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TMS320F2800157-Q1: Up down dual ramp generation by CMPSS module

Part Number: TMS320F2800157-Q1

Hello,

Can we generated dual up - down ramp with CMPSS module of 157 controller. (simultaneously positive and negative slope ramp or one cycle of ramp consist of positive and negative slope ramp(half cycle each)).

If 157 controller does not provide this feature, please suggest controllers with this feature.

Any TI application note using dual up down ramp would be great help.

Regards,

  • Hello Jay,

    The Ramp Generator (H) and Ramp Generator (L) on the CMPSS module can be configured either up-mode or down-mode. So, you can simultaneously get positive slope ramp in Ramp Generator (H) and negative slope ramp in Ramp Generator (L).

    Regards,

    Hadi

  • Hello Hadi,

    Thanks for the response.

    Actually I am taking case within single comparator only (either H or L). (Definitely we can create up ramp in H comp and down ramp in L comp, but what I am looking is, whether this controller or any other TI  controller can generate up down (triangle type ramp) within single comparator only as shown in the image below.

    Image 1: one ramp cycle consist of up and down ramp half cycle each
    Image 2: Up down ramp both generated by controller, based on positive or negative quantity on other comparator positive pin, it will match with either up or down ramp, and comparator output would be 1.

    Pls suggest. 

    Regards,

  • Hello Jay,

    Unfortunately this function is not available in CMPSS module of any C2000 devices right now. However, with help of the DMA module, you can repeatedly send the DAC values from a look-up vector that contains the customized ramp.

    Regards,

    Hadi