Single-chip DDFA amplifier technology

Qualcomm® CSRA6640 is a flexible, single-chip solution which is designed to bring a new level of integration to our patented Qualcomm® DDFA™ amplifier technology.

This tight integration makes superior class-D amplification more commercially viable on smaller form factors and lower-cost products, so that manufacturers can differentiate by supporting premium sound quality in their mid-to-high-end audio products.

CSRA6640 is designed to offer multiple development advantages for premium audio performance, including reduced BOM and reduced design complexity.

Qualcomm CSRA6620 and Qualcomm DDFA are products of Qualcomm Technologies, Inc., and/or its subsidiaries.

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Product Brief

DDFA amplifier technology

DDFA digital amplifier technology is designed to combine the power advantages of class D amplifiers with the high performance of traditional linear amplifiers, engineered to perfectly balance efficiency and audio quality to help deliver a superior listening experience.


  • Highly integrated single-chip architecture with DDFA Digital PWM modulator, analog feedback processor, power management unit with single input power supply, 2x20W BTL or 1x40W PBTL output stage, and thermal protection.

  • Integrated microcontroller and OTP Memory

  • High-resolution configurable DSP with 8 channels, 2 channels out, with integrated audio mixer

  • Up to 384kHz PCM and TDM inputs, as well as DSD64/128

  • Automatic sample rate detection and conversion

  • Bass and treble crossovers and tone control

  • 15 biquad filters per channels

  • Choice of interpolation filters with different sound characters

  • Independent volume controls

  • Delay lines for driver alignment

  • Dynamic compression and soft clipping management

  • Flexible PWM configuration with 400KHz and 800Khz modulation, AD and BD modulation options

  • Cascade mode with four CSRA6640 combined for up to eight channels output sharing a single TMD bus and crystal

  • Serial control interface over SPI/I2C

  • Tuning tools for PCs


General Audio

Audio Technology: Qualcomm® DDFA™ amplifier technology

Noise floor modulation: <2dB (-60dBFS to -1dBFS)

Residual noise: < 35μVrms (AD modulation)

Signal-To-Noise Ratio: >112dB (AD 400kHz modulation, A-wt, 1kHz, 0dBFS)

Stereo Crosstalk: -103dB @ 1Khz

Audio Recording

Sampling, Record: Up to 384 KHz

Audio Playback

Playback Dynamic Range: Up to 113dB, 20Hz to 20Khz

Total Harmonic Distortion + Noise (THD+N), Playback: 20Hz to 20Khz, < 0.002%


Package Type: QFN

Pitch: 0.4mm Pitch

Package Size: 9 x 9 x 0.9 mm

    Compare related products.

    Noise floor modulationResidual noiseSignal-To-Noise RatioStereo CrosstalkPlayback Dynamic RangeTotal Harmonic Distortion + Noise (THD+N), PlaybackPackage TypePitchPackage Size
    <2dB (-60dBFS to -1dBFS)
    < 35μVrms (AD modulation)
    >112dB (AD 400kHz modulation, A-wt, 1kHz, 0dBFS)
    -103dB @ 1Khz
    Up to 113dB
    20Hz to 20Khz
    20Hz to 20Khz
    < 0.002%
    0.4mm Pitch
    9 x 9 x 0.9 mm
    <2dB (-60dBFS to 0dBFS)
    35μVrms @ 1Khz
    20Hz to 20Khz
    -103dB @ 1Khz
    Up to 113dB
    20Hz to 20Khz
    20Hz to 20Khz
    < 0.002%
    0.4mm Pitch
    9 x 9 mm

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