TPS923654: TPS923652: Can TPS923652 be used for LED lighting with Vin=12V, Vout(Vf)=54V and Io=1.5A conditions?

Hi Udesh,

A single TPS923652DRRR cannot work for either of the above conditions due to the switching FET cycle-by-cycle current limit and thermal limitations.

However, you can parallel several TPS92365x devices to achieve a larger output power / output current and make it work for the above two conditions. You can refer to this E2E thread on how to do this. Also, I would recommend you use VSON package as it has the best thermal performance among the three available packages.

Best Regards,

Steven

HI Steven

Our output current requirement is around 0.7A

Below is the two conditions:

1. Vin= 12V, Vout=54V, Iout= 0.7A

2. Vin=20V, Vout=54V, Iout= 0.7A.

Kindly let us know it this part TPS923652DRRR is used for both these conditions.

Hi Udesh,

For condition 1, you cannot use TPS923652 here due to its switching FET cycle-by-cycle current limit. You can use TPS923654 / TPS923655 here. Please use VSON package here since WSON may not have enough heat-dissipation capability in this condition.

For condition 2, TPS923652DRRR can be used here if you design the inductor current ripple small enough and not trigger the switching FET cycle-by-cycle current limit. Otherwise, please also use TPS923654 / TPS923655 here. You can use either WSON or VSON package here.

Best Regards,

Steven

HI Steven

We are using the LCD display. 

Below is the specification of the LCD display.

Our Vin is 12V and for other project the Vin is 20V. So kindly let us know if this IC works for us or not.

Hi Udesh,

If possible, please provide the I-V curve of the LED for me to provide better suggestions.

Best Regards,

Steven

Hi Steven

We don have I-V curve of led. We have only this information which we have shared with you

Hi Udesh,

For Vin = 12V, V_LED = 30V, I_LED = 0.54A, you can use TPS923652 / 3 in boost connection. You should make sure the backlight unit will not light when V_LED = 12V. Otherwise, you need to use TPS923654 / 5 in buck-boost connection or you need a power-line FET to completely turn of the backlight unit.

For Vin = 20V, V_LED = 30V, I_LED = 0.54A, you can use TPS923652 / 3 in boost connection. You should make sure the backlight unit will not light when V_LED = 20V. Otherwise, you need to use TPS923652 / 3 in buck-boost connection or you need a power-line FET to completely turn of the backlight unit.

Best Regards,

Steven

HI Steven 

what is /3 here TPS923652 / 3 ?

Our have fixed input voltage of 12V and never go below 12V and output will never go below 30V.

For case 2: Our have fixed input voltage of 20V and never go below 20V and output will never go below 30V.

Hi Udesh,

Sorry for the confusion.

TPS923652 / 3 means TPS923652 or TPS923653.

TPS923654 / 5 means TPS923654 or TPS923655.

Best Regards,

Steven

HI Steven

Case 1:

Vin =12V and Vout=54V, Iout = 0.6A

Case 2:

Vin =20V and Vout=54V, Iout = 0.6A

Kindly let me know which part i need to choose.

Hi Udesh,

I am currently out of office. I will reply to you on May 6th when I am back to office. Thanks for your understanding.

Best Regards,

Steven

HI Steven 

Hope you are back now.

Can you please help to resolve my query ?

Hi Udesh,

You can refer to Section 9.2 Typical Application from the datasheet on how to design the external components and select the right part number & topology. Sorry but I do not have the time to help you check every working condition - Hope you can understand :)

If needed, I can share with you a draft-version calculation tool through e-mail.

Best Regards,

Steven

HI Steven 

Understand the problem, bit can you help me to check this last condition only ?

HI Steven 

Pleas help to share the  draft-version calculation tool through e-mail.

Hi Udesh,

I have sent you a friendship request on this E2E forum. I will send you my e-mail address through private chat after you accept the friendship request. Please contact me through e-mail and I will share with you the draft-version calculation tool.

Best Regards,

Steven

HI Steven

I accepted the friend request.

Hi Udesh,

I have sent you my e-mail address through private chat. Please contact me through e-mail. Thanks.

Best Regards,

Steven