peculiarity
Temperature sensing
6 scaling resistors positive voltage input to the display of +5 V, +12 V, +3.3 V, +2.5 V, VCCP power directly
The 8-bit DAC output controls fan speed
2. Fan speed monitoring input
Chassis burglar monitor input
Watchdog comparison of all monitored values
(LM81C) SMBus™1.0 and 1.1 (LM81B) serial bus interface compatibility
The LM81B improves voltage monitoring accuracy
VID0 - VID4 monitors the input
illustrate
The LM81 is a highly integrated data acquisition system for hardware server, PC, or virtually any microprocessor-based system for monitoring. On a PC, the LM81 can be used to monitor supply voltage, temperature, and fan speed. The actual value of these inputs can be read at any time. The LM81 programmable watchdog limits activation in a fully programmable and maskable interrupt system with two outputs (INT# and T_CRIT_#).
The LM81 has an analog input ADC with 9-bit or 12-bit resolution, 6 and 8-bit resolution, and an 8-bit DAC chip with a digital output temperature sensor. Two fan tachometer outputs measure the LM81's FAN1 and FAN2 inputs. The DAC, with an output voltage range of 0 to 1.25V, can be used for fan speed control. Provide chassis intrusion detection circuitry, and VID monitoring to invest more investment. The LM81 has an SMBus-compatible™ serial bus interface.
Main specifications
Voltage monitoring error 2% or ± 1.2% (max)
Temperature error: -40 °C to +125 °C ± 3 °C maximum
Supply voltage range 2.8V to 3.8V
Supply current 0.4 mA typical
ADC and DAC resolution 8 bits
Temperature resolution 0.5°C
apply
Thermal and hardware monitoring systems, servers and PCs
Office electronics
Electronic test equipment and instrumentation