28bit Audio DSP with Built-in 2ch ADC, 6ch DAC, and ASRC - BU9406KS2

This LSI is the digital sound processor which made the use digital signal processing for FPD TVs.
DSP of ROHM original is used for the TV sound processor unit, and it excels in cost performance.
The asynchronous sampling rate converter is built in the digital input one line. The audio AD converter is built inthe analog input one line. The audio DA converters are built in the output three lines.

* This product is a STANDARD grade product and not recommend for on-vehicle devices.
Part number
Unit Quantity
Minimum Package Quantity
Packing Type
BU9406KS2 Active SQFP-T80C 500 50 Tray Yes
Vcc(Min.)[V] 3.0
Vcc(Max.)[V] 3.6
Iq[mA] 60.0
I/F 2 wire port
Digital Audio I/F I2S SPDIF
Additional Feature P²Bass, P²Treble, 12band P-EQ, Surround
Number of ADCs 2
Number of DACs 6
Sampling Rate(Max.)[kHz] 48
ADC SNR(Typ.)[dB] 90
ADC THD+N[%] 0.02
DAC SNR(Typ.)[dB] 96
DAC THD+N[%] 0.0050
Multi Input Stereo 4
Volume Range +6to-121 dB
Volume Step 0.5
Tone Control Band 12 Band P-EQ
Operating Temperature (Min.)[°C] -40
Operating Temperature (Max.)[°C] 85
  • ・ Digital Signal Processor unit Word length: 28bit (Data RAM) The fastest machine Cycle: 40.7ns (512fs, fs=48kHz) Multiplier: 28x24 → 52 bit Adder: 28+28 → 28bit Data RAM: 256x28bit Coefficient RAM: 128x24bit Sampling Frequency: fs=48kHz Master Clock: 512fs (24.576Mhz, fs=48kHz)
    ・ Digital Signal Input (Stereo 4 lines): 16/20/24bit (I2S, Left-Justified, Right-Justified) Digital Signal Output (Stereo 4 lines): 16/20/24bit (I2S, Left-Justified, Right-Justified, S/PDIF)
    ・ Asynchronous Sampling Rate Converter (Stereo 1 line): 32kHz/44.1kHz → 48kHz
    ・ Audio ADC: Stereo Input 1 line 20bit 64 x Over-sampling sigma delta ADC S/N: 90dB THD+N: 0.02% (Sine-wave 1kHz, -0.5dB) Digital HPF (fc=1Hz)
    ・ Audio DAC: Stereo Output 2 lines 24bit 8x Over-sampling digital filter + 1bit sigma delta DAC S/N: 96dB THD+N: 0.005% (Sine-wave 1kHz, 0dB)
    ・ Audio 16bit DAC: Stereo Output 1 line 24bit 8x Over-sampling digital filter + Audio 16bit DAC S/N: 90dB THD+N: 0.03% (Sine-wave 1kHz, 0dB)
    ・ The sound signal processing function for FPD TVs Pre-scaler, Channel Mixer, Pseudo Stereo, Surround, P2Bass, SAS,12-band parametric EQ, Master Volume, L/R Balance, Compression, Post-scaler, Output Signal Clipper (P2Bass and SAS are ROHM’s own sound effect functions.)
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Technical Data
Application Note

Thermal Resistance