SGMICRO FT2850P

The ft2850 is a 5W Dual-PumpTM Class-AB/D/G audio power amplifier with automatic level control (ALC) for portable audio applications. It integrates Class-AB and Class-D audio power amplifiers with a Class-G charge pump regulator based upon proprietary Dual-PumpTM topology. It operates from 3.3V to 5.25V supply. With a supply voltage at 4.2V, it can deliver an output power of 5.5W with 10% THD+N, or 4.5W with 1% THD+N, into a 4Ω speaker load.

In ft2850, the power supply rail of the audio amplifier’s output stage is adaptively boosted and regulated by a Class-G charge pump regulator, allowing much higher audio loudness than a stand-alone one directly connected to the battery. The adaptive nature of the Class-G charge pump regulator, whose output voltage varies dynamically in response to the level of the audio output, improves overall power efficiency and extends battery life when playing music. The higher output power and greater power efficiency resulted from the Class-G charge pump regulator make ft2850 an ideal audio solution for battery-powered electronic devices.

To facilitate various applications, the ft2850 provides three types of audio amplifier outputs, i.e., Class-AB, Class-D, and Class-G. For typical applications, the Class-G/D audio output is preferred for its high efficiency. The Class-AB audio output can be chosen to alleviate design complexities for applications where minimum FM radio interference is required.

The ft2850 features ALC that constantly monitors and safeguards the audio output against the boosted supply voltage, preventing output clipping distortion, excessive power dissipation, or speaker over-load. Once an over-level condition is detected, the ALC lowers the voltage gain of the audio amplifier proportionally to limit the peak audio output voltage.

• Wide range of supply voltages from 3.3V to 5.25V
• Proprietary Dual-PumpTM topology
• Selectable types of audio outputs: Class-AB/D/G
• Filterless Class-D audio amplifier integrated with a Class-G charge pump regulator
• Automatic level control to eliminate output clipping
• Selectable ALC dynamic characteristics
• Selectable fade-in time
• High Efficiency: 75% (VDD = 3.7V, RL = 4Ω + 33μH, Po = 4W)
• Low THD + N: 0.04% (VDD = 3.7V, RL = 4Ω + 33μH, P0 = 2W)
• High PSRR: 70dB at 1kHz
• Maximum Voltage Gain: 28dB
• ALC dynamic range: 9dB
• Low quiescent current: 4.5mA @ VDD = 3.7V
• Auto-recovering over-current and thermal-overload protection
• Available in TSSOP-20L & QFN4X4-20L packages

• Blue Tooth Speakers
• Smart Speakers
• Portable Consumer Electronic Devices