GENERAL DESCRIPTION

The SGM4700 is a high-power, high efficiency, stereo Class-D audio power amplifier with adjustable power limit

APL) and automatic level control (ALC). It operates with a wide range of supply voltages from 5V to 20V. With 15V supply voltage, it can deliver 2 × 23W output power for a pair of 4Ω speakers with 1% THD+N, or an ALC output power of 2 × 20W with THD+N less than 0.5%.

The high efficiency of SGM4700 extends battery life in playing music and allows it to deliver an output power of 2 × 20W without the need for a bulky heat sink on a two-layer system board. Its high PSRR and low EMI emission reduce system design and manufacturing complexities, as well as lower system cost.

The SGM4700 features APL and ALC. The APL limits peak audio outputs to a user-defined value to protect audio speakers from excessive power dissipation or over-load. The APL and ALC adjust the voltage gain of the audio amplifiers in response to over-limit audio inputs, eliminating output clipping distortion while maintaining a maximally allowed dynamic range of audio outputs. The limiting voltage of APL and ALC can be either a user-defined value or the supply voltage.

The SGM4700 can be configured into driving either a pair of speakers in Bridge-Tied-Load (BTL) configuration for stereo applications or a single speaker in Parallel BTL (PBTL) configuration for mono applications.

The SGM4700 features two PWM modulation schemes for Class-D audio amplifiers: Dual-Side-Modulation (DSM) and Single-Side-Modulation (SSM).

In SGM4700, comprehensive protection modes against various operating faults ensure its safe and reliable operation.

FEATURES

● Wide Range of Supply Voltages from 5V to 20V

● Adjustable Power Limit to Safeguard Audio Speakers

● Automatic Level Control to Eliminate Output Clipping

● 4 Selectable Gain Settings: 20/26/30/34dB

● 3 Selectable ALC Dynamic Characteristics

● 2 Selectable PWM Frequencies with Optional Spread-Spectrum: 360kHz and 500kHz

● 2 Selectable Modulation Schemes: SSM and DSM

● Optional PBTL Configuration for Mono Applications

● Maximum Output Power (THD+N = 1%) in Non-ALC

 2 × 32W (VDD = 18V, 4Ω + 33μH, BTL)

 2 × 18W (VDD = 18V, 8Ω + 33μH, BTL)

 33W (VDD = 15V, 3Ω + 15μH, PBTL)

● Maximum Output Power (THD+N < 0.5%) in ALC

 2 × 29W (VDD = 18V, 4Ω + 33μH, BTL)

 2 × 16W (VDD = 18V, 8Ω + 33μH, BTL)

 30W (VDD = 15V, 3Ω + 15μH, PBTL)

● Wide ALC Dynamic Range: 12dB (VDD = 12V)

● Low THD+N: 0.02% (VDD = 12V, 4Ω + 33μH, PO = 10W/CH)

● High PSRR: 80dB at 1kHz with SSM

● Protection Modes against Various Operating Faults Including Under-Voltage, Over-Voltage, Over-Current, Over-Temperature and DC-Detect

● Available in a Green TSSOP-28 (Exposed Pad) Package

APPLICATIONS

Bluetooth/Wireless Speakers

Consumer Audio Speakers

Soundbars