a
Ultralow Noise
20-Bit Audio DAC
AD1862
FUNCTIONAL BLOCK DIAGRAM
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
16 +VS
2
15 NR2
TRIM 3
OBS
1
–VS
APPLICATIONS
High Performance Compact Disc Players
Digital Audio Amplifiers
Synthesizer Keyboards
Digital Mixing Consoles
High Resolution Signal Processing
PRODUCT DESCRIPTION
VOLTAGE
REFERENCE
–VS
14 ADJ
+VL 4
13 NR1
CLK 5
LE 6
DATA 7
12 AGND
INPUT
&
DIGITAL
OFFSET
20-BIT
DAC
10 RF
OLE
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 provided by Analog Devices’ BiMOS II process. The analog portion 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 design of the AD1862 incorporates a digital offset circuit which
improves low-level distortion performance. Low stress packaging 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 overall high level of performance.
–VL 8
11 IOUT
9
AD1862
DGND
TE
register to the DAC input register. The data clock can function
at 17 MHz, allowing 16 × FS operation. The serial input port is
compatible with second-generation digital filter chips for consumer audio products such as the NPC SM5813 and SM5818.
The AD1862 operates with ± 5 V to ± 12 V supplies for the digital 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.
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.
4. 20-bit resolution provides 120 dB of dynamic range.
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
6. 0.0016% THD+N @ 0 dB signal amplitude. (typical)
5. 16 × FS operation.
7. Space saving 16-pin DIP package.
8. ± 1 mA output current.
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
