The PMIC combines a USB compatible Li-ion/Li-Po battery charger and highly efficient DC-DC buck regulator in a compact WLCSP package
Nordic Semiconductor has launched its first power management IC (PMIC), the nPM1100, which combines a USB compatible input regulator with overvoltage protection, 400mA battery charger and 150mA DC-DC step-down (“buck”) voltage regulator in a 2.075mm x 2.075mm wafer level chip scale package (WLCSP). The PMIC ensures reliable power supply and stable operation for Nordic’s nRF52 and nRF53 Series multiprotocol Systems-on-Chip (SoCs) and maximises application battery life. The product can also be used as a generic PMIC for any application using rechargeable Lithium Ion or Lithium Polymer batteries. Its extremely compact form factor makes it ideal for advanced wearables, connected medical devices, and other space-constrained applications.
Bluetooth Low Energy (Bluetooth LE) applications based on nRF52 and nRF53 Series SoCs and using rechargeable Li-ion/Li-Po batteries can take advantage of the nPM1100’s battery charger to bypass the first regulator stage of the SoCs. In addition, when used in this configuration the high efficiency of the nPM1100’s buck regulator reduces overall system power consumption while its 150mA current capability increases the current available for other system components from approximately 10mA to 100mA.
Ultra low quiescent current
The nPM1100 features an ultra-low quiescent current (IQ) of 700nA (typ.) which can be further reduced to 470 nA in “ship mode”. Ship mode also disables power output – removing the need for an external power switch and ensuring minimum battery lifetime impact on products in transit. The power management solution takes up as little as 23 mm2 of PCB area, including passive components (rising to 27mm2 when optimized for performance) – much less than comparable competitive products.
The nPM1100 input regulator draws its power from either a 4.1V to 6.6V USB input or from a 2.3V to 4.35V connected battery input; it can supply a 3.0V to 5.5V unregulated voltage to the application at up to 500mA output current. The PMIC supports USB Standard Downstream Port (SDP), Charging Downstream Port (CDP) and Dedicated Charger Port (DCP) detection. The input regulator includes overvoltage protection for transient voltage spikes up to 20V.
The PMIC’s JEITA-compliant battery charger will charge the application’s Li-ion/Li-Po battery with a resistor-selectable charge current from 20 to 400mA and a selectable termination voltage of 4.1 or 4.2V. The charger includes battery thermal protection and automatic selection from three charging modes: Automatic trickle, constant current and constant voltage. The charger also features a discharge current limitation.
High efficiency voltage regulator
The product’s highly efficient DC-DC buck voltage regulator runs at more than 90 per cent efficiency down to below 100µA load current. It takes its power from the input system regulator and provides up to 150mA current at a selectable 1.8V, 2.0V, 2.7V or 3.0V regulated output voltage. The regulator features soft startup and automatic transition between hysteretic and pulse width modulation (PWM) modes. It also supports a forced PWM mode to ensure the cleanest power operation possible.
The nPM1100 requires no configuration software to operate as all settings are pin configurable. The PMIC is compatible with all devices designed to operate within the output voltages and supply currents the chip can deliver. The product’s operating temperature range is -40˚C to 85˚C.
“The nPM1100 marks Nordic’s commitment to establishing a line of PMIC products. Over the past decade, we have made it easy for the world to connect things to the Internet and it makes a lot of sense that we also help the same customers charge the batteries in the same things and further extend battery life,” says Geir Kjosavik, Product Manager for Nordic’s PMIC range. “The resulting platform leverages Nordic’s low power expertise by combining proven technology blocks to offer even more ways to conserve energy. We are kicking this off with a device that targets the smaller applications by enabling charging of small batteries while providing efficient power management where physical space is at a real premium.”
Evaluation kit
The new PMIC is accompanied by the ‘nPM1100 Evaluation Kit’. The Evaluation Kit (EK) features switches for all selectable settings, buttons to enter and exit ship mode and connectors for batteries, USB and headers for all pins on the PMIC. The headers allow for overriding switches if SW control of configuration is required. The EK allows for testing of the nPM1100 PMIC’s capabilities with existing applications without the need for creating custom hardware. The EK can be powered by USB via the onboard micro-USB port, from an external DC power supply through header pins or from battery power via the battery connectors on one of the headers. The EK is designed for use with other Nordic Development Kits (DKs) or to test out the PMIC’s functionality with non-Nordic products.
The nPM1100 is in volume production and samples are available now. Nordic is presenting a webinar on June 9, 2021, intending to familiarise engineers and others with the nPM1100.
