WM1824B Production Data
w
PD, Rev 4.0, November 2012
6
ELECTRICAL CHARACTERISTICS
Test Conditions
LINEVDD=AVDD=DBVDD=3.3V, LINEGND=AGND=0V, T
A
=+25
°
C, fs=48kHz, MCLK=256fs, 24-bit data, unless otherwise stated.
BCLK transition as per Figure 3.
PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT
Analogue Output Levels
Output Level
0dBFS 2.04 2.1×AVDD
3.3¯¯¯¯¯¯¯¯
2.14 Vrms
Load Impedance
1
1
k
Load Capacitance
No external RC filter 300 pF
With filter shown in
Figure 14
1 µF
DAC Performance
Signal to Noise Ratio
SNR
R
L
= 10k
A-weighted
100 106 dB
R
L
= 10k
Un-weighted
104 dB
Dynamic Range
DNR
R
L
= 10k
A-weighted
104 dB
Total Harmonic Distortion THD
-1dBFS -87 dB
0dBFS -84 dB
AVDD + LINEVDD
Power Supply Rejection Ratio
PSRR
100Hz 54 dB
1kHz 54 dB
20kHz 50 dB
Channel Separation
1kHz
100
dB
20Hz to 20kHz
95
dB
System Absolute Phase
0 degrees
Channel Level Matching
0.1 dB
Mute Attenuation
-120 dB
DC Offset at LINEVOUTL and
LINEVOUTR
<1 mV
Digital Logic Levels
Input HIGH Level
V
IH
0.7
DBVDD
V
Input LOW Level V
IL
0.3
DBVDD
V
Input Capacitance 10 pF
Input Leakage -0.9 0.9 A
Notes:
1. To prevent over-current protection shutdown of the device, ensure that the load impedance is never less than 100. If
a load impedance of less than 100 is presented to either LINEVOUTL or LINEVOUTR, the device may go into a
protective shutdown state where the charge pump will stop running and the device will shut down. It will take a
hardware reset to come out of this state (recycle the power supplies or hold /MUTE low for 1024 LRCLK cycles after
the low impedance load condition has been removed).
TERMINOLOGY
1. Signal-to-Noise Ratio (dB) – SNR is a measure of the difference in level between the maximum theoretical full scale
output signal and the output with no input signal applied.
2. Total Harmonic Distortion (dB) – THD is the level of the rms value of the sum of harmonic distortion products relative to
the amplitude of the measured output signal.
3. All performance measurements carried out with 20kHz low pass filter, and where noted an A-weighted filter. Failure to
use such a filter will result in higher THD and lower SNR readings than are found in the Electrical Characteristics. The
low pass filter removes out of band noise; although it is not audible it may affect dynamic specification values.
