The Thermal Foldback (TFB) is designed to protect TAS5828M from excessive die temperature increases, in case the device operates beyond the recommended temperature/power limit, or with a weaker thermal system design than recommended. It allows the TAS5828M to play as loud as possible without triggering unexpected thermal shutdown. When the die temperature triggers the over-temperature warning (OTW) level (TAS5828M has four different temperature threshold, each threshold is indicated in I²C register 0x73 bits 0,1,2 and 3 ), an internal AGL (Automatic Gain Limiter) reduces the digital gain gradually, lower value of OTW, smaller attenuation added, with the OTW waring goes higher, more attenuation added. Once the die temperature drops below the OTW, the device’s digital gain gradually returns to the former setting. Both the attenuation gain and adjustable rate are programmable. The TFB gain regulation speed (attack rate and release rate) settings are the same as a regular AGL, which is also configurable with TAS5828M App in PurePathTM Console3.