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TIDA-00121: Hardware changes required

Gangadhar P
Intellectual 380 points
Part Number: TIDA-00121
Other Parts Discussed in Thread: TIDA-00476

Hi,

The Design TIDA-00121.As mentioned TI,It is possible to increase the LED Drive  current up to 1.1A.

We need the LED drive current up to 2A.

Please suggest the hardware changes required for both the cases.

Thanks & Regards
Gangadhar

  • 0
    TI__Expert 3860 points

    Hi Gangadhar,

    Please take a look at TIDA-00476 for a simpler implementation. In this design, the same power stage is used for power flow in either direction. So we can get same amount of power while working as a boost converter. You may have to change the current sense resistors R11 & R12 to a lower value.

    Regards,

    Salil

  • 0 in reply to Salil
    Intellectual 380 points

    Hi Salil,

    We have TIDA-00121 working Board with us. could please suggest me the changes required in this.

    Thanks & Regards

    Gangadhar

  • 0 in reply to Gangadhar P
    TI__Expert 3860 points

    Hi Gangadhar,

    To change the current to 2A without changing the code, you need to change the current sense resistor R2 to 0.24 ohm. However, this will cause too much power loss (1W) in it. To reduce power loss, it is better to change it to a value lower than 0.1 ohm and modify the code to adjust the LED current.

    Most importantly, you should re-design the boost power stage consisting of C7, L2, Q5, D1 and C8. Q5 is sufficiently rated for this current and you need not have to change it. However, all other components should be recalculated using boost power stage design equations as described in http://www.ti.com/lit/an/slva372c/slva372c.pdf

    Regards,

    Salil