Overview
The LM75DM-33R2, produced by onsemi, is a serially programmable temperature sensor designed to provide accurate and reliable temperature measurements. This device is part of the LM75 series and is specifically calibrated for a supply voltage of 3.3V ±5%. It features a two-wire serial interface compatible with industry-standard protocols, making it suitable for a wide range of applications requiring precise temperature monitoring.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Output Type | 2-Wire Serial | |
| Voltage - Supply | 2.7V ~ 5.5V | V |
| Resolution | 9 bits | |
| Temperature Accuracy | ±0.5°C (Typ.), ±3°C (Max.) | °C |
| Operating Temperature Range | –55°C to +125°C | °C |
| Operating Current | 250 µA (Typ.), 1.0 µA (Typ.) in Shutdown Mode | mA/µA |
| INT/CMPTR Output Sink Current | 1 - 4 mA | mA |
| Conversion Time | 55 msec | msec |
Key Features
- Temperature Sensing: Accurate temperature sensing with a typical accuracy of ±0.5°C and a maximum accuracy of ±3°C.
- Programmable Trip Point and Hysteresis: User-programmable temperature setpoint and hysteresis with default values of 80°C and 5°C hysteresis.
- Standard 2-Wire Serial Interface: Compatible with industry-standard protocols for easy communication with the host controller.
- Thermal Event Alarm Output: Functions as either a simple comparator for thermostat operation or as a temperature event interrupt.
- Shutdown Mode: Low-power standby mode to reduce power consumption.
- Multi-Zone Monitoring: Up to eight LM75 devices can share the same 2-wire bus for multi-zone temperature monitoring.
- Address Selection Inputs: Allows for multiple devices to be connected on the same bus.
- Low Power Consumption: Typical operating current of 250 µA and 1.0 µA in shutdown mode.
Applications
- Thermal Protection for High Performance CPUs: Ensures CPUs operate within safe temperature ranges.
- Solid-State Thermometer: Accurate temperature measurement in various environments.
- Fire/Heat Alarms: Reliable temperature monitoring for safety systems.
- Thermal Management in Electronic Systems: Used in computers, telecom racks, power supplies, UPS, and other electronic systems.
- Consumer Electronics and Amplifiers: Temperature monitoring in consumer electronics and audio amplifiers.
- Process Control: Precise temperature control in industrial processes.
Q & A
- What is the operating voltage range of the LM75DM-33R2?
The LM75DM-33R2 operates from 2.7V to 5.5V, with optimal performance at 3.3V ±5%.
- What is the temperature accuracy of the LM75DM-33R2?
The temperature accuracy is typically ±0.5°C and up to ±3°C over the operating temperature range.
- How does the INT/CMPTR output function?
The INT/CMPTR output can function as either a simple comparator for thermostat operation or as a temperature event interrupt. It is programmable and can be set to active-low or active-high polarity.
- Can multiple LM75 devices share the same 2-wire bus?
Yes, up to eight LM75 devices can share the same 2-wire bus for multi-zone temperature monitoring using address selection inputs).
- What is the power consumption in shutdown mode?
The power consumption in shutdown mode is typically 1.0 µA).
- What is the default setpoint and hysteresis upon power-up?
The default setpoint is 80°C with a 5°C hysteresis upon power-up).
- How is communication with the LM75DM-33R2 achieved?
Communication is achieved via a two-wire serial interface compatible with industry-standard protocols).
- What is the operating temperature range of the LM75DM-33R2?
The operating temperature range is from –55°C to +125°C).
- Can the LM75DM-33R2 be used in high-performance CPU thermal protection?
Yes, it is commonly used for thermal protection in high-performance CPUs and other electronic systems).
- How does the shutdown mode affect the device?
The shutdown mode reduces the device to a low-power standby state, significantly lowering power consumption).
