SLOS882B January 2015 – December 2017 TPA3140D2
PRODUCTION DATA.
The TPA3140D2 Thermal Foldback, TFB, is designed to protect the TPA3140D2 from excessive die temperature in case the device is operated beyond the recommended temperature or power limit, or with a weaker thermal system than recommended. The TFB works by reducing the on die power dissipation by reducing the TPA3140D2 closed loop gain in steps of 0.5 dB if the temperature trig point is exceeded. Once the die temperature drops below the TFB trig point, the TPA3140D2 closed loop gain is increased by a single or by multiple 0.5-dB steps until either the TFB trig point is reached, the closed loop gain attains the nominal closed loop gain level, or a maximum of 12-dB attenuation is reached, in which case the closed loop gain will be decreased again. The TFB gain adjustment is applied with a ramp speed selectable by the LIMRATE pin setting as shown in Table 2.