DSD1796DBRG4 datasheet(29/61 Pages) TI1

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DSD1796

SLES101A – DECEMBER 2003 – REVISED NOVEMBER 2006

www.ti.com

APPLICATION INFORMATION

TYPICAL CONNECTION DIAGRAM

PDATA

DSD1796

PBCK

SCK

DGND

VDD

MDI

MDO

RST

AGND2

IOUTR–

VCC1

VCOML

VCOMR

IREF

IOUTR+

AGND3R

AGND1

–

DSDL

DSDR

DBCK

PLRCK

VCC2L

AGND3L

IOUTL–

IOUTL+

DSD

Audio Data

Source

VOUT

L-Channel

5 V

VCC2R

0.1

µF

Controller

µF

3.3 V

PCM

Audio Data

Source

0.1

µF

Differential

Single

Converter

With

Low-Pass

Filter

10 k

Ω

–

VOUT

R-Channel

Differential

Single

Converter

With

Low-Pass

Filter

–

µF

5 V

µF

0.1

µF

5 V

Figure 31. Typical Application Circuit

APPLICATION CIRCUIT

The design of the application circuit is very important in order to actually realize the high S/N ratio of which the DSD1796

is capable. This is because noise and distortion that are generated in an application circuit are not negligible.

In the third-order LPF circuit of Figure 32, the output level is 2.1 V rms and 123 dB S/N is achieved.

Figure 33 shows a circuit for the DSD mode, which is a fourth-order LPF in order to reduce the out-of-band noise.

I/V Section

The current of the DSD1796 on each of the output pins (IOUTL+, IOUTL–, IOUTR+, IOUTR–) is 4 mA p-p at 0 dB (full scale).

The voltage output level of the I/V converter (Vi) is given by following equation:

Vi = 4 mA p-p

× Rf (Rf : feedback resistance of I/V converter)

An NE5534 operational amplifier is recommended for the I/V circuit to obtain the specified performance. Dynamic

performance such as the gain bandwidth, settling time, and slew rate of the operational amplifier affects the audio dynamic

performance of the I/V section.

Differential Section

The DSD1796 voltage outputs are followed by differential amplifier stages, which sum the differential signals for each

channel, creating a single-ended I/V op-amp output. In addition, the differential amplifiers provide a low-pass filter function.

The operational amplifier recommended for the differential circuit is the low-noise type.

DSD1796DBRG4 Datasheet(PDF) 29 Page - Texas Instruments

DSD1796DBRG4 Datasheet(HTML) 29 Page - Texas Instruments

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