BTN08G SMD NTC Thermistors

Introduction

Bourns’ BTN08G series is a family of surface-mount negative temperature coefficient (NTC) thermistors intended for thermal sensing in compact electronic assemblies. The series combines a 47 kOhm nominal resistance with a 3950 K B25/85 parameter in a standard 0805 footprint, providing a small PCB-mount option for temperature-dependent measurement and control circuits.

What it does

An NTC thermistor exhibits decreasing resistance as its temperature rises. In the BTN08G series, this characteristic can be used by a monitoring or control circuit to infer temperature from a resistance change.

Listed BTN08G devices have a 47 kOhm resistance value and a B25/85 parameter of 3950 K, which describes the resistance-versus-temperature characteristic over the stated reference range. The series is rated for 240 mW and specified for operation from −40 °C to +125 °C.

The available tolerance options are 1% and 3%, allowing designers to select the appropriate resistance accuracy for the requirements of the sensing circuit.

Applications

Potential uses based on the series’ thermal-sensing function include:

• Temperature monitoring in general electronic devices
• Thermal-feedback circuits in power supplies
• Temperature sensing within industrial equipment
• Compact PCB assemblies requiring an 0805 SMD thermistor

Design considerations

The BTN08G uses an 0805 (2012 metric) surface-mount package, measuring 2 mm by 1.25 mm with a 0.85 mm height. This compact format is suitable for dense PCB layouts, but placement should account for the temperature being measured: the thermistor’s reading will reflect its local thermal environment and nearby heat-generating components.

Designers should also account for the device’s 240 mW power rating and select the 1% or 3% resistance tolerance option according to the required measurement accuracy. The stated −40 °C to +125 °C operating range should be considered alongside the expected ambient and board-level temperatures.

Availability and further information

The source/distributor and datasheet links on this page provide further information about the Bourns BTN08G SMD NTC thermistor series.