TDA8922C View Datasheet(PDF) - NXP Semiconductors.

Part Name

Description

Manufacturer

TDA8922C

2×75 W class-D power amplifier

NXP Semiconductors. 

NXP Semiconductors

TDA8922C

2 × 75 W class-D power amplifier

The TDA8922C single-chip Class D amplifier contains high-power switches, drivers,

timing and handshaking between the power switches, along with some control logic. To

ensure maximum system robustness, an advanced protection strategy has been

implemented to provide overvoltage, overtemperature and overcurrent protection.

Each of the two audio channels contains a PWM modulator, an analog feedback loop and

a differential input stage. The TDA8922C also contains circuits common to both channels

such as the oscillator, all reference sources, the mode interface and a digital timing

manager.

The two independent amplifier channels feature high output power, high efficiency, low

distortion and low quiescent currents. They can be connected in the following

configurations:

• Stereo Single-Ended (SE)

• Mono Bridge-Tied Load (BTL)

The amplifier system can be switched to one of three operating modes using pin MODE:

• Standby mode: featuring very low quiescent current

• Mute mode: the amplifier is operational but the audio signal at the output is

suppressed by disabling the voltage-to-current (VI) converter input stages

• Operating mode: the amplifier is fully operational, de-muted and can deliver an output

signal

A slowly rising voltage should be applied (e.g. via an RC network) to pin MODE to ensure

pop noise-free start-up. The bias-current setting of the (VI converter) input stages is

related to the voltage on the MODE pin.

In Mute mode, the bias-current setting of the VI converters is zero (VI converters are

disabled). In Operating mode, the bias current is at a maximum. The time constant

required to apply the DC output offset voltage gradually between Mute and Operating

mode levels can be generated using an RC network connected to pin MODE. An example

of a circuit for driving the MODE pin, optimized for optimal pop noise performance, is

shown in Figure 4. If the capacitor was omitted, the very short switching time constant

could result in audible pop noises being generated at start-up (depending on the DC

output offset voltage and loudspeaker used).

+5 V

5.6 kΩ

5.6 kΩ

mute/

S1

operating

470 Ω

10 µF

standby/

operating

Fig 4. Example of mode selection circuit

MODE

TDA8922C

S2

SGND

010aaa583

TDA8922C_1

Product data sheet

Rev. 01 — 7 September 2009

© NXP B.V. 2009. All rights reserved.

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