Kaitlyn Wigan Horne, an Applications Engineer from Texas Instruments will discuss the key specifications of wide input DC DC converters that service field transmitters and process sensors.
In this video, you will be looking at an example block diagram for a field transmitter specifically. This is an example of a temperature transmitter, these sensors are used to measure process conditions such as temperature pressure or position. You can see highlighted in red, the non isolated power supply subsystem.
This presentation will focus on the key specifications of this subsystem, first you can see that this subsystem is powered from a 24V DC rail nominal voltage. In addition, it is required to be able to withstand a wide input voltage range in order to handle the associated voltage transients. Secondly due to the small form factor of these sensors it is key that the front end supply has minimal component count in an optimised total solution size.
Many of these sensors utilise a 4-20mA loop sensing methodology. Consequently, the power subsystem must operature with high efficiency at ultra light loads.
And lastly, the sensors require a low noise power supply in order to enable a low output ripple.
In the video, you will be looking at a block diagram for the 4-20mA loop sensor applications, the designs focus on the signal processing portion of the sensor applications. In red you will see the pre regulator is highlighted, there will be a requirement for a DC DC converter to convert the nominal 24V rails.
In addition, these two reference designs are designed for the 4-20mA loop sensing methodology so that means that our wide input DC/DC converter is going to need to operate at a load of a few mA and still be able to maintain a high efficiency again.
For more information, watch the video below.