ZHCSH28B September 2017 – December 2017 TPA3221
PRODUCTION DATA.
The output DC protection scheme protects a speaker from excess DC current in case one terminal of the speaker is connected to the amplifier while the other is accidentally shorted to the chassis ground. Such a short circuit results in a DC voltage of PVDD/2 across the speaker, which potentially can result in destructive current levels. The output DC protection detects any unbalance of the output and input current of a BTL or PBTL output configuration (current into/out of one half-bridge equals current out of/into the other half-bridge), and in the event of the unbalance exceeding a programmed threshold, the overload counter increments until its maximum value and the affected output channel is shut down. DC Speaker Protection is enabled in both BTL and PBTL mode operation.