2 x 2 W, Filterless, Stereo, Class-D Audio Amplifier with ALC + I2C
The SSM2380 is a fully integrated, high efficiency, stereo, Class-D audio amplifier. It is designed to maximize performance for mobile phone applications. The application circuit requires a minimum of external components and operates from a single 2.5 V to 5.5 V supply. It is capable of delivering 2 W of continuous output power with <1% THD + N driving a 4 Ω load from a 5.0 V supply.
The SSM2380 features a highly flexible I2C interface with many useful settings. Using the I2C control interface, the gain of the SSM2380 can be selected from 1 dB to 24 dB (plus mute) in 47 steps with no external components. Other features accessed from the I2C interface include independent left/right channel shutdown, variable ultralow EMI emission control mode, auto-matic level control (ALC) for high quality speaker protection, and stereo-to-mono mixing operation.
The SSM2380 features a high efficiency, low noise modulation scheme that requires no external LC output filters. The modulation continues to provide high efficiency even at low output power. The SSM2380 operates with 93% efficiency at 1.4 W into 8 Ω or with 85% efficiency at 2 W into 4 Ω from a 5.0 V supply and has an SNR of >100 dB.
Spread-spectrum pulse density modulation is used to provide lower EMI-radiated emissions compared with other Class-D architectures. An added benefit of spread-spectrum Σ-Δ modu-lation is that no synchronization (SYNC) is needed when using multiple Class-D amplifiers. For applications that require long speaker cables (>10 cm), the SSM2380 includes a user-selectable ultralow EMI emissions mode that eliminates the need for EMI filters at the Class-D outputs.
The SSM2380 has a micropower shutdown mode with a typical shutdown current of 20 nA. Shutdown is enabled by applying a logic low to the SD pin or through an optional independent channel soft shutdown via I2C.
The device also includes pop-and-click suppression circuitry. This suppression circuitry minimizes voltage glitches at the output during turn-on and turn-off, reducing audible noise on activation and deactivation.
The fully differential inputs of the SSM2380 provides excellent rejection of common-mode noise on the input. Input coupling capacitors can be omitted if the dc input common-mode voltage is approximately VDD/2.
The SSM2380 is specified over the commercial temperature range (−40°C to +85°C). It has built-in thermal shutdown and output short-circuit protection. It is available in a 16-lead, 2 mm × 2 mm wafer level chip scale package (WLCSP).
- Mobile phones
- MP3 players
- Portable electronics
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.