I have space to do that.

3) I have MCU without any regulator now. Since none of these regulators have battery charger, i will have to source a regulator with battery charging capability for MCU. i have some basic questions on this regulator with battery charger as below;

A) can you suggest a part for regulator + battery charger for MCU (CC2640R2F)? it will be great if the battery charger have inductive charging (wireless charging) capability. As you know, my requirement is smaller size, and low battery consumption.

B) how can I connect this regulator with battery charger for MCU? Is this regulator will supply voltage to TPS62748 and TPS63051 or is should be connected in parallel to TPS62748 and TPS63051? The accurate question is which is the most efficient way to connect? meaning most battery life saving?

I’m sorry because I’m asking a lot of question. I used TI webench designer but had some issues with it and posted questions. I’m getting your help to design my power circuit now and feel your suggestions are better than TI webench designer :)

0 pragash sangaran78 over 6 years ago in reply to pragash sangaran78

Expert 2725 points

Hi Chris,
could you please help me with my last queries as above? thanks.

0 Chris Glaser over 6 years ago in reply to pragash sangaran78

TI__Guru*** 145580 points

Hi Pragash,

I think your remaining questions are related to finding a battery charger? I have alerted that team to this post and will let them comment.

0 pragash sangaran78 over 6 years ago in reply to Chris Glaser

Expert 2725 points

Hi Chris,
i need a charger + regulator for the MCU.

BR
pragash

0 Chris Glaser over 6 years ago in reply to pragash sangaran78

TI__Guru*** 145580 points

Hi Pragash,

You can use any of the previously discussed ICs for the MCU supply.

Small chargers that I know of are the bq25100 and bq25120.

0 pragash sangaran78 over 6 years ago in reply to Chris Glaser

Expert 2725 points

hi chris,

thanks. i did use previous regulator for MCU. appreciate your help.

0 pragash sangaran78 over 6 years ago in reply to pragash sangaran78

Expert 2725 points

hi Chris,
i think bq25100 is good for as i dont need regulators anymore. i beleive the regulator you suggested earlier are more efficient than the one in bq25120.

my last question is does TI have any USB + wireless charging (inductive charging) chip in one package? if yes, its the best choice for me.

0 Bill Johns over 6 years ago in reply to pragash sangaran78

TI__Guru 68716 points

Hi Pragash
For Wireless Charging (inductive Qi standard) take a look at:
1.) The BQ51013B / 003 -- 5V supply with UBS option
2.) The BQ51050B / 51B / 52B -- Direct battery charge with USB option. But USB option is tricky.

Also see:
www.ti.com/power-management/battery-management/wireless-power/overview.html

Wireless Power Forum is read only now but WP devices are supported in the Battery Charger Forum
e2e.ti.com/.../battery_management

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WEBENCH® Tools/CC2640R2F: power supply design for my embedded system