SSM23,pdf datasheet (ADJUSTABLE CURRENT REGULATOR) (Class-D Audio Power Amplifie)

The SSM2302 is a fully integrated, high efficiency, Class-D stereo 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 5.0 V supply. It is capable of delivering 1.4 W of continuous output power with less than 1% THD + N driving an 8 Ω load from a 5.0 V supply.

The SSM2302 features a high efficiency, low noise modulation scheme. It operates with 85% efficiency at 1.4 W into 8 Ω from a 5.0 V supply and has a signal-to-noise ratio (SNR) that is better than 98 dB. PDM modulation is used to provide lower EMI-radiated emissions compared with other Class-D architectures.

The SSM2302 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 architecture of the device allows it to achieve a very low level of pop and click. 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 SSM2302 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 V_DD/2.

The SSM2302 also has excellent rejection of power supply noise, including noise caused by GSM transmission bursts and RF rectification. PSRR is typically 63 dB at 217 Hz.

The gain can be set to 6 dB or 12 dB utilizing the gain control select pin connected respectively to ground or V_DD. Gain can also be adjusted externally by using an external resistor.

The SSM2302 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, 3 mm × 3 mm lead-frame chip scale package (LFCSP).

Applications

• Mobile phones
• MP3 players
• Portable gaming
• Portable electronics
• Educational toys