lm75.rst

  1Kernel driver lm75
  2==================
  3
  4Supported chips:
  5
  6  * National Semiconductor LM75
  7
  8    Prefix: 'lm75'
  9
 10    Addresses scanned: I2C 0x48 - 0x4f
 11
 12    Datasheet: Publicly available at the National Semiconductor website
 13
 14	       http://www.national.com/
 15
 16  * National Semiconductor LM75A
 17
 18    Prefix: 'lm75a'
 19
 20    Addresses scanned: I2C 0x48 - 0x4f
 21
 22    Datasheet: Publicly available at the National Semiconductor website
 23
 24	       http://www.national.com/
 25
 26  * Dallas Semiconductor (now Analog Devices) DS75, DS1775, DS7505
 27
 28    Prefixes: 'ds75', 'ds1775', 'ds7505'
 29
 30    Addresses scanned: none
 31
 32    Datasheets:
 33
 34	       https://www.analog.com/media/en/technical-documentation/data-sheets/DS75.pdf
 35	       https://www.analog.com/media/en/technical-documentation/data-sheets/DS1775.pdf
 36	       https://www.analog.com/media/en/technical-documentation/data-sheets/DS7505.pdf
 37
 38  * Maxim MAX6625, MAX6626, MAX31725, MAX31726
 39
 40    Prefixes: 'max6625', 'max6626', 'max31725', 'max31726'
 41
 42    Addresses scanned: none
 43
 44    Datasheets:
 45
 46	       https://www.analog.com/media/en/technical-documentation/data-sheets/MAX6625-MAX6626.pdf
 47	       https://www.analog.com/media/en/technical-documentation/data-sheets/MAX31725-MAX31726.pdf
 48
 49  * Microchip (TelCom) TCN75
 50
 51    Prefix: 'tcn75'
 52
 53    Addresses scanned: none
 54
 55    Datasheet: Publicly available at the Microchip website
 56
 57	       http://www.microchip.com/
 58
 59  * Microchip MCP9800, MCP9801, MCP9802, MCP9803
 60
 61    Prefix: 'mcp980x'
 62
 63    Addresses scanned: none
 64
 65    Datasheet: Publicly available at the Microchip website
 66
 67	       http://www.microchip.com/
 68
 69  * Analog Devices ADT75
 70
 71    Prefix: 'adt75'
 72
 73    Addresses scanned: none
 74
 75    Datasheet: Publicly available at the Analog Devices website
 76
 77	       https://www.analog.com/adt75
 78
 79  * ST Microelectronics STDS75
 80
 81    Prefix: 'stds75'
 82
 83    Addresses scanned: none
 84
 85    Datasheet: Publicly available at the ST website
 86
 87	       http://www.st.com/internet/analog/product/121769.jsp
 88
 89  * ST Microelectronics STLM75
 90
 91    Prefix: 'stlm75'
 92
 93    Addresses scanned: none
 94
 95    Datasheet: Publicly available at the ST website
 96
 97	       https://www.st.com/resource/en/datasheet/stlm75.pdf
 98
 99  * Texas Instruments TMP100, TMP101, TMP105, TMP112, TMP75, TMP75B, TMP75C, TMP175, TMP275, TMP1075
100
101    Prefixes: 'tmp100', 'tmp101', 'tmp105', 'tmp112', 'tmp175', 'tmp75', 'tmp75b', 'tmp75c', 'tmp275', 'tmp1075'
102
103    Addresses scanned: none
104
105    Datasheet: Publicly available at the Texas Instruments website
106
107	       https://www.ti.com/product/tmp100
108
109	       https://www.ti.com/product/tmp101
110
111	       https://www.ti.com/product/tmp105
112
113	       https://www.ti.com/product/tmp112
114
115	       https://www.ti.com/product/tmp75
116
117	       https://www.ti.com/product/tmp75b
118
119	       https://www.ti.com/product/tmp75c
120
121	       https://www.ti.com/product/tmp175
122
123	       https://www.ti.com/product/tmp275
124
125         https://www.ti.com/product/TMP1075
126
127  * NXP LM75B, P3T1750, P3T1755, PCT2075
128
129    Prefix: 'lm75b', 'p3t1750', 'p3t1755', 'pct2075'
130
131    Addresses scanned: none
132
133    Datasheet: Publicly available at the NXP website
134
135               https://www.nxp.com/docs/en/data-sheet/LM75B.pdf
136
137               https://www.nxp.com/docs/en/data-sheet/P3T1750DP.pdf
138
139               https://www.nxp.com/docs/en/data-sheet/P3T1755.pdf
140
141               https://www.nxp.com/docs/en/data-sheet/PCT2075.pdf
142
143  * AMS OSRAM AS6200
144
145    Prefix: 'as6200'
146
147    Addresses scanned: none
148
149    Datasheet: Publicly available at the AMS website
150
151               https://ams.com/documents/20143/36005/AS6200_DS000449_4-00.pdf
152
153Author: Frodo Looijaard <frodol@dds.nl>
154
155Description
156-----------
157
158The LM75 implements one temperature sensor. Limits can be set through the
159Overtemperature Shutdown register and Hysteresis register. Each value can be
160set and read to half-degree accuracy.
161An alarm is issued (usually to a connected LM78) when the temperature
162gets higher then the Overtemperature Shutdown value; it stays on until
163the temperature falls below the Hysteresis value.
164All temperatures are in degrees Celsius, and are guaranteed within a
165range of -55 to +125 degrees.
166
167The driver caches the values for a period varying between 1 second for the
168slowest chips and 125 ms for the fastest chips; reading it more often
169will do no harm, but will return 'old' values.
170
171The original LM75 was typically used in combination with LM78-like chips
172on PC motherboards, to measure the temperature of the processor(s). Clones
173are now used in various embedded designs.
174
175The LM75 is essentially an industry standard; there may be other
176LM75 clones not listed here, with or without various enhancements,
177that are supported. The clones are not detected by the driver, unless
178they reproduce the exact register tricks of the original LM75, and must
179therefore be instantiated explicitly. Higher resolution up to 16-bit
180is supported by this driver, other specific enhancements are not.
181
182The LM77 is not supported, contrary to what we pretended for a long time.
183Both chips are simply not compatible, value encoding differs.