Analog Devices, Inc., has introduced what the company claims is the industry's first PDM (pulse density modulation) digital-input Class D audio amplifier for handset and other portable applications, such as portable media players and laptop computers.
The SSM2517 Class D audio amplifier combines on a single chip an audio DAC (digital-to-analogue converter), power amplifier, and a PDM digital interface. The simplified, single-chip design enables mobile device manufacturers to save BOM (bill-of-material) costs and free up board space.
The SSM2517 Class D audio amplifier combines a filterless mono Class D amplifier with an audio DAC in a tiny 1.5 mm x 1.5 mm package - the same size as some existing analogue-input Class D amplifiers. The PDM interface on the SSM2517 is the same digital interface supported by digital microphones in many handset and laptop applications. A digital interface helps to lower overall system cost, eases board layout considerations, and allows more freedom in industrial design for placement of loudspeaker transducers. Because audio is transmitted digitally to the SSM2517, the effect of GSM interference or other sources of electrically coupled noise are minimised.
The small package and filterless design means that the SSM2517 requires little board space, enabling compact designs in portable products. The integrated DAC and sigma-delta modulator architecture minimises system design challenges by mitigating EMI (electromagnetic interference). The closed-loop modulator design enables good rejection of power supply ripple and high quality audio performance. The SSM2517 is 90 percent power efficient, making it ideal for power sensitive applications.
Availability and Pricing
The SSM2517 is available now packaged in a 1.5 mm x 1.5 mm 9-ball WLCSP. Price Each Per 1,000: $0.63.