Alan, Thank very much for the update. I'm just starting the design of a universal DAA that hopefully will meet all TBR 21 requirements.
All of the DAA circuits meet TBR 21, but I'm still a bit stymied by the holding circuit templated that requires limiting the line current to 60 mA when sourced through a 230 ohm resistor. I think the design is very close to meeting the template. I will know in next day or two. Again, thanks for the update. Regards, Duane
