Ultralow Noise
20-Bit Audio DAC
a
AD1862*
FUNCTIO NAL BLO CK D IAGRAM
FEATURES
120 dB Signal-to-Noise Ratio
102 dB D-Range Perform ance
؎1 dB Gain Linearity
؎1 m A Output Current
16-Pin DIP Package
VOLTAGE
REFERENCE
+V
–V
–V
1
2
3
4
5
6
7
8
16
S
S
15 NR
S
2
0.0012% THD + N
TRIM
14
ADJ
APPLICATIONS
High Perform ance Com pact Disc Players
Digital Audio Am plifiers
Synthesizer Keyboards
Digital Mixing Consoles
+V
L
13 NR
1
CLK
LE
12
11
10
9
AGND
INPUT
&
DIGITAL
OFFSET
20-BIT
DAC
I
OUT
DATA
R
F
High Resolution Signal Processing
–V
L
DGND
AD1862
P RO D UCT D ESCRIP TIO N
register to the DAC input register. T he data clock can function
at 17 MHz, allowing 16 × FS operation. T he serial input port is
compatible with second-generation digital filter chips for con-
sumer audio products such as the NPC SM5813 and SM5818.
T he 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. T he digital portion of the
AD1862 is fabricated with CMOS logic elements that are pro-
vided by Analog Devices’ BiMOS II process. T he analog por-
tion of the AD1862 is fabricated with bipolar and MOS devices
as well as thin-film resistors.
T he AD1862 operates with ±5 V to ±12 V supplies for the dig-
ital power supplies and ±12 V supplies for the analog supplies.
T he digital and analog supplies can be separated for reduced
digital crosstalk. Separate analog and digital common pins are
also provided. T he AD1862 typically dissipates less than
300 mW.
New design, layout and packaging techniques all combine to
produce extremely high performance audio playback. T he 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.
T he AD1862 is packaged in a 16-pin plastic DIP. T he operating
range is guaranteed to be –25°C to +70°C.
P RO D UCT H IGH LIGH TS
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 × FS operation.
T he 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.
6. 0.0016% T HD+N @ 0 dB signal amplitude. (typical)
7. Space saving 16-pin DIP package.
T he 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
8. ±1 mA output current.
*P r otected by U.S. P atent Num ber s: 4,349,811; 4,857,862; 4,855,618;
3,961,326; 4,141,004; 4,902,959.
REV. A
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norw ood, MA 02062-9106, U.S.A.
Tel: 617/ 329-4700
Fax: 617/ 326-8703