Documentation/hwmon/max31827.rst

1 .. SPDX-License-Identifier: GPL-2.0
12     Addresses scanned: I2C 0x40 - 0x5f
20     Addresses scanned: I2C 0x40 - 0x5f
28     Addresses scanned: I2C 0x40 - 0x5f
34 	- Daniel Matyas <daniel.matyas@analog.com>
37 -----------
40 between them is found in the default power-on behaviour of the chips. While the
48 MAX31827 implements a temperature sensor with a 6 WLP packaging scheme. This
49 sensor measures the temperature of the chip itself.
51 MAX31827 has low and over temperature alarms with an effective value and a
52 hysteresis value: -40 and -30 degrees for under temperature alarm and +100 and
53 +90 degrees for over temperature alarm.
55 The alarm can be configured in comparator and interrupt mode. Currently only
56 comparator mode is implemented. In Comparator mode, the OT/UT status bits have a
57 value of 1 when the temperature rises above the TH value or falls below TL,
59 the temperature drops below the TH_HYST value or when shutdown mode is entered.
60 Similarly, UT status returns to 0 when the temperature rises above TL_HYST value
61 or when shutdown mode is entered.
63 Putting the MAX31827 into shutdown mode also resets the OT/UT status bits. Note
64 that if the mode is changed while OT/UT status bits are set, an OT/UT status
67 clear the status bits before changing the operating mode.
69 The conversions can be manual with the one-shot functionality and automatic with
75 (default) 140ms. When chip is in shutdown mode and a read operation is
76 requested, one-shot is triggered, the device waits for 140 (conversion time) + 1
77 (error) ms, and only after that is the temperature value register read.
79 The LSB of the temperature values is 0.0625 degrees Celsius, but the values of
80 the temperatures are displayed in milli-degrees. This means, that some data is
82 in the writing of alarm values too. For positive numbers the user-input value
84 the user-input will always be rounded up to the nearest possible value.
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