SGMICRO FT2835P

The ft2835 is a charge-pump boosted Class-G/D/AB audio power amplifier with automatic level control (ALC) for portable audio applications. It integrates a Class-D/AB audio power amplifier with a Class-G charge pump regulator. With a supply voltage at 5V, it can deliver an output power of 5W with 10% THD+N, or 4.2W with 1% THD+N, into a 4Ω speaker load.

In ft2835, the power supply rail of the audio amplifier’s output stage can be adaptively boosted and regulated by a Class-G charge pump regulator, allowing higher audio loudness than a stand-alone one directly connected to the battery. The adaptive nature of the Class-G charge pump regulator’s output voltage, varying dynamically in response to the level of the audio outputs, improves power efficiency and extends battery life in playing audio. Its higher output power and greater power efficiency make ft2835 an ideal audio solution for portable applications based upon single-cell Lithium batteries.

To facilitate various applications, the charge pump regulator in ft2835 can be configured in either Adaptive Boost or Bypass mode.

Furthermore, the ft2835 provides with three types of audio amplifier outputs, i.e., Class-G, D, AB. For typical applications, Class-G/D outputs are preferred for high efficiency. Class-AB outputs are chosen specifically to alleviate design complexities for applications where minimum FM radio interference is required.

A simple one-wire pulse control is employed in ft2835 to configure the device in various operating modes.

The ft2835 features ALC that constantly monitors and safeguards the audio outputs against the amplifier’s supply voltage, preventing output clipping distortion, excessive power dissipation, or speaker over-load. Once an over-level condition is detected, the ALC lowers the amplifier’s voltage gain proportionally to eliminate output clipping.

• Wide range of supply voltages from 3V to 5.5V
• Filterless Class-D/AB audio amplifier integrated with Class-G charge pump regulator
• Automatic level control to eliminate output clipping
• One-wire pulse control to set operating mode
• Charge pump configuration: Adaptive Boost or Bypass
• Audio output configuration: Class-G/D/AB
• Low quiescent current: 3.2mA @ VDD = 3.7V
• Maximum voltage gain: 26dB
• Three ALC dynamic characteristics (sound effects)
• High SNR: 88dB (VDD = 3.7V, RL = 4Ω + 33μH, P0 = 1W)
• High efficiency: 70% (VDD = 3.7V, RL = 4Ω + 33μH, P0 = 1W)
• Low THD+N: 0.06% (VDD = 3.7V, RL = 4Ω + 33μH, P0 = 1W)
• Wide ALC dynamic range: 10dB
• Auto-recovering over-current and thermal-overload protection
• Available in TSSOP-14L package

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