FUNCTIONAL BLOCK DIAGRAM

VOLTAGE

REFERENCE

INPUT

&

DIGITAL

OFFSET

20-BIT

DAC

AD1862

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

TRIM

CLK

DATA

LE

ADJ

AGND

DGND

REV. A

Information furnished by Analog Devices is believed to be accurate and

reliable. However, no responsibility is assumed by Analog Devices for its

use, nor for any infringements of patents or other rights of third parties

which may result from its use. No license is granted by implication or

otherwise under any patent or patent rights of Analog Devices.

a

Ultralow Noise

20-Bit Audio DAC

AD1862

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

Tel: 617/329-4700

Fax: 617/326-8703

FEATURES

120 dB Signal-to-Noise Ratio

102 dB D-Range Performance

1 dB Gain Linearity

1 mA Output Current

16-Pin DIP Package

0.0012% THD + N

APPLICATIONS

High Performance Compact Disc Players

Digital Audio Amplifiers

Synthesizer Keyboards

Digital Mixing Consoles

High Resolution Signal Processing

PRODUCT DESCRIPTION

The AD1862 is a monolithic 20-bit digital audio DAC. Each

device provides a 20-bit DAC, 20-bit serial-to-parallel input

register and voltage reference. The digital portion of the

AD1862 is fabricated with CMOS logic elements that are pro-

vided by Analog Devices’ BiMOS II process. The analog por-

tion of the AD1862 is fabricated with bipolar and MOS devices

as well as thin-film resistors.

New design, layout and packaging techniques all combine to

produce extremely high performance audio playback. The de-

sign of the AD1862 incorporates a digital offset circuit which

improves low-level distortion performance. Low stress packag-

ing techniques are used to minimize stress-induced parametric

shifts. Stress-sensitive circuit elements are located in die areas

which are least affected by packaging stress. Laser-trimming of

initial linearity error affords extremely low total harmonic

distortion. Output glitch is also small, contributing to the over-

all high level of performance.

The noise performance of the AD1862 is excellent. When used

with the recommended two external noise-reduction capacitors,

it achieves 120 dB signal-to-noise ratio.

The serial input port consists of the clock, data and latch enable

pins. A serial 20-bit, 2s complement data word is clocked into

the DAC, MSB first, by the external data clock. A latch-enable

signal transfers the input word from the internal serial input

register to the DAC input register. The data clock can function

at 17 MHz, allowing 16

× F

compatible with second-generation digital filter chips for con-

sumer audio products such as the NPC SM5813 and SM5818.

The AD1862 operates with

±5 V to ±12 V supplies for the dig-

ital power supplies and

±12 V supplies for the analog supplies.

The digital and analog supplies can be separated for reduced

digital crosstalk. Separate analog and digital common pins are

also provided. The AD1862 typically dissipates less than

300 mW.

The AD1862 is packaged in a 16-pin plastic DIP. The operating

range is guaranteed to be –25

°C to +70°C.

PRODUCT HIGHLIGHTS

1. 120 dB signal-to-noise ratio. (typical)

2. 102 dB D-Range performance. (minimum)

3.

±1 dB gain linearity @ –90 dB amplitude.

4. 20-bit resolution provides 120 dB of dynamic range.

5. 16

× F

6. 0.0016% THD+N @ 0 dB signal amplitude. (typical)

7. Space saving 16-pin DIP package.

8.

±1 mA output current.

OBSOLETE