YSF242

YSF242 (SAP2) is a digital processing LSI which performs frequency filtering and level detection necessary for spectrum analysis of the audio signals.The band frequency can be practically set up to 11 bands by software.The level data is output to the microprocessor in the decibel value through the serial interface.

There are some features of YSF242 as follows.First, level detection processing is performed on the digital data of 32K to 48KHz sampling frequency.Secondly, de-emphasis compensation is performed before the level is deteced.Thirdly, using the 2nd order IIR filter, the level detection of the bands up to seven bands and the total level detection are possible.Besides, the band frequency can be also set optionally.Furthermore, the time constant of the peak holding for level detection can be also set optionally.The sixth one is that the master clock is selected from 384fs to 256fs.The last one is 5 V or 3.3 V single power supply and Si-gate CMOS process.

What comes next is about the absolute maximum ratings of YSF242.The VDD (power supply voltage) is from -0.3 V to +0.7 V.The VIN (input voltage) is from -0.3 V to VDD+0.3 V.The Top (operating temperature) is from -40 to 85.The Tstg (storage temperature) is from -50 to +125.Then is about the recommended operating conditions.The minimum VDD (power supply voltage) is 3.0 V,the typical is 5.0 V and the maximum is 5.5 V.The minimum Top (operating temperature) is 0, the typical is 25 and the maximum is 70.

The following is about the DC characteristics of YSF242.The maximum IDD (power supply current) is 12 mA at VDD=5.5 V.The minimum VIH (input high voltage) is 0.7VDD V.The maximum VIL (input low voltage) is 0.3VDD V.The minimum VOH (output high voltage) is VDD-0.5 V V at IOH=-0.2 mA.The maximum VOL (output low voltage) is 0.4 V at IOL=0.5 mA.The minimum ILI (input leakage current) is -1A and the maximum is 1A.The minimum ILO (output leakage current) is -10A and the maximum is 10 at CDO terminal.