With the surge in battery-powered applications, demand for high-quality, affordable batteries and battery packs continues to soar. Battery manufacturers are constantly adopting new chemistry and introducing smaller sizes, which brings new and complex limitations and requirements. However, the fundamental requirement for battery functionality remains unchanged: to extend runtime and shelf life without compromising system performance.
Minimizing quiescent current (IQ) is a priority for reducing power consumption and extending battery life. A device's IQ is the current flowing out or the amount of electricity consumed when the battery is in standby mode or under light load. IQ significantly impacts a device's energy efficiency. In battery-powered applications, achieving high energy efficiency under no-load or light-load conditions requires implementing power management solutions that strictly control output while maintaining ultra-low supply current.
Many modern designs require only a few nanoamps of IQ, a capability that benefits numerous applications requiring extended standby time, from electric vehicles (EVs) to power tools and various headphones. Since these systems spend over 99% of their time in standby or sleep mode, IQ in standby or sleep mode is a limiting factor for battery life. Optimizing power management components and devices, such as DC/DC converters, low-dropout regulators (LDOs), power switches, voltage references, and monitors, helps reduce energy consumption and extend battery life.
Below are our three low IQ technologies that can extend battery life and shelf life without affecting system performance.
Supports the design of low-power, normally-on power supplies.
Ultra-low leakage current technology and a novel control topology extend battery runtime. Achieving ultra-low IQ when the system enters standby mode further extends battery runtime. The TPS37-Q1 monitor exhibits a typical IQ of 1µA when performing EV battery monitoring, while supporting supply voltages up to 65V without compromising power margin or response time.
Battery charger integrated circuits (ICs), such as the BQ25155 with an IQ of 10nA in chip mode, help ensure that batteries can remain charged for months or even years on the shelf. Low-power regulators, such as the TPS7A02 with an ultra-low IQ (25nA) and an IQ of only 3nA in shipping mode, help significantly extend battery life in normal and low-dropout operating modes.
Achieve rapid response
Fast wake-up comparators and zero-IQ feedback control enable rapid dynamic response without compromising low-power performance. Intelligent biasing instantly boosts the comparator voltage upon error detection, improving response speed without consuming more IQ. For example, the TPS62843 buck switching regulator, with a typical IQ of 275nA, offers a response time × IQ/ILOAD value more than three times faster than previous generations. Furthermore, the TPS37-Q1 boasts industry-leading response and detection times (typically 8µs), two to ten times faster than competitors.
Reduced external dimensions
Area reduction techniques for resistors and capacitors facilitate integration into space-constrained applications without compromising quiescent power. In next-generation nanowatt-scale devices, most external pull-up or pull-down resistors and external resistor divider networks are no longer needed, and the form factor is significantly smaller; for example, the TPS7A02 uses a 640µm x 64µm chip-scale package.
Another way to save board space is to integrate more functionality onto a single die. This integration allows modules such as monitors, reference systems, low-dropout regulators, battery chargers, and DC/DC converters to share common building blocks, while reducing the overall IQ size. The BQ25125 is a battery charger management IC in a 2.5mm x 2.5mm wafer chip-scale package that integrates via I2C and provides flexible control over multiple low-IQ functions. Designers can therefore power multiple low-power applications with the entire power management system.
Conclusion
Battery-powered applications are now ubiquitous, and there's a growing demand for lower IQ without compromising system performance—a challenging task. But don't despair. Texas Instruments' portfolio of products built on ultra-low IQ technologies allows for ultra-low power consumption in next-generation battery-powered designs, maximizing battery life and shelf-life without the hassle of balancing performance and cost.
