adt7476a Analog Devices, Inc., adt7476a Datasheet - Page 22

• Manufacturer Part Number: adt7476a
• Description: Dbcool Remote Thermal Controller And Voltage Monitor
• Manufacturer: Analog Devices, Inc.

ADT7476A
Configuration Register 2 (0x73)
[4] = 1, averaging off.
[6] = 1, single-channel convert mode.
TACH1 Minimum High Byte (0x55)
[7:5] selects ADC channel for single-channel convert mode.
Overtemperature Events
Overtemperature events on any of the temperature channels can
be detected and dealt with automatically in automatic fan speed
control mode. Register 0x6A to Register 0x6C are the THERM
temperature limits. When a temperature exceeds its THERM
temperature limit, all PWM outputs run at the maximum
PWM duty cycle (Register 0x38, Register 0x39, and Register
0x3A). This effectively runs the fans at the fastest allowed speed.
The fans run at this speed until the temperature drops below
THERM minus hysteresis. This can be disabled by setting Bit 2,
the boost bit, in Configuration Register 3 (0x78). The hysteresis
value for the THERM temperature limit is the value programmed
into the hysteresis registers (0x6D and 0x6E). The default
hysteresis value is 4°C.
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THERM can be disabled on specific temperature channels using
Bits [7:5] of Configuration Register 5 (0x7C). THERM can also
be disabled by:
•
•
THERM LIMIT
FANS
TEMPERATURE
Writing −64°C to the appropriate THERM temperature
limit in Offset 64 mode.
Writing −128°C to the appropriate THERM temperature
limit in twos complement mode.
Figure 28. THERM Temperature Limit Operation
100%
HYSTERESIS (°C)