Dialog Semiconductor’s new PMIC addresses the design issue …

Dialog Semiconductor’s new PMIC (Power Management IC) aims to help solve the problem of battery life for wearables and other small and portable applications, a challenge now familiar to many IoT device designers.

Last week Dialog Semiconductor released its latest PMIC designed to manage the power of IoT devices that need to extend battery life (probably most of them).

For more information, AAC spoke with Faisal Ahmad, Director of Marketing for Dialog Semiconductor, for his power management and audio products within the mobile systems business unit.

Here’s a look at the most important features of this IC, the importance of fuel gauges in wearables, and where the wearables market is heading.

Power management for small IoT applications

The DA9070 is a nano-powered PMIC designed to power IoT equipment. One of the main focuses of this product is wearable devices like fitness trackers, but IoT here could also mean smart home or building automation applications, or even key fobs.

The goal is to extend the life of small batteries, especially in those applications where there is some kind of always-on functionality (for example, a sensor for home automation or a clock for a wearable device).

This chip draws a very low quiescent current while maintaining the voltage regulation required by system components.

To achieve this, the DA9070 features the following components:

  • Battery charger for rechargeable battery.
  • Regulator buck to power system MCU
  • Push the regulator to turn on the display or high voltage sensor
  • Three linear regulators to power other I / Os or sensors
  • Analog battery monitor to create a fuel gauge for the device
Block diagram for the DA9070. Click to enlarge

A fuel efficient gauge

This last feature, the fuel gauge, is important. Small IoT devices often have a bar indicator to measure how much battery is left (for example, three bars indicate ~ 75% remaining battery life where two bars indicate ~ 50%). Ahmad says this is because fuel gauges generally draw a lot of current, draining the battery they are measuring.

“Our fuel gauge only consumes 4 μA and it actually works on the system’s MCU, so it’s very economical,” he says. “It takes the voltage and current information from our PMIC and creates the fuel gauge.”

The fuel gauge interface

The software available on the Dialog website makes this meter easy to use, including “a complete set of software that guides you through the process of creating a fuel meter.”

DA9070 development board

The DA9070 has a development board that designers can work with. The board comes with an 80mA per hour battery, a common size for, say, a fitness tracker. In addition to the PMIC, a typical MCU (an ARM Cortex m4 core) is also included, loaded with Dialog Semiconductor firmware to measure voltage and current and to run the algorithm to create a fuel gauge.

DA9070 development board

An integrated solution with some flexibility

Small design problems often require solutions with small footprints. As Ahmad puts it, “We are solving the problem with a highly integrated solution because many of these systems are very small.”

While this level of integration is important for this particular PMIC, according to Ahmad, it is also “flexible enough that multiple regulators can be used for different circuits” depending on what is happening in the system.

“This part is perfect for someone who has the challenge of trying to fit their circuit into a small space and make their battery last as long as possible,” he says. “All the components of the device are really optimized to optimize battery life. Everything can also be controlled digitally via an I2C interface is like this: if you are a systems designer who has more experience in embedded design, when writing code in an MCU, it makes it really easy to control the device with the controller we provide and control everything digitally. ”

Dialog Semiconductor and the future of IoT

Ahmad believes that the market for wearables is still relatively new. It’s only been a few years, he notes, that we have been able to purchase fitness trackers at major stores. In the next few years, think that wrist wearables can take hold. “But,” he says, “we are still seeing a lot of innovation and new ideas just for wearables other than [those that are worn on the] doll. “In fact, the wearable umbrella is widening, including jewelry such as rings and pendants, shoes and even textiles directly on clothing.

One of the reasons the wearables market is likely to continue to grow, says Ahmad, is that “overall, one of the main driving forces behind having wearables is improving your health. It’s a huge market. It should be a priority. for most people. If you’re helping do that, there will always be an opportunity there. “

For Dialog Semiconductor, this is good news. “We see [the IoT space] growing. In general, for our power management, we all care about efficiency and battery life, “says Ahmad.” And this is a market where that is the big problem, so it is an excellent option for us from a technological perspective. “

What challenges have you encountered when trying to power small IoT devices? What methods have you used to try to solve them? Let us know in the comments below.

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