wm9090 Wolfson Microelectronics plc, wm9090 Datasheet - Page 52

• Manufacturer Part Number: wm9090
• Description: Ultra Low Power Audio Subsystem
• Manufacturer: Wolfson Microelectronics plc

WM9090
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THERMAL SHUTDOWN
SOFTWARE RESET AND CHIP ID
The WM9090 incorporates a temperature sensor which detects when the device temperature is
within normal limits or if the device is approaching a hazardous temperature condition.
The temperature status can be polled at any time by reading the TSHUT register bit. The
temperature sensor can be configured to automatically disable the audio outputs of the WM9090 in
response to an over-temperature condition (approximately 150ºC).
The temperature sensor is enabled by setting the TSHUT_ENA register bit. When the
TSHUT_OPDIS is also set, then a device over-temperature condition will cause the speaker output
(SPKOUTP and SPKOUTN) to be disabled; this response is likely to prevent any damage to the
device attributable to the large currents of the speaker output driver.
When the temperature sensor is enabled, the temperature status can be read from the TSHUT
register bit.
Note that, to prevent pops and clicks, TSHUT_ENA and TSHUT_OPDIS should only be updated
whilst the speaker and headphone outputs are disabled.
Table 33 Thermal Shutdown
A Software Reset can be commanded by writing to Register R0. This is a read-only register field and
the contents will not be affected by writing to this Register.
Table 34 Chip Reset and ID
R2 (02h)
Power
Management
(2)
R0 (00h)
Software
Reset
REGISTER
ADDRESS
REGISTER
ADDRESS
15:0
BIT
BIT
15
14
13
SW_RESET
[15:0]
TSHUT
(read only)
TSHUT_ENA
TSHUT_OPDIS
LABEL
LABEL
DEFAULT
DEFAULT
0
1
1
Writing to this register causes a
Software Reset.
Thermal shutdown status
0 = Normal temperature
1 = Over temperature
Thermal sensor enable
0 = Disabled
1 = Enabled
Thermal shutdown control
(Causes audio outputs to be disabled
if an overtemperature occurs. The
thermal sensor must also be enabled.)
0 = Disabled
1 = Enabled
DESCRIPTION
DESCRIPTION
PP, January 2010, Rev 3.0
Pre-Production
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