UAC3552A 데이터 시트보기 (PDF) - Micronas

부품명

상세내역

제조사

UAC3552A

Universal serial bus DAC

Micronas 

UAC 3552A

PRELIMINARY DATA SHEET

2.1.5.2. Analog Low-pass

The output of the DAC is filterted by an analog low-

pass filter with a cut-off frequency of approximately

1.4 MHz. This filter removes the high-frequency com-

ponents of the noise-shaping signal.

2.1.5.3. Postfilter Op Amps

This block contains the active components for the

optional analog postfilters. It is recommended to use a

second-order filter (see Section 4. “Applications” on

page 26) in order to attenuate the out-of-band noise

caused by the noise shaper The op amps and all I/O-

pins for this block are shown in Fig. 2–2.

2.1.5.4. Input Mixer

This block is used to mix the auxiliary inputs and the

signals coming from the DAC. This allows to use an

UAC 3552A-based USB speaker in a non-USB envi-

ronment, like WIN 3.11 or other operating systems. On

the other hand, it allows to connect additional analog

sources, like CD-player or Walkman even while the

speaker is connected to the USB. The input mixer is

hardware-controlled by the AUXEN pin.

Table 2–1: AUXEN pin

AUXEN

0

1

AUX not selected

AUX selected

This allows to use a jack that switches the AUXEN to

low when an analog source is plugged in, according to

the application note Section 4. “Applications” on page

26. The DAC-signal is permanently connected to the

mixer because the DAC is extremely quiet if no USB

audio is applied.

The AUXEN pin also keeps the UAC 3552A from

entering the low-power mode when an analog source

is connected. Please note that in this mode, the

UAC 3552A is not USB-compliant. If the USB is not

connected the GPIO pins work as an USB-indepen-

dent volume control (see Table 2–2). BassBoost is not

supported in this mode.

For external components,

see section “Applications”

UAC 3552A (Back-end)

FOUTL

from switch matrix

AVSS VREF AGNDC

FOUTR

FOPL

−

FINL

Analog Vol. L

−

−

FOPR

−

Analog Vol. R

FINR

For external components,

see section “Applications”

Fig. 2–2: Postfilter op amps and analog volume

8

OUTL

OUTR

Micronas

Share Link: