Performance Upgrade - Demke DC-Transformer 145E Serie
Demke DC/DC buck converter with wide range input from 16...100VDC, output voltages from 13.8V to 29V and 240W
No other Demke DC-Transformer (non-isolated step-down DC/DC Converter) as the 145-serie is:
- built in several variants
- has a higher power density
- is faster in compensating load steps
- has higher quality components
- is more climate-proof
As a part of our ongoing product and component care management, we have got even more performance from the 52x77x19 mm DC/DC converter. The total weight of a 145 DC/DC converter is typically 166g. We first describe the impressive performance of the 145E-13.8-SD, as it has the highest output current of 12A and the lowest output voltage of 13.8V and therefore has the lowest efficiency of the 145E series. Nevertheless, we achieve the specific power of 1W/g! With internal input and output filters!
In comparison to this version, the DC/DC buck converter without galvanic isolation, the 145E1-27.5-SD with 27.5V output voltage at an output current of 8A, with 220W power or 1.32W/g specific power is described. Due to the high ampacity and high saturation currents of the filter elements used, we further reduce drastically the noise of these DC/DC converter series. State of the art Mosfet driving and Mosfets itself increase the efficiency by more than 1% throughout the entire working range of the 13.8V version.
The internal reverse polarity protection diode located on the output-side in the so-called E-version provides the necessary decoupling of a battery connected directly to the DC output. At the same time, this reverse polarity protection diode that prevents the reverse discharge current from the connected battery, is the component with the most internal losses, which are only caused by Vf*If.
Figure 1: Efficiency vs. output current (CV-mode) of the galvanically non-isolated DC/DC buck converter Demke 145E-13.8-SD at different input voltages.
Figure 2: Efficiency vs. output voltage (CC-mode) of the galvanically non-isolated DC/DC buck converter Demke 145E-13.8-SD at different input voltages.
Figure 3: Efficiency vs. output current (CV-mode) of the galvanically non-isolated DC/DC buck converter Demke 145E1-27.5-SD at different input voltages.
Figure 4: Efficiency vs. output voltage (CC-mode) of the galvanically non-isolated DC/DC buck converter Demke 145E1-27.5-SD at different input voltages.
We have attached great importance to the refinement of the complete control theory in all operating conditions. Load jumps in constant voltage mode (CV) as well as in constant current mode (CC) are now controlled in full perfection.
With the aid of the latest technology and measuring techniques, we achieve even faster settling times of load jumps, with lower deviation from the output voltage setpoint. All detailed information can be found in the technical data sheet of the DC/DC converter 145E-13.8-SD and in the technical data sheet of the DC/DC converter 145E1-27.5-SD.
At this point, we would like to explicitly point out that customer-specific modifications are quite "easy" to make. Take a closer look at the DC-Transformer Master 14XE. If you have any questions, please call us or use the chat function on dc-transformer.ch In principle, everything is possible, on the input side with Vin = 8V...220VDC, on the output side with Vout from approximately 4V...80V at power ratings up to 250W. We will provide a look on the 144-24-SD very soon, this Demke DC/DC converter with an extended input voltage range of 22...160VDC is very interesting for AGV`s (automated guided vehicles) and shuttle applications.
Our little high performance baby has always been good - now, about eight years after the first delivery, we ask ourselves the question if this converter can be built even better - but probably in 10 years we will see things different again.