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EVAL-AD1852EB

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700

World Wide Web Site: http://www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 2001

24-Bit Stereo DAC

Evaluation Board

OVERVIEW

The EVAL-AD1852-EB evaluation board permits testing and

demonstrating the high-performance AD1852 24-bit stereo

DAC. An input signal is required in either optical or coaxial

SPDIF format or, alternatively, directly via a 10-pin header in

I

header and DB-9 connector allows control of the internal regis-

ters from an external SPI controller.

Power requirements are a clean 9 V to 12 V dc source for the

digital section and a clean

±12 V dc for the analog section. The

positive supplies can be paralleled if desired. On-board regulators

derive separate “clean” 5 V dc supplies for the digital and analog

sections. Audio output is provided from two RCA phono jacks.

AD1852 OVERVIEW

The AD1852 is a complete 16-/20-/24-bit single-chip digital

audio, stereo digital-to-analog converter (DAC). It is comprised

of a multibit sigma-delta modulator with dither, continuous

time analog filters, and differential analog outputs. Other fea-

tures include an on-chip stereo attenuator, de-emphasis filter,

selectable interpolator and mute control, programmed through

FUNCTIONAL BLOCK DIAGRAM

U4

I/F

MUX

U3

DAC

AD1852

U9B

U9A

DS1

ZERO LEFT

DS2

ZERO RIGHT

J6

LEFT

J7

RIGHT

JP1

INTERPOLATION

MODE

U5

J3/J5

SPI CONTROL

PORTS

U11

S5

INTERFACE

MODE

U10

U2

DIR

DS3

DEEMPH

DS4

VERF

S1

SIGNAL

SOURCE

SELECT

U1

TOS LINK

U8

RESET

GENERATOR

RESET

S6

RESET

S2

MUTE

S4

DEEMPHASIS

S3

SPDIF/EXT(J2)

J2 EXT DATA

J1 RCA JACK

OPTICAL

INPUT

SPDIF INPUT

an SPI-compatible serial control port. The AD1852 is fully

compatible with all known DVD formats including 96 kHz and

192 kHz sample rates and 24 bits. It also is backwards-compatible

by supporting 50

µs/15 µs digital de-emphasis intended for

“redbook” Compact Discs, as well as de-emphasis at 32 kHz

and 48 kHz sample frequencies.

The AD1852 has a very simple, but very flexible, serial data

input port that allows for a glueless interconnection to a variety

of ADCs, DSP chips, digital interface receivers (DIR) and

asynchronous sample rate converters (ASRC). The AD1852

can be configured in left-justified (LJ), I

or DSP serial port compatible modes. It can support 16, 20, and

24 bits in all modes. The AD1852 accepts serial audio data in

MSB first, twos complement format. A power-down mode is

offered to minimize power consumption when the device is

inactive. The AD1852 operates from a single 5 V power supply.

It is fabricated on a single monolithic integrated circuit and

housed in a 28-lead SSOP package. Normal operation over the

temperature range 0

°C to 70°C is guaranteed.

The AD1852 data sheet gives a more complete description of

operation.