SLOSEA8 December 2024 TAS5815
PRODUCTION DATA
The TAS5815 device is often used with a low-pass filter, which is used to filter out the carrier frequency of the PWM modulated output. This filter is frequently referred to as the LC Filter, due to the presence of an inductive element L and a capacitive element C to make up the 2-pole filter.
The LC filter removes the carrier frequency, reducing electromagnetic emissions and smoothing the current waveform which is drawn from the power supply. The presence and size of the LC filter is determined by several system level constraints. In some low-power use cases that have no other circuits which are sensitive to EMI, a simple ferrite bead or a ferrite bead plus a capacitor can replace the tradition large inductor and capacitor that are commonly used. In other high-power applications, large toroid inductors are required for maximum power and film capacitors can be used due to audio characteristics. Refer to the application report Class-D LC Filter Design (SLOA119) for a detailed description on the proper component selection and design of an LC filter based upon the desired load and response.