Week #14: (12/7-11) MOSFETs & H-Bridges, Thyristors & SCRs, Thermal Concepts

[rjagodowski]

Here's a pdf of the answers to the Gain Calculation Assignment posted a few weeks back:

Gain Calculation Problems Solutions v15.1.pdf

(352.86 KiB) Downloaded 36 times

We'll finish up some of the topics on MOSFETs we didn't get to in Week #13.

The MOSFET as a Switch.

MOSFET Switching Tutorial Make special note of the H-Bridge which is commonly used for DC Motor Control.

Here's a YouTube Video on H-Bridge Circuit Construction (8:11)

Here are the key schematics used in the H-Bridge Circuit used in the video above. Note that Darlington Pair (High Beta) Bipolar Junction Transistors are used in this implementation instead of MOSFETs.

H-Bridge Schematic for YouTube Video.png (135.78 KiB) Viewed 1904 times

Current Limit & LED Circuit for YouTube Video.png (65.42 KiB) Viewed 1904 times

Current Limit & LED Circuit for YouTube Video.png (65.42 KiB) Viewed 1904 times

Infineon Power MOSFETs for Automotive Use

Added on 12/14/22:
Here's a modern H-Bridge PWD13F60 with MOSFETs, drivers and control circuit all on a single chip, 13mm x 10mm (roughly 1/2 inch square). Capable of 600V 8A control for various applications with peak 32A capability. It's under $7.00 per unit in quantities greater than 10 from DigiKey per this link: PWD13F60 from DigiKey .


Here's the full data sheet for the PWD13F60.

And here's an Evaluation Board for the PWD13F60 from Newark.com. The PWD13F60 is surface mount so it's difficult to test and use for prototypes. This Evaluation Board makes it easier to integrate it into test and prototype rigs to fully evaluate the capabilities for a specific design application. This is commonly done for many such devices to make it easier for engineers and system designers to work with the new devices.

By the way, on the full data sheet, notice the large solder pads on the bottom of the chip. These serve two purposes. First of all, having a lot of copper soldering surface is necessary for the high currents which might flow and secondly, those large metal pads work as heat sinks for better thermal management of the surface mount IC. Thermal conditions are discussed and presented below.




Here are some tutorial materials we covered BEFORE the SCR Lab:

Shockley Diodes here and Here. The second link shows the two common applications of the Shockley diode as a Relaxation Oscillator and a Trigger Switch.

SCRs: http://www.wisc-online.com/Objects/View ... ID=SSE4803 and http://www.wisc-online.com/Objects/View ... ID=SSE4903, also here: http://www.allaboutcircuits.com/vol_3/chpt_7/5.html

Additional Thyristor Circuits - DIACs and TRIACs.

DIACs: http://www.wisc-online.com/Objects/View ... ID=SSE7706, also here: http://www.allaboutcircuits.com/vol_3/chpt_7/4.html

TRIACs: http://www.wisc-online.com/Objects/View ... ID=SSE7406 and http://www.wisc-online.com/Objects/View ... ID=SSE7506 (special note on slide 6 showing the power controlling waveforms), also here: http://www.allaboutcircuits.com/vol_3/chpt_7/6.html

Here's a YouTube Video on Triac Triggering
(14:48)


Thermal Concepts:

Thermal Resistance Fundamentals

Junction to Case Thermal Resistance

Junction to Ambient Thermal Resistance





Voltage Regulators, DC-to-DC Converters, Linear & Switching Power Supplies

Understanding How Voltage Regulators Work

Here's a link on What is a DC-to-DC Converter?

This is a copy of the pdf the above link provides as a download:

DC to DC Converters_dcdc_seminar_1_e.pdf

(1.71 MiB) Downloaded 33 times

Silicon Carbide (SiC) Semiconductors:

And one last topic for the year. Coverage of Silicon Carbide semiconductors was recommended at our 2023 Advisory Board Meeting on 5/18/23.

Information about SiC Devices & Industries from Microchip.

How SiC MOSFETs are Moade and How They Work Best.