xref: /linux/Documentation/hwmon/lm95245.rst (revision ebf68996de0ab250c5d520eb2291ab65643e9a1e)
1Kernel driver lm95245
2=====================
3
4Supported chips:
5
6  * TI LM95235
7
8    Addresses scanned: I2C 0x18, 0x29, 0x4c
9
10    Datasheet: Publicly available at the TI website
11
12	       http://www.ti.com/lit/ds/symlink/lm95235.pdf
13
14  * TI / National Semiconductor LM95245
15
16    Addresses scanned: I2C 0x18, 0x19, 0x29, 0x4c, 0x4d
17
18    Datasheet: Publicly available at the TI website
19
20	       http://www.ti.com/lit/ds/symlink/lm95245.pdf
21
22Author: Alexander Stein <alexander.stein@systec-electronic.com>
23
24Description
25-----------
26
27LM95235 and LM95245 are 11-bit digital temperature sensors with a 2-wire System
28Management Bus (SMBus) interface and TruTherm technology that can monitor
29the temperature of a remote diode as well as its own temperature.
30The chips can be used to very accurately monitor the temperature of
31external devices such as microprocessors.
32
33All temperature values are given in millidegrees Celsius. Local temperature
34is given within a range of -127 to +127.875 degrees. Remote temperatures are
35given within a range of -127 to +255 degrees. Resolution depends on
36temperature input and range.
37
38Each sensor has its own critical limit. Additionally, there is a relative
39hysteresis value common to both critical limits. To make life easier to
40user-space applications, two absolute values are exported, one for each
41channel, but these values are of course linked. Only the local hysteresis
42can be set from user-space, and the same delta applies to the remote
43hysteresis.
44
45The lm95245 driver can change its update interval to a fixed set of values.
46It will round up to the next selectable interval. See the datasheet for exact
47values. Reading sensor values more often will do no harm, but will return
48'old' values.
49