SM5844 datasheet(16/26 Pages) NPC

部品番号	SM5844

部品情報	Asynchronous Sample Rate Converter

PDF	26 Pages

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メーカー	NPC [Nippon Precision Circuits Inc]

ホームページ	http://www.npc.co.jp/en

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SM5844AF

NIPPON PRECISION CIRCUITS—16

Attenuator operation

A change in the attenuation data DATT causes the

gain to change smoothly from its previous value

towards the new setting. The new attenuation data is

stored in the attenuation data register and the current

attenuation level is stored in a temporary register.

Consequently, if a new attenuation level is read in

before the previously set level is reached, the gain

changes smoothly from the current value towards the

latest setting as shown in ﬁgure 4.

The attenuation counter output changes, and hence

the gain changes, by 1 step every output sample. The

time taken to reduce the gain from 0 dB (or 12 dB) to

−∞ dB is (1024/fso), which corresponds to

approximately 23.2 ms when fso = 44.1 kHz.

Figure 4. Attenuator operation example

Level 3

Level 1

Level 2

Level 4

Level 5

Time

Gain

∆t

0 dB

− ∞

SM5844 データシート(PDF) 16 Page - Nippon Precision Circuits Inc