SGMICRO FT2920P

The ft2920 is a highly efficient 7.8W boosted Class-G audio power amplifier with automatic level control (ALC) and battery tracking AGC. It integrates a filterless Class-D audio amplifier with an adaptive multi-level Class-G boost regulator and operates with a range of supply voltages from 3V to 5.5V. When a supply voltage at 3.6V, the ft2920 can deliver an output power of 7.8W with 10% THD+N, or 6.3W with 1% THD+N, into a 4Ω speaker load. In ft2920, the power supply rail of the audio amplifier’s output stage is internally boosted and regulated by an asynchronous PWM switching regulator with an integrated power switch. The boost regulator employs current-mode PWM control with proprietary multi-level operation to regulate the boosted supply voltage in response to the voltage level of the audio output. To facilitate various output power applications, three boosted supply voltage settings are available. The adaptive nature of the multi-level Class-G boost regulator improves overall efficiency. The ft2920 features ALC function to constantly monitor and safeguards the audio output against the boosted supply voltage of the audio amplifier’s output stage, preventing output clipping distortion, excessive power dissipation, and 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. In conjunction with ALC, as the battery supply voltage drops, the battery tracking AGC lowers the voltage gain of the audio amplifier to limit the peak audio output, preventing the collapse of battery voltage.

• Wide range of supply voltages from 3V to 5.5V
• Filterless Class-D audio amplifier integrated with an adaptive multi-level Class-G boost regulator
• Automatic level control to eliminate output clipping
• Battery tracking AGC to prevent battery collapse
• Soft drive mode for EMI reduction
• Three boosted voltage settings: 7.8V/7.2V/6.6V
• Maximum output power in Non-ALC mode (VBAT = 3.6V, 4Ω load, ALC = High)
• Wide ALC dynamic range: 11dB
• Three gain settings: 26dB/30dB/34dB
• High efficiency up to 82%
• Auto-recovering over-current & short-circuit protection
• Available in TSSOP-24L package

• Blue Tooth Speakers
• Portable Audio Docks
• Consumer Audio Electronics