EYE ON NPI - Nordic Semiconductor nPM1100 Power Management IC

Adafruit Industries

It's getting hot here in New York City, we could use a little help cooling off, and this week's EYE ON NPI an ultra-cool blast of Nordic engineering - the nPM1100! It's the first power management IC from our favorite low-power-wireless company, Nordic Semiconductor. We've featured them on EYE ON NPI before - the Nordic Power Profiler Kit II (https://blog.adafruit.com/2020/12/03/eye-on-npi-nordic-power-profiler-kit-ii-eyeonnpi-digikey-nordictweets-digikey-adafruit/) and the nRF53840 microcontroller (https://blog.adafruit.com/2020/03/20/eye-on-npi-nordic-semiconductors-nrf5340-bluetooth-eyeonnpi-maximintegrated-digikey/) - and we've been using Nordic BLE chips for quite a while in our Bluefruit line of boards (https://www.digikey.com/en/products/filter/rf-evaluation-and-development-kits-boards/859?s=N4IgTCBcDaIEYBsCuBTAZgJyQSwC4gF0BfIA) For us Nordic is synonymous with Wireless and Low Power. That's their bag, and if you need something that's BLE and runs on a small battery for a long time, it's probably the product like you're going to use. Even Apple, who have gotten serious into designing their own silicon used the Nordic nRF52 series for the AirTag (https://www.ifixit.com/News/50145/airtag-teardown-part-one-yeah-this-tracks) When you make products that are designed and marketed to be used for low power wireless - like motion trackers, beacons/tags, fitness watches/bracelets, environmental monitor, etc. the power management system becomes less of a independently-run subsection of the electronics design. As we've seen in other EYE ON NPI's, there may be times when you drop the voltage down or raise it up to change quiescent current and RF transmission. A lot of Cortex chips we've seen lately have integrated buck converters that can be enabled/disabled on demand - they have higher quiescent current than LDOs, but may have lower overall run current during high draw. Buck converters also require an inductor, of course, and will have higher noise. Getting long life from battery is very hard, much harder than people think, and requires good firmware, hardware and integration design. Given the creating of the PPK2, it seems obvious to us that a lot of Nordic's time has been spent trying to get their their customers going with the battery performance they need without doing their design for them. A lot of time folks don't understand the way quiescent currents add up to drain batteries. To solve this for Nordic's customers, they've pulled the PMIC's that were historically integrated into the nRF52840 (https://www.digikey.com/en/products/detail/nordic-semiconductor-asa/NRF52840-QIAA-R7/11200025), nRF5340 (https://www.digikey.com/en/products/detail/nordic-semiconductor-asa/NRF5340-QKAA-R/13559661) and nRF9160 (https://www.digikey.com/en/products/detail/nordic-semiconductor-asa/NRF9160-SICA-R/12339212) and super-powered it into the nPM1100 (https://www.digikey.com/short/38n9f9dv) - an all-in-one battery charger, regulator and buck converter. Ultra-small form factor PMIC 2.075 x 2.075 mm WLCSP package 400 mA battery charger Termination voltage: JEITA compliant 4.1 V or 4.2 V selectable Charge current: 20 mA to 400 mA Highly efficient Buck regulator Output voltage: 1.8, 2.1, 2.7 or 3.0 V Current limit: 150 mA output USB compatible input regulator Overvoltage protection Ship mode disables power output Quiescent currents: 800 nA typical, 460 nA in ship mode Drivers for charge and error LEDs -40°C to 85°C operating temperature Things we like - this chip is fully standalone and strapped with resistors or pins so you don't have to configure it over I2C or 1-Wire or anything and two direct LED outputs for instant visible feedback with a bi-color LED. Works with USB but has input protection for higher voltages in case something gets mis-plugged. Three-in-one integration design means you can pick and choose the pieces you want. It's clearly designed for boards that use sporadic power, and has a 'ship mode' to reduce power draw while its in storage/shipment to the customer - many of these devices don't have a true Off button/switch, so before the first use they'll want to be disabled/enabled with soft-switch buttons to wake up. In Nordic's case studies, they were able to up the run time of a wearable health-monitor bracelet by taking advantage of the buck converter to reduce run-time quiescent current. While designed for Nordic wireless chipsets, this PMIC would be well suited to wearable/low-power designs and you know that Nordic takes low power very seriously so this chip will hit the ground running with a tiny chip that does it all. Bare nPM1100 chips (https://www.digikey.com/short/5dwz72j7), as well as the eval boards (https://www.digikey.com/en/products/detail/nordic-semiconductor-asa/NPM1100-EK/14310011?s=N4IgTCBcDaIHYAcC2BGFAGdIC6BfIA) are in stock right now for immediate shipment! Order today and you can integrate into your low-power design to reduce space and increase battery life all at the same time.