Hendon Semiconductors – Microelectronics Design

Products include integrated circuits (silicon chips) in Bipolar, Bi-CMOS and CMOS technologies, thick film hybrids (ceramic substrate) and surface mounted printed circuit board assemblies and modules.

Hendon Semiconductors – Microelectronics Design

History -“The Hendon business site in Adelaide, South Australia has been a long established integrated circuit design and wafer fabrication facility in Australia, from its Philips semiconductor background up to 1997…”

Hendon Semiconductors

Thick Film Hybrid Technology

The advantage of ceramic hybrids over fiberglass printed circuit is their high reliability due to their inherent rugged construction with the following advantages:

Hendon Semiconductors Pty. Ltd
ABN: 17 080 879 616, 1 Butler Drive, Hendon, South Australia 5014, Australia.

3-1/2 Digit ICL7107 DPM Digital Panel Meter

This is a Digital Panel Meter based on ICL7107. This was the workhorse Digital Readout chip before Low power uC designs were developed. Even now it is the easiest way an analog parameter can be displayed in an instrument.

Instrumentation and Measurement Circuits

3-1/2 Display is just enough resolution for recording process data or troubleshooting equipment. With 4-1/2 you notice the problems of thermoelectric EMF of probes and connectors. That is one reason gold plating is used another being low contact resistance. In 4 1/2 the reading can change due to contact resistance too, if the input impedance of the analog signal conditioning is low or the protection diodes, RC filter caps are leaky.

ICL7107 DPM Digital Panel Meter

When you measure an analog parameter from a sensor; you attenuate or amplify it, to scale to the A/D converter range. You also need to protect or isolate the analog front end from high energy mis-connections, which will happen during field use. The operator should not get injured from any high energy leakage while measuring.

Resolution is the finest detail you can enumerate in a parameter or object. You can say the crowd was 3000 or 4000 people. Here 1000 is the resolution, finer data does not matter here. You would also hear things like, there were 80 to 90 boys in that classroom. 10 is the resolution there.

Accuracy is how precise a statement or number is. If there was 85 boys in that class, the above statement is accurate. If there was 65 boys, the measuring method or process needs calibration or examination.

In this circuit, the plastic caps should be of very low leakage. Multilayer plastic caps are good for instrumentation.

The MOSFET in Power Electronics

delabs Notes – In a Circuit Module, if all Power and Signal Polarities are reversed. All NPN to PNP, All N-Channel to P-Channel and Vice Versa. All Diodes and Caps too turned around. This Topsy Turvy or Mirror Design ought to work in Theory. It has worked for some circuits in practice too in my experience. ?

Some believe that N-Channel is more Robust than the P Type. In Bipolar Transistor NPN is more trusted for the final output stages. The NPN Transistor and N-Channel turn-on by a Positive control bias. It may be inappropriate to say this mosfet is NPN or PNP.

The MOSFET in Power Electronics

The traditional metal–oxide–semiconductor (MOS) structure is obtained by growing a layer of silicon dioxide (SiO2) on top of a silicon substrate and depositing a layer of metal or polycrystalline silicon (the latter is commonly used). As the silicon dioxide is a dielectric material, its structure is equivalent to a planar capacitor, with one of the electrodes replaced by a semiconductor.

If the MOSFET is an n-channel or nMOS FET, then the source and drain are “n+” regions and the body is a “p” region. If the MOSFET is a p-channel or pMOS FET, then the source and drain are “p+” regions and the body is a “n” region. The source is so named because it is the source of the charge carriers (electrons for n-channel, holes for p-channel) that flow through the channel; similarly, the drain is where the charge carriers leave the channel. MOSFET – Wikipedia

This application note discusses the breakdown voltage, on-resistance, transconductance, threshold voltage, diode forward voltage, power dissipation, dynamic characteristics, gate charge and dV/dt capability of the power MOSFET.
Application Note AN-1084 Power MOSFET Basics – IRF

A MOSFET is a transistor. It is a Metal Oxide Field Effect Transistor. Here are the symbols for FETs and MOSFETs: The MOSFET How the MOSFET works

The conductivity of the path from Source to drain is controlled by applying a voltage between the gate and the body of the semiconductor. N-channel enhancement MOSFET

See this simple circuit that explains everything
n-channel MOSFET switch – George Watson, Univ. of Delaware, 1996.