NATIONAL SEMICONDUCTOR LM81 Serial Interface ACPI-Compatible Microprocessor System Hardware Monitor handbook
Update: 29 September, 2023
The LM81 is a highly integrated data acquisition system for hardware monitoring of servers, Personal Computers, or virtually any microprocessor-based system. It can be used to monitor power supply voltages, temperatures, and fan speeds in a PC. Actual values for these inputs can be read at any time. Programmable WATCHDOG limits in the LM81 activate a fully programmable and maskable interrupt system with two outputs (INT and T_CRIT_). The LM81 has an on-chip digital output temperature sensor with 9-bit or 12-bit resolution, a 6 analog input ADC with 8-bit resolution, and an 8-bit DAC. Two fan tachometer outputs can be measured with the LM81’s FAN1 and FAN2 inputs. The DAC, with a 0 to 1.25V output voltage range, can be used for fan speed control. Additional inputs are provided for Chassis Intrusion detection circuits and VID monitor inputs. The LM81 has a Serial Bus interface that is compatible with SMBus™.
Brand: National
File format: PDF
Size: 418 KB
MD5 Checksum: 73223B6E9B485711DFFEF12C41271AA9
Publication date: 12 April, 2012
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