ltc2990.rst (1880B)
1Kernel driver ltc2990 2===================== 3 4 5Supported chips: 6 7 * Linear Technology LTC2990 8 9 Prefix: 'ltc2990' 10 11 Addresses scanned: - 12 13 Datasheet: http://www.linear.com/product/ltc2990 14 15 16 17Author: 18 19 - Mike Looijmans <mike.looijmans@topic.nl> 20 - Tom Levens <tom.levens@cern.ch> 21 22 23Description 24----------- 25 26LTC2990 is a Quad I2C Voltage, Current and Temperature Monitor. 27The chip's inputs can measure 4 voltages, or two inputs together (1+2 and 3+4) 28can be combined to measure a differential voltage, which is typically used to 29measure current through a series resistor, or a temperature with an external 30diode. 31 32 33Usage Notes 34----------- 35 36This driver does not probe for PMBus devices. You will have to instantiate 37devices explicitly. 38 39 40Sysfs attributes 41---------------- 42 43============= ================================================== 44in0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V) 45temp1_input Internal chip temperature in millidegrees Celsius 46============= ================================================== 47 48A subset of the following attributes are visible, depending on the measurement 49mode of the chip. 50 51============= ========================================================== 52in[1-4]_input Voltage at V[1-4] pin in millivolt 53temp2_input External temperature sensor TR1 in millidegrees Celsius 54temp3_input External temperature sensor TR2 in millidegrees Celsius 55curr1_input Current in mA across V1-V2 assuming a 1mOhm sense resistor 56curr2_input Current in mA across V3-V4 assuming a 1mOhm sense resistor 57============= ========================================================== 58 59The "curr*_input" measurements actually report the voltage drop across the 60input pins in microvolts. This is equivalent to the current through a 1mOhm 61sense resistor. Divide the reported value by the actual sense resistor value 62in mOhm to get the actual value.