MAX9746 View Datasheet(PDF) - Maxim Integrated

Part Name

Description

Manufacturer

MAX9746

1.2W, Low-EMI, Filterless, Class D Audio Amplifier

Maxim Integrated 

1.2W, Low-EMI, Filterless,

Class D Audio Amplifier

tSW

tSW

tSW

tSW

VIN-

VIN+

OUT-

OUT+

tON(MIN)

VOUT+ - VOUT-

Figure 2. MAX9746 Output with an Input Signal Applied (SSM Mode)

Filterless Modulation/Common-Mode Idle

The MAX9746 uses Maxim’s unique modulation scheme

that eliminates the LC filter required by traditional Class

D amplifiers, improving efficiency, reducing component

count, and conserving board space and system cost.

Conventional Class D amplifiers output a 50% duty-

cycle square wave when no signal is present. With no fil-

ter, the square wave appears across the load as a DC

voltage, resulting in finite load current, increasing power

consumption. When no signal is present at the input of

the MAX9746, the outputs switch as shown in Figure 3.

Because the MAX9746 drives the speaker differentially,

the two outputs cancel each other, resulting in no net

idle mode voltage across the speaker, minimizing power

consumption.

VIN = 0V

OUT-

OUT+

VOUT+ - VOUT- = 0V

Figure 3. MAX9746 Outputs with No Input Signal

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