Green initiatives have brought the issue of standby power waste into focus. By reducing the use of standby power, the average American household can save $100 per year*. Additionally, standby power consumption is crucial for the battery life of portable devices, and energy-efficient appliances at home play an important role in reducing environmental waste. This article will explore the issue of standby power in electronic products and discuss ADI's solutions in energy-saving integrated circuits.
Standby power is a key factor in energy waste
I believe most people know the importance of saving energy, but it is often easier said than done, yet extremely important. If energy-saving green thinking is incorporated into the design of electronic products, it can fundamentally address the issue of energy waste. Intelligent circuit designers and many leading companies are meeting consumer expectations in this regard.
To save energy, even the smallest details are crucial. Power efficiency should be measured in microamperes (µAs), which is one-millionth of an ampere. By comparison, a 60W incandescent bulb consumes 0.5A of current, which is 500,000µA. If a 60W bulb runs 24/7, the monthly cost is $14.65. An appliance consuming 1W of standby power costs $0.25 per month without performing any actual work.
Consider the number of appliances in a typical household: TVs, radios, stereos, computers, garage door openers, microwave ovens, washing machines, dryers, forced-air heaters, and lawn sprinklers, plus battery chargers. It’s easy to have 20 devices on standby, and most of them consume more than 1W.
Using low-power components to reduce device power consumption
Why is it necessary to measure standby power so precisely? Because when planning any budget, every cost must be minimized, no matter how small. Clearly, for battery-powered devices, customers are very sensitive to battery life. Less obviously, plug-in appliances also incur costs associated with being plugged into power. When a device is in the "off" state but waiting for a remote command, button, or timer, and displaying a power indicator, it consumes standby power.
Take a cable TV box, for example, which consumes 80W while operating and 79W in standby mode (costing $19.53 and $19.30 respectively). A satellite DVR set-top box consumes 120W whether operating or in standby mode, thus adding approximately $29.30 to your monthly subscription fee.
This is not just about the monthly cost. As global citizens, we must be aware of our environmental impact. As circuit designers, we can make careful choices. Fortunately, low-power components are not necessarily more expensive. In fact, because newer components are manufactured using smaller geometry IC processes, they are often more efficient.
It is estimated that 10% of household electricity consumption is wasted on standby power. The Energy Star® program, initiated by the U.S. Environmental Protection Agency and the U.S. Department of Energy, estimates that 129 million households spend an average of $2,200 annually on electricity. Adding these numbers together, American households spend approximately $28.3 billion annually on standby power. This is a staggering number, and we could save this money simply by turning off the switch.
When we realize that our households can save at least $100 annually, going green suddenly sounds quite appealing. If everyone pays attention to energy efficiency, we can double our environmental efforts. By paying attention to power consumption when selecting components for circuits, although microamperes are a small amount, when multiplied by the large global population, it indeed has an impact.
Green technology enhances energy efficiency of electronic products
Green technology generally refers to technologies that improve the energy efficiency of electronic products. Specific methods include energy efficiency optimization, smart power management, renewable energy utilization, material innovation, recycling and reuse, smart home and IoT technologies.
Energy efficiency optimization improves the energy utilization efficiency of electronic products by enhancing their design and manufacturing processes. Many modern electronic devices use high-efficiency processors, low-power display technologies, and smart power management systems to reduce energy waste. For example, LED display technology is more energy-efficient compared to traditional LCD technology, while the latest ARM architecture processors can significantly reduce power consumption while maintaining performance.
Smart power management systems can automatically adjust power consumption based on the device's usage. For instance, smartphones and laptops enter low-power modes when not in use and turn off unnecessary functions while on standby, reducing power consumption. This technology not only extends the battery life of devices but also reduces overall energy consumption.
The application of renewable energy is also part of green technology, with more and more electronic devices supporting solar charging or using other renewable energy sources. For example, solar panels can provide energy for portable devices, reducing reliance on traditional electricity. Additionally, wind and water energy can provide clean energy for large data centers, reducing carbon emissions.
Innovations in materials science also contribute significantly to energy savings. New materials, such as high-efficiency semiconductors and insulating materials, can substantially reduce energy loss. For instance, components made of new materials like carbon nanotubes and graphene can improve conductivity while reducing resistance, thereby reducing energy loss.
Recycling and reuse are important components of green technology. Effective recycling and reuse can extend the lifecycle of electronic products and reduce resource waste. Many manufacturers now use recyclable materials to make electronic products and consider future recycling and reuse during the product design phase.
On the other hand, smart home and IoT technologies achieve efficient energy use through intelligent control and automation management. For example, smart thermostats can automatically adjust room temperatures based on users' daily routines, smart lighting systems can automatically adjust brightness according to ambient light, and smart plugs can monitor and control the power usage of household appliances, significantly reducing home energy consumption.
ADI's full range of low-power components
To address the issue of standby power consumption, ADI's circuit designers have long considered energy efficiency in their designs. Listed below are several ICs that can be used to reduce the power costs of household appliances, computers, and set-top boxes. Today, designers and consumers have choices, and we can all influence the future of the planet by doing small things every day.
ADI's MAX5052 is a current-mode PWM controller for isolated/non-isolated power supplies, suitable for universal input (rectified 85VAC to 265VAC), with an operating current of 1.4mA and a startup current of 45µA. The MAX669 is a PWM power-supply controller for medium to heavy loads, with Idle Mode™ only emitting pulses as needed under light loads, and a quiescent current of just 220µA.
The DS2786 fuel gauge accurately reports the battery capacity of standard Li+ battery packs, with an operating current of 50µA and a standby sleep current of 1µA. The DS80C320/DS80C323 microcontrollers are compatible with the 80C31, 80C32, and 8051, supporting fast power saving, with 50µA in stop mode with the bandgap on, and 1µA in stop mode with the bandgap off.
The DS80CH11 system energy manager features an 8051-compatible core, supporting key scanning, battery and power management, a 2-wire serial I/O port, 88 parallel pins, 8-channel 10-bit ADC, and 4-channel 8-bit PWM, which can be used to adjust LCD contrast and brightness, with 10mA in idle mode and 1µA in stop mode.
The DS2432 secure EEPROM supports a 64-bit key, SHA-1 engine, and a unique 64-bit laser number identifier, with 500µA during EEPROM write and 5µA in standby. The DS1340 real-time clock and trickle charger, with backup power switching, has an operating current of 800µA.
The MAX894L/MAX895L high-side P-channel MOSFET load isolation power switches have a switches on current of 16µA and a switches off current of 0.1µA. The MAX7306/MAX7307 serial interface peripherals feature 4 I/O ports, supporting simultaneous LED dimming/blinking and key debounce, with a standby current of 0.75µA.
The MAX4789 and MAX4794 switches protect host devices with SDIO memory cards, with an operating current of 80µA and a standby current of 0.01µA. The MAX2830 Wi-Fi® RF transceiver, with PA and diversity Rx/Tx switch, is housed in a 7mm × 7mm package designed for 802.11g/b applications, with a receive current of 65mA, transmit current of 289mA (POUT = 15dBm), and a shutdown current of 10µA.
The MAX9025–MAX9028 comparators, some with a 1.236V ±1% reference, have a current of 1µA with the reference and 0.6µA without it. The MAX8678 WLED charge pump features a 1.1W audio amplifier, no output capacitor, with LED consumption at 140µA and quiescent standby at 0.1µA.
The MAX9723 stereo DirectDrive® headphone amplifier includes BassMax and volume control, with a standby current of 5µA. The MAX9515 video filter amplifier supports autosenses signal and/or output coax load, with a standby current of 5µA.
The MAX9503 video filter amplifier supports DirectDrive to remove output capacitors, with a standby current of 10nA. The DS2714 NiMH battery charger is not for alkaline and lithium cells, consuming 500µA to 750µA.
The MAX6029 is an ultra-low power, high-precision series voltage reference supporting a maximum ultra-low supply current of 5.25µA and a low dropout of 200mV, making it particularly suitable for battery-powered systems.
Conclusion
Through energy efficiency optimization, smart power management, renewable energy utilization, material innovation, recycling and circular economy, and smart home and IoT technologies, green technology demonstrates tremendous potential in conserving energy for electronic products. With continuous technological advancements and widespread application, green technology is set to make significant contributions to energy conservation and environmental protection in electronic products in the future. The series of low-power components introduced by ADI will help electronic products using these components reduce both operating and standby power consumption. Every electronic designer can contribute to energy conservation from the ground up by designing energy-efficient and environmentally friendly electronic products.
(*The residential electricity retail prices mentioned in this article will vary by location and time. These prices apply to residential customers in Northern California at the time this article was published.)