WM8959 Wolfson Microelectronics Ltd., WM8959 Datasheet - Page 22

• Manufacturer Part Number: WM8959
• Description: Mobile Multimedia DAC with Dual-mode Class AB/D Speaker Driver
• Manufacturer: Wolfson Microelectronics Ltd.

WM8959
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SPEAKER DRIVER PERFORMANCE
HEADPHONE DRIVER PERFORMANCE
0.001
0.01
0.01
0.1
10
0.1
10
1
1
0
0
Typical speaker driver THD+N performance is shown below for both Class D and Class AB modes. Curves are shown for
four typical SPKVDD supply voltage and gain combinations.
Load R
Typical THD+N performance of the Headphone Drivers is shown below (AC coupled to LOUT/ROUT). Curves are shown
for four HPVDD/AVDD supply voltages.
Load R
AC COUPLED HEADPHONE INTO 16Ω
SPEAKER CLASS D INTO 8Ω + 10µH
10
0.25
L
L
= 8Ω + 10µH, Frequency = 1kHz, +1dB gain in active path.
= 16Ω and 32Ω, Frequency = 1kHz, +1dB gain in active path.
20
AC Coupled Headphone (16ohm)
Speaker Class D (8Ω+10µH)
THD+N Ratio v Output Power
THD+N Ratio v Output Power
0.5
30
Output Power (mW)
Output Power (W)
0.75
40
50
1
SPKVDD=5.0V, AC=DC=1.52x
SPKVDD=4.2V, AC=DC=1.27x
SPKVDD=3.6V, AC=DC=1.00x
SPKVDD=3.3V, AC=DC=1.00x
60
HPVDD=AVDD=3.6V
HPVDD=AVDD=3.3V
HPVDD=AVDD=3.0V
HPVDD=AVDD=2.7V
1.25
70
1.5
80
0.01
0.001
0.1
0.01
10
0.1
1
10
1
0
0
SPEAKER CLASS AB INTO 8Ω + 10µH
AC COUPLED HEADPHONE INTO 32Ω
10
0.25
20
AC Coupled Headphone (32ohm)
Speaker Class AB (8Ω+10µH)
THD+N Ratio v Output Power
THD+N Ratio v Output Power
0.5
30
Output Power (mW)
Output Power (W)
0.75
40
PP, May 2008, Rev 3.1
50
SPKVDD=5.0V, AC=DC=1.52x
SPKVDD=4.2V, AC=DC=1.27x
SPKVDD=3.6V, AC=DC=1.00x
SPKVDD=3.3V, AC=DC=1.00x
1
60
Pre-Production
HPVDD=AVDD=3.6V
HPVDD=AVDD=3.3V
HPVDD=AVDD=3.0V
HPVDD=AVDD=2.7V
1.25
70
1.5
22
80