It can be a quite a challenge for engineers responsible for various aspects of a complex power board to choose a regulator that’s optimum for that specific point of load. While many suppliers offer good solutions, that doesn’t assure you the right regulator for a specific application. For instance, a power IC that designed for automotive applications might not be the right choice for consumer products and vice-versa.
Portable power systems such as the ones used in military applications present a very unique set of challenges. This is because there is a rise in the processing power, with a decrease in battery runtime. Equipment that has low-noise analogue front-ends and sensitive RF circuitry poses an even bigger challenge when switching regulators are used.
In higher current applications and outdoor settings, efficiency is the most important requirement. The engineers need to decide which power features are vital to the application and then choose a regulator that best suits those requirements. Let’s understand how to choose a regulator for your portable military power system below.
The details matter
When choosing a regulator for any portable applications, the load usage and duty cycle and are crucial details. The latter refers to how loads behave. Under standard operation, are these loads constant or do they vary very frequently between the minimum currents to the maximum full-scale currents? Duty-cycle operation is essentially the ratio of the duration for which the equipment is active to the overall time that it spends in a low-current or idle state.
So exactly what is the relevance of all of this? Load usage is vital because it helps determine the IQ (quiescent current). For instance, if the regulator spends most of its time in a fully-loaded condition, then you may not have to focus entirely on choosing a system that has an ultra-low IQ. This is especially the case if the average load current is significantly higher than the system’s rated IQ.
In this situation, if the operation duty cycle is very low, & if the regulator system’s output isn’t a keep-alive voltage (can be shut-down during sleep and idle modes), then it may be more important to opt for a regulator that has a lower shutdown system. If the existing duty cycle is very low and you need to keep the regulator switched on, then it becomes more important to choose a regulator with a lower IQ.
In addition, if the regulator system, during normal operation spends the same amount of time servicing the light loads as it does with the full loads, then it becomes vital to have an ultra-low operating current, to optimise battery runtime and efficiency.
The right control scheme
The regulator control schemes play a vital role in this decision. The different schemes to choose from include:
- PFM or hysteretic schemes – These are generally used where the efficiency has to be optimized at lighter loads.
- PWM or Pulse-width modulation schemes – These are required when lower output noise is needed; these converters operate at certain frequencies making them easier to filter.
Some regulators also have a dual-mode operation, and can switch between the PWM & skip operation modes. In the skip mode, the overall power efficiency improves at lighter loads compared to using the PWM mode. Switching regulators are a good choice for portable military power systems.
If you want to know more about our power products and services, don’t hesitate to contact us at KaRaTec Power Supply Pty. You can give us a call at 612 9808 1127. You can also fill in this contact us form.
Thanks for reading,
Karatec Power Supply Pty
612 9808 1127