Description of Operation

1. Digital Filter

The LC78835K and 78835KM perform arithmetic functions as shown in the following block diagrams.

• Oversampling

Constructed of twice as many interpolation filters with a cascade connection arrangement using finite-impulse-

response (FIR) filters. When operating in normal-rate mode, data is transferred through a three-stage cascading

process consisting of 43rd-order, 11th-order, and third-order finite impulse response (FIR) filters connected

together to produce an eight-times oversampled signal. When operating in double-rate mode, data is transferred

through a two-stage cascading process consisting of 43rd-order and second-order finite-impulse-response (FIR)

connected filters to give a four-times oversampled signal. For further details concerning filter characteristics, refer

to page 12.

• De-emphasis

Digital de-emphasis is performed using a first-order infinite-impulse-response (IIR) filter. Filter supported

sampling frequencies include fs = 32 kHz, 44.1 kHz and 48 kHz (frequencies are all doubled with double-rate

mode).

No. 4624-6/14

LC78835K, 78835KM