9.3.9 IV Sense

The TAS2559 provides speaker voltage and current sense for real-time monitoring of loudspeaker behavior. The VSENSE_P and VSENSE_N pins should be connected after any ferrite bead filter (or directly to the SPK_P and SPK_N connections if no EMI filter is used). The V-Sense terminals are used to eliminate IR drop error due to packaging, PCB interconnect, and ferrite bead filter resistance. The V-sense terminals are also used to close the Class-D feedback loop post filter. This Post-Filter Feedback (PFFB) minimizes the THD introduced from the filter-beads used in the system. Any interconnect resistance or non-linearities after the V-Sense terminals connection point will not be corrected for. Therefore, it is advised to connect the sense connections as close to the load as possible.

Figure 24. V-Sense Connections

The I-Sense can be configured for three ranges and shown in Table 3. This should be set appropriately based on the DC resistance of the speaker. I-Sense and V-Sense can additionally be powered down as shown in Table 4 and Table 5. When powered down, the device will return null samples for the powered down sense channels.