I am trying to amplify the signal from a device with a + and - output using an ST TS4902 speaker amplifier. The problem is I do not know what to do with the - output. The datasheet for the TS4902 does not present a circuit for use with a differential device, but I know it is possible. Do I just use a duplicate circuit for the - side, duplicating the + side circuit presented in the datasheet or is something else necessary? Thanks for any help, Stu
It's a BTL amplifier configuration, which means the amplified signal is applied to one speaker terminal and an equal but inverted signal to the other terminal, quadrupling the power possible from a supply voltage. So you can't add another bridge AFAIK. One possible way is to use a transformer on the input, common for some microphone sources. Or an opamp as a differential preamp stage.
Thanks. After looking at a few datasheets and checking against a board that has the IC with the +/- outputs, it looks like the + is just grounded and the - is sent to the - input of the amp with an RC network in between. Stu
