LM75A
NXP
Local temperature sensor (LM75A and SE95) that monitors its own temperature
Application NoteNxp
AN10349: Digital Temperature Sensor Accuracy Explained
Explains factors affecting the accuracy of local and remote digital temperature sensors, including non-ideality factors, series resistance, and PCB layout considerations.
Overview
This application note details the various internal and external factors that influence the accuracy of digital thermal sensors. It covers the operational principles of remote sensing using the diode equation and dual current sources (I1 and I2). Key topics include the impact of the non-ideality factor on measurement error, the effects of series resistance on D+ and D- pins, and the distinction between sensor resolution and accuracy. The document specifically references NXP parts such as the LM75A, SE95, and SA56004X, explaining how to use internal offset registers to compensate for external measurement errors.
Use Cases
- CPU and FPGA temperature monitoring
- System thermal management
- Remote temperature sensing in server and card environments
- Voltage and thermal monitoring for power supplies
Topics
LM75A
SE95
SA56004X
NE1617A
NE1618
NE1619
2N3904
2N3906
digital temperature sensor
non-ideality factor
remote diode
thermal monitoring
Referenced Parts
NE1617A
NXP
Local and remote temperature sensor (SA56004X, NE1617A and NE1618)
NE1618
NXP
Local and remote temperature sensor (SA56004X, NE1617A and NE1618)
NE1619
NXP
Local and remote temperature sensor with voltage monitoring capability (NE1619)
SA56004
NXP
Fig 1. Thermal sensor with remote sensing diode ... SA56004
SA56004X
NXP
Local and remote temperature sensor (SA56004X, NE1617A and NE1618)
SE95
NXP
Local temperature sensor (LM75A and SE95) that monitors its own temperature
2N3904
NXP
discrete NPN or PNP diode connected transistor such as the 2N3904/2N3906 transistors
2N3906
NXP
discrete NPN or PNP diode connected transistor such as the 2N3904/2N3906 transistors
| LM75A | NXP | Local temperature sensor (LM75A and SE95) that monitors its own temperature |
| NE1617A | NXP | Local and remote temperature sensor (SA56004X, NE1617A and NE1618) |
| NE1618 | NXP | Local and remote temperature sensor (SA56004X, NE1617A and NE1618) |
| NE1619 | NXP | Local and remote temperature sensor with voltage monitoring capability (NE1619) |
| SA56004 | NXP | Fig 1. Thermal sensor with remote sensing diode ... SA56004 |
| SA56004X | NXP | Local and remote temperature sensor (SA56004X, NE1617A and NE1618) |
| SE95 | NXP | Local temperature sensor (LM75A and SE95) that monitors its own temperature |
| 2N3904 | NXP | discrete NPN or PNP diode connected transistor such as the 2N3904/2N3906 transistors |
| 2N3906 | NXP | discrete NPN or PNP diode connected transistor such as the 2N3904/2N3906 transistors |