9.3.11 IV Sense

The TAS2560 provides speaker voltage and current sense for real-time monitoring of loudspeaker behavior. The VSNS_P and VSNS_N pins should be connected after any ferrite bead filter (or directly to the OUT_P and OUT_N connections if no EMI filter is used). The V-Sense connections eliminate IR drop error due to packaging, PCB interconnect or ferrite bead filter resistance. The V-sense connections are also used for post filter Class-D feedback to correct for any IR-drop induced gain error or non-linearities due to the ferrite bead. It should be noted that any interconnect resistance after the V-Sense terminals will not be corrected for. Therefore, it is advised to connect the sense connections as close to the load as possible. Additionally, the v-sense pins are used the close the feedback loop on the Class-D amplifier externally. This Post-Filter Feedback (PFFB) minimized the THD introduced from the filter-beads used in the system.

Figure 31. V-Sense Connections

The I-Sense can be configured for three ranges and shown in Table 14. 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 15 and Table 16. When powered down, the device will return null samples for the powered down sense channels.