• State TI Thinks Resolved
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 31 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

TPS92692: (Slope) compensation with low side sensing

J Valdez
Prodigy 30 points
Part Number: TPS92692

Hi,

(1)  For our application (VIN: 12 - 28V, VO: 40 to 80V) we want to implement low-side current sensing (CSP to LED- and CSN to GND) due to the necessity to drive different LED configuations. In the block diagram it can be seen that the TPS92692 uses adaptive slope compensation based on VIN and VCSP. In low-side sensing VSCP will be close to GND. What kind of implications will this have for the slope compensation? Can we still achieve stability with D>0.5? Our max. D will be around 0.8. Could you give us assistance on how to calculate RSLOPE if we use low-side sensing?

(2) To determine closed-loop stability we should only adapt the feedback transfer function (for the changed position of Rcs)? Are there other considerations to achieve closed-loop stabilty?

Thanks in advance.

  • 0
    TI__Mastermind 18070 points

    Hello,

    We do use VCSP and Vin as part of our peak current control so what you are doing will compromise that.  However, by lowering Rslope to about 20K you can max the slope compensation and using dominant pole feedback with 0.1uF-1uF as the compensation capacitor it can be a stable loop.  There might be some adjustments of these values but it can be designed to be stable.

    Thanks Tuan