lm95234.rst 1.7 KB

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  1. Kernel driver lm95234
  2. =====================
  3. Supported chips:
  4. * National Semiconductor / Texas Instruments LM95233
  5. Addresses scanned: I2C 0x18, 0x2a, 0x2b
  6. Datasheet: Publicly available at the Texas Instruments website
  7. https://www.ti.com/product/lm95233
  8. * National Semiconductor / Texas Instruments LM95234
  9. Addresses scanned: I2C 0x18, 0x4d, 0x4e
  10. Datasheet: Publicly available at the Texas Instruments website
  11. https://www.ti.com/product/lm95234
  12. Author: Guenter Roeck <linux@roeck-us.net>
  13. Description
  14. -----------
  15. LM95233 and LM95234 are 11-bit digital temperature sensors with a 2-wire
  16. System Management Bus (SMBus) interface and TrueTherm technology
  17. that can very accurately monitor the temperature of two (LM95233)
  18. or four (LM95234) remote diodes as well as its own temperature.
  19. The remote diodes can be external devices such as microprocessors,
  20. graphics processors or diode-connected 2N3904s. The chip's TruTherm
  21. beta compensation technology allows sensing of 90 nm or 65 nm process
  22. thermal diodes accurately.
  23. All temperature values are given in millidegrees Celsius. Temperature
  24. is provided within a range of -127 to +255 degrees (+127.875 degrees for
  25. the internal sensor). Resolution depends on temperature input and range.
  26. Each sensor has its own maximum limit, but the hysteresis is common to all
  27. channels. The hysteresis is configurable with the tem1_max_hyst attribute and
  28. affects the hysteresis on all channels. The first two external sensors also
  29. have a critical limit.
  30. The lm95234 driver can change its update interval to a fixed set of values.
  31. It will round up to the next selectable interval. See the datasheet for exact
  32. values. Reading sensor values more often will do no harm, but will return
  33. 'old' values.