wm9001 Wolfson Microelectronics plc, wm9001 Datasheet - Page 11

• Manufacturer Part Number: wm9001
• Description: 1w Dual-mode Class Ab/d Speaker Driver
• Manufacturer: Wolfson Microelectronics plc

Pre-Production
SPEAKER DRIVER PERFORMANCE
CLASS D MODE
CLASS AB MODE
w
The THD+N performance of the Speaker Driver is shown below for Class AB mode and for Class D mode.
Load R
Data is provided for four typical Power Supply /Gain combinations:
L
= 8Ω + 22μH, Frequency = 1kHz.
Figure 2 Class D Speaker Performance
Figure 3 Class AB Speaker Performance
0.001
0.001
0.01
0.01
0.1
0.1
SPKVDD=5.0V, AVDD=3.3V, Gain=3.6dB
SPKVDD=3.7V, AVDD=3.0V, Gain=2.1dB
SPKVDD=5.0V, AVDD=3.3V, Gain=3.6dB
SPKVDD=3.7V, AVDD=3.0V, Gain=2.1dB
10
10
1
1
0
0
AVDD
2.7V
3.0V
3.3V
3.3V
0.2
0.2
WM9001 THD+N Ratio v Output Power
WM9001 THD+N Ratio v Output Power
0.4
0.4
SPKVDD
0.6
2.7V
3.7V
4.2V
5.0V
Output Power (W)
Output Power (W)
0.6
Class AB
Class D
0.8
0.8
SPKVDD=4.2V, AVDD=3.3V, Gain=2.1dB
SPKVDD=2.7V, AVDD=2.7V, Gain=0dB
SPKVDD=4.2V, AVDD=3.3V, Gain=2.1dB
SPKVDD=2.7V, AVDD=2.7V, Gain=0dB
1
2.1 dB (x1.27)
2.1 dB (x1.27)
3.6 dB (x1.52)
0 dB (x1.0)
GAIN
1
1.2
1.2
1.4
1.4
1.6
PP, June 2009, Rev 3.2
WM9001
11