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TPS61166 for Street Light Driver Application

Amit Mane
Intellectual 500 points
Other Parts Discussed in Thread: TPS61166, TPS61500, TPS40210, TLC5960, TPS61199

 

Hi Team

One of my customer have requirement as mentioned below :

Application  : Street Light.

Project :  10W LED Driver.

Led Configuration : 3*3.

Input Voltage : from Battery Nom. 12V

Features Required :  Dimming, On/Off control based on Light Intensity( On at 1 Lux level).

Is TPS61166 suitable for this kind of requirement?

Thanks & Best Regards,

Amit Mane

 

 

  • 0
    TI__Guru**** 150950 points

    No, the TPS61166 is not the right part for this application, as it can only accept 10V on the power stage input.

    To find the right part, I need to understand your input voltage range.  i.e. how much can the battery voltage vary.

    Secondly, I need to know the forward voltage of the LEDs at the full load current.  I assume the customer wants to set the current through each 3 to around 300 mA?

    Lastly, how precise does the customer want the current in each string?  The current matching in each of the 3 strings will not be great if powered from the same voltage output of the regulator.  So, this would mean either accepting a current mismatch (and thus varying brightness) or going to 3 different ICs (one for each string) or reconfiguring the LED configuration.  For example, the TPS61500 could easily drive 9 LEDs in series at 300 mA from a 12V source.

  • 0 in reply to Chris Glaser
    Intellectual 500 points

     

    Hi Chris Glaser,

    Find more details:

     

    Input Voltage  : 12V BATTERY from the battery.

     Input Voltage Range(Battery Voltage vary) : 10.5V to 13.5V

     Forward Voltage(Vf)  of the LEDs at the full load current : Power LED with white color are used.

    The led forward we have not decided yet. It can be 350mA or 600mA or 700mA ,& will be less than 1Amp.

     Led Configuration (Row * Column ) : 3 led’s on 12V .4-5 bunches are used.

     How much precise the current required in each String(To Avoid Current Mismatching) : 1% accuracy

    Please suggest the device.

    Best Regards,

    Amit Mane

     

  • 0 in reply to Amit Mane
    TI__Guru**** 167086 points

    At present we in the dc/dc power group do not have a single IC solution for this.  For the 1% accuracy, I recommend the TPS40210 configured as a SEPIC converter to drive all the LED strings and then the TLC5960 as controller for the current sinks that pull the current through the LEDs.   We have a device in development, samples due 4Q2011, that is similar to the TPS61199 but with external current sink FETs instead of internal FETs/  Extermal current sink FETs are necessary to dissipate your power levels.  There are some other offline and dc/dc solutions here: http://focus.ti.com/lit/sg/slyt349a/slyt349a.pdf

    Our DSP group has a reference design that uses a C2000 DSP to perform both the power conversion and drive external sink FETs if you need that level of flexibility and are comfortable with software.