SSM2317

滤波的高效单声道3瓦D类音频放大器 Filterless High Efficiency Mono 3 W Class-D Audio Amplifier

Product Details

The is a fully integrated, high efficiency, 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 3 W of continuous output power with <1% THD + N driving a 3 Ω load from a 5.0 V supply.

The SSM2317 features a high efficiency, low noise modulation scheme that does not require any external LC output filters. The modulation continues to provide high efficiency even at low output power. It operates with 93% efficiency at 1.4 W into 8 Ω or 85% efficiency at 3 W into 3 Ω from a 5.0 V supply and has an SNR of >93 dB. Spread-spectrum pulse density modulation is used to provide lower EMI radiated emissions compared with other Class-D architectures.

Automatic level control ALC can be activated to suppress clipping and improve dynamic range. This feature only requires one external resistor tied to GND via the VTH pin and an activation voltage on the ALC_EN pin.

The SSM2317 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.

The device also includes pop-and-click suppression circuitry. This minimizes voltage glitches at the output during turn-on and turn-off, reducing audible noise on activation and deactivation.

The default gain of the SSM2317 is 18 dB, but users can reduce the gain by using a pair of external resistors.

The SSM2317 is specified over the commercial temperature range of −40°C to +85°C. It has built-in thermal shutdown and output short-circuit protection. It is available in a 9-ball, 1.5 mm × 1.5 mm wafer level chip scale package WLCSP.

**Applications**

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Mobile phones

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MP3 players

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Portable gaming

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Portable electronics

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Educational toys

### Features and Benefits

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Filterless Class-D amplifier with Σ-Δ modulation

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Automatic level control ALC improves dynamic range and prevents clipping

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3 W into 3 Ω load and 1.4 W into 8 Ω load at 5.0 V supply with <10% total harmonic distortion ALC off

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700 mW into 8 Ω load at 4.2 V supply ALC 80%

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93% efficiency at 5.0 V, 1.4 W into 8 Ω speaker

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>93 dB signal-to-noise ratio SNR

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Single-supply operation from 2.5 V to 5.5 V

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20 nA ultralow shutdown current

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Short-circuit and thermal protection

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Available in 9-ball, 1.5 mm × 1.5 mm WLCSP

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Pop-and-click suppression

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Built-in resistors reduce board component count

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Default fixed 18 dB or user-adjustable gain setting