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National Semiconductor LM40 Hardware Monitor Datasheet
The National Semiconductor LM40 is a hardware monitor designed to measure three temperature zones and five voltage levels using a single-wire SensorPath bus interface. It features an internal local temperature sensor and two remote diode temperature sensor zones for monitoring processors or other devices. The device includes a 9-bit A/D converter with internal scaling resistors to monitor +1.2V, +2.5V, +3.3V, +5V, and +12V analog inputs.
Read onlineNational Semiconductor LM40 specifications
| Voltage Measurement Accuracy | +2 % (max) |
|---|---|
| Temperature Sensor Accuracy | +3 °C (max) |
| Operating Temperature Range | 0°C to +125°C |
| Power Supply Voltage | +3.0 V to +3.6 V |
| Average Power Supply Current | 0.5 mA (typ) |
Source: National Semiconductor LM40 Hardware Monitor Datasheet
All National Semiconductor LM40 documents by type
Ratings, dimensions and ordering codes, for selection and design work.
Questions answered in these manuals
What voltage levels can the LM40 monitor?
The device measures +1.2V, +2.5V, +3.3V, +5V and +12V analog input voltages with internal scaling resistors.
From: National Semiconductor LM40 Hardware Monitor Datasheet
How many temperature zones does the LM40 measure?
It measures three temperature zones: its own die as well as two external devices.
From: National Semiconductor LM40 Hardware Monitor Datasheet
What is the operating temperature range of the LM40?
The LM40 operates from 0 °C to +125 °C.
From: National Semiconductor LM40 Hardware Monitor with Dual Thermal Diodes SensorPath Bus Handbook
How many hardware programmable addresses does the SensorPath interface support?
It supports two hardware programmable addresses.
From: National Semiconductor LM40 Hardware Monitor with Dual Thermal Diodes SensorPath Bus Handbook