An embedded system's low power consumption is crucial for building a battery-powered product. There isn't a single guideline that can be applied to every situation. System design, electric circuit design, and firmware design are all definitely involved. So, what approach should a design engineer take?
Making concessions is typically a necessary part of the design process for new electronic devices and circuits. Costs and performance frequently conflict. The most crucial choice that influences performance may be selecting the appropriate microcontroller or microprocessor for the embedded system in cost-sensitive industries that are focused on consumer goods. The performance of the embedded system may be impacted by a number of conflicting aspects. Let's look at the following elements in this article:
Battery Life
Thermal Performance
Responsiveness
Wireless Signal Range and Speed
Functionality Supplied by External Peripheral Components
When it comes to battery-powered gadgets or electronic devices and circuits that rely on energy-harvesting technology, designing for low-power is crucial.
The following list of 10 suggestions for creating low-power embedded systems:
The circuitry's operating voltage:
As power usage is directly linked to operational voltage, keep the board's overall operating voltage low. Use the smallest voltage you can. For instance, if all the chips can operate at a voltage of 2.7, we can set that voltage for the entire board while maintaining a tiny margin. It makes logical to have two sets of power rails on the integrated board if doing so would result in significant power savings, even though doing so will require an additional DC-DC converter and certain digital-level translation chips.
Operating voltage of power-hungry devices:
Lower voltage operation of power-hungry electronic devices and circuits will minimize power consumption; however, additional dc-dc converters or LDOs may be required to interface with other circuits (operating at different voltage level). Before making a decision, take into account the wake-up time, power savings, additional work, and additional expenses.
Making the right choice:
Choosing the appropriate ICs (ADC, DAC, Relays, etc.) is crucial when taking into account the entire power budget. Choose ICs with low operational voltage ratings and low power (active/idle) consumption.
Additional Interface Modules:
You could be required to select pre-made modules. When making a choice, take into account the power requirements of communication interfaces (RS232/RS485), IoT modules (WiFi, Bluetooth, Sub GHz RF, etc.), cameras, sensors, etc. Comparing their power-up times, active power usage, and idle power consumption parameters is ideal. Making the appropriate technological choice is also crucial. Consider which technology—WiFi, ISM RF, BLE, Zigbee, etc.—will be more appropriate from the standpoints of both user experience and power consumption, for instance, if you need to use RF to transfer data. Choosing the incorrect technology will frequently make it challenging to later optimize power consumption.
Power gating the peripherals (ON/OFF control):
A electronic devices and circuits can be designed with a power control mechanism that turns it OFF when it's not in use. Keeping communication modems ON all the time, for instance, may be costly in terms of power consumption; therefore, if a power ON/OFF control is provided, the device may be powered down when not in use. turning off the printer or LCD while not in use, or even turning off minor components like the ADC, sensors, etc. Please take into account the power required during the power-up (devices cannot be used during this time) and the time needed to complete the power-up. Due to these conditions, it might not be possible to turn off the device in some situations.
Power Supply
It's crucial to choose the proper input voltage for the integrated board. Regardless of whether it is a DC input from a power supply adaptor or a battery input. It is preferable to use a 6V power input rather than a 12/24V DC input or battery input if all of the electronics on the board is supplied by 5V or 3.3V. Voltage differential will affect power loss in a direct proportion.
If it is not limiting the performance of the circuit, utilise a switching DC-DC converter for onboard voltage conversion rather than an LDO or linear regulator. When converting power, linear regulators are incredibly inefficient; they operate in a mode called dissipation, where the power equal to the voltage difference times the current is lost as heat.
LED:
If there are onboard LEDs, which can easily consume 1 to 5 milliamperes (mA), you can do the following:
If feasible, take off the LEDs
less LEDs should be used
Instead of turning the blink LED on all the time, use one with a greater series resistance value to lower the brightness. With 10%-time LED ON, you can signal that the LED should be off and only turn on when necessary or when the user interacts with the electronic devices and circuits.
Display
An engineer has a variety of display alternatives, including the 7-segment display, paper display, OLED, character LCD, monographic LCD, glass LCD, and TFT, among other components of electric circuit. Typically, the display can account for between 50 and 60 percent of the overall energy used. When choosing a display for a design, it's crucial to take power consumption into account. Other methods, such as power gating backlight, full display, and the appropriate colour scheme (dark, the grayscale mode), can considerably minimize the power consumption if the high power-consuming display is required. Power consumption will also be impacted by the display's size.
Pull-ups:
When performed at their best, pull-ups can lower power usage. The main applications for pull-ups are I2C, keys, etc. A few milliamps can be saved with each pull-up. For instance, instead of 4.7K or 1K pull-ups, think about using 22k/10K pullups (if performance is not affected). The pull-up will drain 3.3mA at 3.3V while the pin is at zero and 330uA at 10K, respectively.
The following are further advantages of low power design embedded system:
Better for the environment is less heat. One KWH (1 unit of electricity) is equal to one watt of power saved for every 1000 devices.
Increases dependability. Since fewer components are left on for extended periods of time and less power is wasted, the embedded system's operating life is improved.
In some circumstances, it may lower the production costs since the chosen component is affordable or the low wattage power supply design is easier and less expensive, etc.
There are many strategies to save energy, but not all of them may be appropriate for all use cases. Before making a decision, take into account a number of factors like user experience, reaction speed, design complexity, size, cost, etc.
Conclusion-
All these factors should be considered when building low power design embedded systems, but you should also measure real power consumption using a circuit or piece of measuring equipment. You will be able to decide what steps to take to further control it once you are aware of the exact power consumption. Power can be measured in a variety of ways. Using a multimeter manually, you can measure voltage and current and then calculate power. On the integrated board, set a condition and use meters to manually measure it. Although it is not the ideal method, this one might be effective in certain circumstances.
Any embedded product must be tested in a real environment or under simulated stress conditions in order to function properly in the field. When evaluating your low-power embedded system, make sure to simulate these scenarios. Visit Campus Component to find the right components of electric circuit for all your designing building process at the most reasonable prices and guaranteed quality.
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