Such an increase is duo to resistive ballast used and can be understood in terms of a negative temperature coefficient
of the LEDs forward voltage, which has typical values of about -2 mV/[degrees]C.
Most thermistors have a negative temperature coefficient
, where resistance decreases as temperature rises.
It is designed with a built-in LED driver and has a negative temperature coefficient
to protect LEDs from thermal runaway at extreme voltages and currents.
The cubic [SrTiO.sub.3] phase has a high dielectric constant but a negative temperature coefficient
. This is a potentially useful microwave ceramic that requires second-phase compensation.
The first is a power-sensing termination, which is based on a linear negative temperature coefficient
(NTC) thick-film thermistor used in combination with a linear positive temperature coefficient (FTC) material to convert RF power to DC voltage.
The objective of this paper is to show that conductive polymer composites produced by hot compaction of a mixture of carbon black and ultra-high molecular weight polyethylene powder exhibit a large positive temperature coefficient (PTC) and no negative temperature coefficient
(NTC) effects even at temperatures significantly above the melting point of the polymer.
The surface mount Series 2322 615 3x (0603 package) and 2322 615 5x (0805 package) negative temperature coefficient
(NTC) chip thermistors are suitable for temperature compensation, sensing and protection circuits in applications such as battery chargers, switch mode power supplies and automotive systems.
Materials with a negative temperature coefficient
of dielectric constant are used for compensation of oscillators and VCOs exhibiting a negative frequency and temperature coefficient.
These high-performance negative temperature coefficient
thermistors feature an operating temperature range of-50[degrees]C to + 110[degrees]C and are available in all resistance-temperature (R/T) curve materials.