Contents
What is avalanche ruggedness?
Avalanche ruggedness is the energy allowable in a single pulse. The channel temperature is the maximum channel temperature Tch(max) on the condition that the rated avalanche current IAS will not be exceeded when single-shot avalanche energy is applied under the prescribed conditions.
What is avalanche rated MOSFET?
So Avalanche Energy is defined as the amount of energy the MOSFET can withstand when it is set into avalanche mode or its breakdown voltage is exceeded. And that value is determined by the Avalanche Current, which is done during an Unclamped Inductive Switching test.
What is unclamped inductive switching?
What is Unclamped Inductive Switching? Whenever current through an inductance is quickly turned off, the magnetic field induces a counter electromagnetic force (EMF) that can build up surprisingly high potentials across the switch.
What is the main cause of Zener breakdown?
The main cause of zener breakdown is high doping concentrations. For heavily doped junctions, when reverse voltage is increased, the electric field at junction increases (as more carriers are present now to create such a pull) which causes covalent bonds to break.
What is UIS testing?
The avalanche ruggedness of a device can be measured using a test circuit that performs an Unclamped Inductive Switching (UIS) function like the one shown in Figure 2. This type of circuit mimics the actual application where unclamped inductive loads are present.
Why do MOSFETs need to be rugged against Avalanche?
MOSFETs to avoid having to move to a higher voltage class. As a result of the high number of ‘special cases’ within the multitude of applications where MOSFETs are used, ruggedness against avalanche is a key requirement for users that MOSFET manufacturers cannot afford to ignore during any new technology development.
When did power FETs start to be called Avalanche rugged?
Power FET manufacturers began advertising their transistors as “avalanche rugged” in the mid-80s. While there was – and still is – some confusion as to what this means, many modern power FETs have a degree of robustness in the face of avalanche conditions.
What do you need to know about avalanche?
2.1.1 Brief reminder about avalanche The avalanche mechanism has already been comprehensively explained in other publications, such as [1]. It originates from an operation above the VBR(DSS)of the FET, which then induces electric fields in excess of the critical electric field (EC).
Which is avalanche safe under its own application conditions?
MOSFET is avalanche safe under their own application conditions. Finally, a formula supplied in section 3.3 assists with rapid computation of avalanche energy when the circuit presents a different loop inductance. Some key facts about avalanche 1 Introduction Application Note 3 Version 1.0 2017-01-9 2 Single pulse avalanche