SSM2305 Datasheet | Analog Devices

Filterless High Efficiency Mono 2.8 W Class-D Audio Amplifier SSM2305 Features Filterless Class-D amplifier with Σ-Δ modulation No sync necessary when using multiple Class-D amplifiers from Analog Devices, Inc. 2.8 W into 4 Ω load and 1.6 W into 8 Ω load at 5.0 V supply with <10% total harmonic distortion (THD) 89% efficiency at 5.0 V, 1.3 W into 8 Ω speaker >98 d B signal-to-noise ratio (SNR) Single-supply operation from 2.5 V to 5.5 V 20 n A ultralow shutdown current Short-circuit and thermal protection Available in 8-lead, 3 mm × 3 mm LFCSP and MSOP Pop-and-click suppression Built-in resistors reduce board ponent count Fixed and user-adjustable gain configurations The SSM2305 Features a high efficiency, low noise modulation scheme that does not require external LC output filters. The modulation provides high efficiency even at low output power. The SSM2305 operates with 90% efficiency at 1.3 W into 8 Ω or 83% efficiency at 2.2 W into 4 Ω from a 5.0 V supply and has an SNR of >98 d B. Spread-spectrum pulse density modulation is used to provide lower EMI-radiated emissions pared with other Class-D architectures. The SSM2305 has a micropower shutdown mode with a maximum shutdown current of 30 n A. Shutdown is enabled by applying a Logic 0 to the SD pin. The device also includes pop-and-click suppression circuitry. This minimizes voltage glitches at the output during turn-on and turn-off, thus reducing audible noise on activation and deactivation. The fully differential input of the SSM2305 provides excellent rejection of mon-mode noise on the input. Input coupling capacitors can be omitted if the dc input mon-mode voltage is approximately VDD/2. The SSM2305 has excellent rejection of power supply noise, including noise caused by GSM transmission bursts and RF rectification. PSRR is typically 60 d B at 217 Hz. The default gain of the SSM2305 is 18 d B, but users can reduce the gain by using a pair of external resistors. The SSM2305 is specified over the...