WM8955L

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Product Preview Rev 0.4 May2003

6

Test Conditions

PARAMETER

SYMBOL

TEST CONDITIONS

MIN

TYP

MAX

UNIT

Speaker Output (LOUT2/ROUT2 with 8

Ω

Ω

Ω

Ω bridge tied load, ROUT2INV=1)

Output Power per channel

Output power is verycloselycorrelated with THD; see below.

Ω,

HPVDD=3.3V

-50

0.3

Total Harmonic Distortion

THD

Ω

HPVDD=3.3V

-40

1

dB

%

Ω

90

Signal to Noise Ratio

(A-weighted)

SNR

Ω

90

dB

Analogue Reference Levels

Midrail Reference Voltage

VMID

–3%

AVDD/2

+3%

V

Buffered Reference Voltage

VREF

–3%

AVDD/2

+3%

V

VREF source current

5mA

VREF sink current

5mA

Digital Input / Output

Input HIGH Level

0.7

×DBVDD

V

Input LOW Level

0.3

×DBVDD

V

Output HIGH Level

0.9

×DBVDD

V

Output LOW Level

0.1

×DBVDD

V

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. (No Auto-zero or Automute function is employed in achieving these results).

2.

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

Normallya THD+N measurement at 60dB below full scale. The measured signal is then corrected byadding the 60dB

to it. (e.g. THD+N @ -60dB= -32dB, DR= 92dB).

3.

THD+N (dB) - THD+N is a ratio, of the rms values, of (Noise + Distortion)/Signal.

4.

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

the other. Normallymeasured bysending a full scale signal down one channel and measuring the other.