# LM75ADP Temperature Sensor

### Overview

The Boardoza LM75A is a precision temperature-to-digital converter module based on the highly integrated NXP LM75ADP architecture. It utilizes an on-chip bandgap temperature sensor paired with a Sigma-Delta analog-to-digital converter to deliver high-resolution thermal data.

Beyond simple measurement, the device functions as a sophisticated thermal watchdog. It includes an integrated over-temperature detection output (OS) that can operate independently as a standalone thermostat upon power-up, making it invaluable for system protection in industrial control units, power supplies, and personal computing hardware.

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|                                                              Front Side                                                              |                                                              Back Side                                                             |
| :----------------------------------------------------------------------------------------------------------------------------------: | :--------------------------------------------------------------------------------------------------------------------------------: |
| ![LM75ADP Front](https://github.com/Boardoza/Boardoza_LM75ADP_Temperature_Sensor_Breakout_Board/raw/main/assets/LM75ADP%20Front.png) | ![LM75ADP Back](https://github.com/Boardoza/Boardoza_LM75ADP_Temperature_Sensor_Breakout_Board/raw/main/assets/LM75ADP%20Back.png) |

<div align="left"><figure><img src="https://1077748559-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LuxEcL3mxZNc5Aa92N6%2Fuploads%2FewDmHJlS6eaqgiGy2okG%2FLM75ADP-1.png?alt=media&#x26;token=cd40cccf-9f0c-4678-9f2d-b848c9dbcbf0" alt="" width="375"><figcaption></figcaption></figure></div>

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### Core Technical Specifications

The module is defined by the following operational parameters:

* Sensing Architecture: On-chip bandgap sensor with an integrated 11-bit Sigma-Delta ADC.
* Resolution: Provides a fine temperature resolution of 0.125 °C, allowing for the detection of minute thermal gradients.
* Operating Voltage: Versatile supply range from 2.8 V to 5.5 V, ensuring compatibility with both low-voltage MCUs and standard 5V logic.
* Accuracy:
  * ±2 °C within the critical range of −25 °C to +100 °C.
  * ±3 °C across the extended range of −55 °C to +125 °C.
* Communication Interface: Industry-standard I2C-bus interface supporting up to 8 devices on a single bus via selectable addresses.
* Power Efficiency: Features a low-power shutdown mode consuming only 3.5 µA, ideal for battery-constrained IoT nodes.
* Robustness: ESD protection exceeding 2000 V (HBM) and latch-up immunity >100 mA, meeting strict JEDEC industrial standards.
* Physical Dimensions: Compact 20 mm x 20 mm square footprint.

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### Key Engineering Features

#### Enhanced Resolution and Compatibility

Designed as a pin-for-pin replacement for the industry-standard LM75, the LM75A offers a significant upgrade in resolution (11-bit vs 9-bit) while maintaining full backward compatibility. This allows engineers to drop it into legacy designs to instantly improve thermal tracking precision without firmware overhaul.

#### Programmable Thermal Watchdog

The module features a dedicated Overtemp Shutdown (OS) pin with programmable hysteresis and threshold set points. This open-drain output can be configured to trigger an interrupt or directly drive a cooling fan when temperatures exceed safe limits, operating entirely in hardware without constant microcontroller polling.

#### Versatile I2C Addressing

To facilitate complex sensor networks, the board supports address selection. This feature enables the simultaneous operation of up to 8 distinct LM75A modules on the same 2-wire bus, simplifying multi-point thermal monitoring in large enclosures or battery packs.

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### Hardware Interface and Signal Mapping

The module interfaces via a standard 5-pin header, supporting mixed-voltage environments:

Power and Ground

* VCC: Power supply input, accepting a wide range from 2.8V to 5.5V DC.
* GND: Common system ground.

Digital Interface

* SDA: I2C-bus bidirectional serial data line. This is an open-drain pin requiring a pull-up resistor (typically included on-board or required externally).
* SCL: I2C-bus serial clock input.
* OS (Overtemp Shutdown): Open-drain thermal alert output. Active when the measured temperature exceeds the programmed limit.

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### Applications

* System Thermal Management: Critical component monitoring for servers, routers, and base stations.
* Environmental Control: Precision thermostats for HVAC systems and office automation.
* Industrial Process Control: Over-temperature protection for motor drivers and power inverters.
* Personal Electronics: Thermal throttling logic for laptops and gaming consoles.

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### Board Dimensions:

![LM75 Temperature Sensor](https://github.com/Boardoza/Boardoza_LM75ADP_Temperature_Sensor_Breakout_Board/raw/main/assets/LM75ADP%20Dimension.png)

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{% hint style="info" %}
Ready to integrate? You can purchase the **LM75ADP Temperature Sensor** directly from our [Online Store](https://www.robotshop.com/products/acrome-lm75adp-digital-temperature-sensor-breakout-board?qd=542f89e8f2d8a10080011cc6a0c6393b). Worldwide shipping is available for engineering samples and production batches.
{% endhint %}