Our customer tries to use SSM2518CPZ as Mono only using Left speaker. Actually OUTR+- are left open.
Is it correct method?
Yes, they should leave the unused channel output pins open. They also should power down the unused channel.
Here is the explanation from the datasheet:
The left and right channels can be independently shut down by setting L_PWDN and R_PWDN (Bit 1 and Bit 2, respectively, in Register 0x09). Disabling a channel shuts down the channel specific digital processing, DAC, Class-D modulator, and power stage.
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