Production Data

WM8716

WOLFSON MICROELECTRONICS LTD

PD Rev 3.1 April 2001

3

ELECTRICAL CHARACTERISTICS

TEST CONDITIONS

PARAMETER

SYMBOL

TEST CONDITIONS

MIN

TYP

MAX

UNIT

DAC Circuit Specifications

SNR (See Notes 1 and 2)

105

112

dB

THD (full-scale)

0dB FS

-92

dB

(See Note 2)

-1dB FS

-97

dB

Dynamic range

(See Note 2)

THD @ -60dB FS

105

112

dB

Filter Characteristics (Sharp Roll-off)

Passband

±0.0012 dB

0.4535fs

dB

Stopband

-3dB

0.491fs

Passband ripple

±0.0012

dB

Stopband Attenuation

f > 0.5465fs

-82

dB

Delay time

30/fs

s

Filter Characteristics (Slow Roll-off)

Passband

±0.001dB

0.274fs

Stopband

-3dB

0.459fs

Passband ripple

±0.001

dB

Stopband Attenuation

f > 0.732fs

-82

dB

Delay time

9/fs

s

Internal Analogue Filter

Bandwidth

-3dB

195

kHz

Passband edge response

20kHz

-0.043

dB

Digital Logic Levels

Input LOW level

0.8

Input HIGH level

(See Note 3)

2.0

V

Output LOW level

AVSS + 0.3V

V

Output HIGH level

AVDD - 0.3V

Notes:

1.

Ratio of output level with 1kHz full scale input, to the output level with all zeros into the digital input, measured ‘A’

weighted over a 20Hz to 20kHz bandwidth.

2.

All performance measurements done with 20kHz low pass filter. Failure to use such a filter will result in higher THD+N and

lower SNR and Dynamic Range 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.

3.

TERMINOLOGY

1.

Signal-to-noise ratio (dB) (SNR) is a measure of the difference in level between the full-scale output and the output with no

signal applied.

2.

Dynamic range (dB) (DNR) is a measure of the difference between the highest and lowest portions of a signal. Normally a

THD+N measurement at 60dB below full scale. The measured signal is then corrected by adding the 60dB to it. (eg

THD+N @ -60dB= -32dB, DR= 92dB).

3.

THD+N (dB) is a ratio of the r.m.s. values, of (Noise + Distortion)/Signal.

4.

Stop band attenuation (dB) is the degree to which the frequency spectrum is attenuated (outside audio band).

5.

Channel Separation (dB) (also known as Cross-Talk) is a measure of the amount one channel is isolated from the other.

Normally measured by sending a full-scale signal down one channel and measuring the other.

6.

Pass-Band Ripple - Any variation of the frequency response in the pass-band region.