AD1859 Analog Devices, AD1859 Datasheet - Page 5

• Manufacturer Part Number: AD1859
• Description: Stereo/ Single-Supply 18-Bit Integrated DAC
• Manufacturer: Analog Devices

REV. A
DEFINITIONS
Dynamic Range
The ratio of a full-scale output signal to the integrated output
noise in the passband (0 to 20 kHz), expressed in decibels (dB).
Dynamic range is measured with a –60 dB input signal and is
equal to (S/[THD+N]) + 60 dB. Note that spurious harmonics
are below the noise with a –60 dB input, so the noise level es-
tablishes the dynamic range. This measurement technique is
consistent with the recommendations of the Audio Engineering
Society (AES17-1991) and the Electronics Industries Association
of Japan (EIAJ CP-307).
Total Harmonic Distortion + Noise (THD+N)
The ratio of the root-mean-square (rms) value of a full-scale
fundamental input signal to the rms sum of all other spectral
components in the passband, expressed in decibels (dB) and
percentage.
Passband
The region of the frequency spectrum unaffected by the attenu-
ation of the digital interpolation filter.
Passband Ripple
The peak-to-peak variation in amplitude response from equal-
amplitude input signal frequencies within the passband, ex-
pressed in decibels.
Stopband
The region of the frequency spectrum attenuated by the digi-
tal interpolation filter to the degree specified by “stopband
attenuation.”
Digital Audio Serial Input Interface
Pin Name Number
SDATA
BCLK
LRCLK
IDPM0
IDPM1
18/16
12
14
13
9
10
8
I/O
I
I
I
I
I
I
Description
Serial input, MSB first, contain-
ing two channels of 16 or 18 bits
of twos complement data per
channel.
Bit clock input for input data.
Need not run continuously; may
be gated or used in a burst
fashion.
Left/right clock input for input
data. Must run continuously.
Input serial data port mode
control zero. With IDPM1,
defines one of four serial input
modes.
Input serial data port mode con-
trol one. With IDPM0, defines
one of four serial input modes.
18-bit or 16-bit input data mode
control. Connect this signal HI
for 18-bit input mode, LO for
16-bit input mode.
PIN DESCRIPTIONS
–5–
Serial Control Port Interface
Pin Name Number
CDATA
CCLK
CLATCH
Gain Error
With a near full-scale input, the ratio of actual output to ex-
pected output, expressed as a percentage.
Interchannel Gain Mismatch
With identical near full-scale inputs, the ratio of outputs of the
two stereo channels, expressed in decibels.
Gain Drift
Change in response to a near full-scale input with a change in
temperature, expressed as parts-per-million (ppm) per C.
Crosstalk (EIAJ method)
Ratio of response on one channel with a zero input to a full-scale
1 kHz sine-wave input on the other channel, expressed in decibels.
Interchannel Phase Deviation
Difference in output sampling times between stereo channels,
expressed as a phase difference in degrees between 1 kHz inputs.
Power Supply Rejection
With zero input, signal present at the output when a 300 mV
p-p signal is applied to power supply pins, expressed in decibels
of full scale.
Group Delay
Intuitively, the time interval required for an input pulse to ap-
pear at the converter’s output, expressed in seconds (s). More
precisely, the derivative of radian phase with respect to radian
frequency at a given frequency.
Group Delay Variation
The difference in group delays at different input frequencies.
Specified as the difference between the largest and the smallest
group delays in the passband, expressed in microseconds ( s).
20
19
21
I/O
I
I
I
Description
Serial control input, MSB first,
containing 8 bits of unsigned
data per channel. Used for
specifying channel specific
attenuation and mute.
Control clock input for control
data. Control input data must
be valid on the rising edge of
CCLK. CCLK may be continu-
ous or gated.
Latch input for control data. This
input is rising edge sensitive.
AD1859