UPC1851B datasheet(21/60 Pages) NEC

21 / 60 page

µPC1851B

Data Sheet S13417EJ2V0DS00

(7) Wide-band RMS Filter

A filter that limits the band width of the signal input to the wide-band RMS which controls the wide-band VCA.

The transfer function is as follows:

T(f) =

1 + j

2.09k

(8) Spectral RMS

Detects the RMS value of the signal passed through the spectral RMS filter, and converts the signal to the DC

voltage. The release time is set by adjusting the current IT of the

µPC1851B and the capacitance of the external

capacitor connected to the STI pin. The current IT is adjusted by adjusting the current from the ITI pin.

(9) Wide-band RMS

Detects the RMS value of the signal passed through the wide-band RMS filter, and converts the signal to the DC

voltage. The release time is set by adjusting the current IT of the

µPC1851B and the capacitance of the external

capacitor connected to the WTI pin. The current IT is adjusted by adjusting the current from the ITI pin.

2.4 Matrix Block

(1) Matrix

Adds L+R signal and L–R signal to output L signal, and substracts L+R signal from L–R signal to output R signal.

(2) Mode Selector

The matrix block selects the signal from the monaural signal, Stereo signal, SAP signal by the User Mode.

2.5 Selector Block

It selects the signal from the TV signal (signal with the audio multiple signal processed in the

µPC1851B) and

external input (signal input from EL1, EL2, ER1 and ER2 pins), and outputs it to the surround processor block

(surround, tone control, and volume control block).

It also selects the gain of the selection signal (0 dB/6 dB) as well as switches the stereo/monaural output (by the

I2C bus).

UPC1851B bảng dữ liệu(PDF) 21 Page - NEC