LM35DZ

LM35DZ Precision Centigrade Temperature Sensor

Overview

The LM35DZ is a precision integrated-circuit temperature sensor that provides an output voltage linearly proportional to the Celsius (Centigrade) temperature. Unlike sensors calibrated in Kelvin, the LM35DZ eliminates the need for subtracting a large constant voltage from its output, simplifying direct Centigrade temperature measurements. This device is factory-calibrated to deliver high accuracy without requiring additional trimming or external calibration. Its low output impedance, linear response, and ease of interfacing make it ideal for a wide range of temperature-sensing applications.

The LM35DZ operates over a temperature range of -55°C to +150°C, with typical accuracies of ±¼°C at room temperature and ±¾°C across the full range. Its low power consumption (60 µA) ensures minimal self-heating, contributing to measurement accuracy. The sensor is available in a TO-92 plastic package, making it cost-effective and easy to integrate into various circuits.

Features

• Direct Celsius Calibration: Output voltage is directly proportional to °C, eliminating the need for conversion.
• High Accuracy: ±¼°C typical accuracy at room temperature (±¾°C over full range).
• Low Self-Heating: Draws only 60 µA, resulting in less than 0.1°C self-heating in still air.
• Wide Operating Range: -55°C to +150°C temperature range.
• Linear Output: 10 mV/°C scale factor for straightforward analog-to-digital conversion.
• Low Output Impedance: 0.1 Ω for easy interfacing with readout or control circuits.
• Single or Dual Supply Operation: Compatible with single power supplies (4V–30V) or dual supplies (±2V–±15V).
• No External Calibration Required: Factory-trimmed for precision.
• Cost-Effective Packaging: Available in TO-92 plastic package for easy PCB mounting.

Applications

The LM35DZ is widely used in applications requiring precise temperature monitoring and control, including:

• Thermostats and Climate Control Systems: Provides accurate ambient temperature feedback.
• Industrial Process Monitoring: Ensures stable temperature conditions in manufacturing.
• Consumer Electronics: Used in devices like laptops and smartphones for thermal management.
• Automotive Systems: Monitors engine and cabin temperatures.
• Medical Equipment: Ensures safe operating temperatures in diagnostic and therapeutic devices.
• HVAC Systems: Facilitates energy-efficient heating and cooling.
• Battery Management: Prevents overheating in rechargeable battery packs.
• Scientific Instrumentation: Provides reliable temperature data in lab equipment.

Electrical Characteristics

The following table summarizes the key electrical specifications of the LM35DZ:

• Supply Voltage Range: 4V to 30V (single supply) or ±2V to ±15V (dual supply).
• Output Voltage Range: -550 mV (-55°C) to +1500 mV (+150°C).
• Scale Factor: 10 mV/°C.
• Current Consumption: 60 µA (typical).
• Output Impedance: 0.1 Ω (typical).
• Non-Linearity: ±¼°C (typical) at room temperature.
• Operating Temperature Range: -55°C to +150°C.

Package Information

The LM35DZ is available in a TO-92 plastic package, which is compact and suitable for through-hole PCB mounting. Key package details include:

• Package Type: TO-92 (3-pin).
• Pin Configuration:
  • Pin 1: V_CC (Supply Voltage).
  • Pin 2: V_OUT (Analog Output).
  • Pin 3: GND (Ground).
• Dimensions: 4.95 mm (L) x 3.94 mm (W) x 4.57 mm (H).
• Weight: Approx. 0.35 grams.
• Mounting Style: Through-hole.
• Thermal Resistance: 150°C/W (junction-to-ambient).

Conclusion

The LM35DZ is a versatile and reliable temperature sensor that offers high accuracy, ease of use, and broad compatibility with various electronic systems. Its linear output, low power consumption, and robust packaging make it an excellent choice for applications ranging from industrial controls to consumer electronics. With no need for external calibration and a straightforward interface, the LM35DZ simplifies temperature measurement in both simple and complex systems.