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Features
SensorPath Interface
2 hardware programmable addresses
Voltage Monitoring
9-bit ΣΔ ADC
Internal scaling resistors for all inputs
Monitors +1.2V, +2.5 V, +3.3 V, +5 V and +12 V
Temperature Sensing
2 remote diode temperature sensor zones
Internal local temperature zone
0.5 °C resolution
Measures temperatures up to 140 °C
14-lead TSSOP package
Description The
LM40 is a hardware monitor that measures 3 temperature zones, 5 voltages and has a single-wire interface compatible with SensorPath
bus. SensorPath data is pulse width encoded, thereby allowing the
LM40 to be easily connected to many general purpose micro-controllers. Several Winbond Electronic Super I/O products include a
fully integrated SensorPath master, that when connected to the
LM40 can realize a hardware monitor function that includes limit checking for measured values, autonomous fan speed control and
many other functions.
The
LM40 measures the temperature of its own die as well as two external devices such as a processor thermal diode or a diode connected
transistor. The
LM40 can resolve temperatures up to 255°C and down to -256°C. The operating temperature range of the
LM40 is 0°C to +125°C. Using ΣΔ ADC it measures +1.2V, +2.5V, +3.3V, +5V and +12V analog input voltages with internal scaling
resistors.The address programming pin allows two
LM40s to be placed on one SensorPath bus.
Key Specification
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Voltage Measurement Accuracy
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±2 % (max)
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Temperature Sensor Accuracy
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±3 °C (max)
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Temperature Range:
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LM40 junction
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0 °C to +85 °C
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Remote Temp Accuracy
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0 °C to +100 °C
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Power Supply Voltage
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+3.0 V to +3.6 V
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Average Power Supply Current
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0.5 mA (typ)
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Conversion Time (all Channels)
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29.6ms to 1456ms
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Applications
Microprocessor based equipment
(Motherboards, Video Cards, Base-stations, Routers, ATMs, Point of Sale, …)
Power Supplies
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