wm9001 Wolfson Microelectronics plc, wm9001 Datasheet - Page 18

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

WM9001
THERMAL SHUTDOWN
RF NOISE SUPPRESSION
POPS / CLICK SUPPRESSION
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To protect the WM9001 from damage due to overheating, a thermal shutdown circuit is included. If
the junction temperature exceeds approximately 150ºC, then the WM9001 will be disabled.
Note that the internal power dissipation of the WM9001 is significantly higher in class AB mode than
in class D mode – see “Power De-Rating” section.
It is not possible to disable the thermal shutdown function.
The WM9001 provides internal RF filtering which minimises the impact of high frequency noise in the
system.
The WM9001 incorporates mechanisms that reduce audible pops/clicks at the speaker outputs.
To prevent pop noise, it is recommended that the BSEL, SYNC, CDMODE and INP_SEL settings
should not be modified while the speaker outputs are enabled. Muting the device (setting EN = 0)
during any update to these settings is recommended.
PP, June 2009, Rev 3.2
Pre-Production
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