US Patent 7859338 Compact low-power class AB amplifier

A compact low-power class AB power amplifier design is provided. In an embodiment, the amplifier design eliminates an intermediate stage that couples an input stage and a biasing mesh of the amplifier. In another embodiment, the amplifier design reuses a tail current from the input stage to bias the biasing mesh. Accordingly, a much higher power efficiency can be achieved using the proposed amplifier design compared to conventional class AB amplifiers. Further, the proposed amplifier design is extremely compact and occupies a small silicon area.