Nordic introduces first PMIC for tight spaces
Nordic Semiconductor’s first power management device is the nPM1100, a power management integrated circuit (PMIC). It combines a USB compatible Li-ion/Li-Po battery charger and DC/DC buck regulator in a compact WLCSP for space-constrained applications.
The low IQ PMIC for the company’s nRF52/nRF53 series SoCs and other compatible devices. The 400mA battery charger and 150mA DC/DC step down regulator is integrated with a USB-compatible input regulator with overvoltage protection in a WLCSP which measures 2.075 x 2.075mm. The PMIC ensures reliable power supply and stable operation for the nRF52 and nRF53 series multi-protocol SoCs and maximises the application battery life, says Nordic. It can be used as a generic PMIC for any application using rechargeable Lithium Ion or Lithium Polymer batteries. Its form factor makes it suitable for wearables, connected medical devices, and other space-constrained applications.
The nPM1100’s battery charger can bypass the first regulator stage of Bluetooth Low Energy (BLE) applications based on nRF52 and nRF53 SoCs. In this configuration the buck regulator’s high efficiency reduces overall system power consumption while its 150mA current capability increases the current available for other system components from approximately 10 to 100mA.
The nPM1100 features a low quiescent current (IQ) of 700nA (typicall) which can be further reduced to 470nA in “ship mode” (i.e disabling the power output, removing the need for an external power switch), which minimises battery lifetime impact on products in transit. The power management solution takes up as little as 23mm2 of PCB area, including passive components (rising to 27mm2 when optimised for performance).
The nPM1100 input regulator draws its power from either a 4.1 to 6.6V USB input or from a 2.3 to 4.35V connected battery input. It can supply a 3.0 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 over-voltage protection for transient voltage spikes up to 20V.
The battery charger is JEITA-compliant and 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.
The DC/DC buck voltage regulator runs at more than 90 per cent efficiency down to below 100 microA load current. It takes its power from the input system regulator and provides up to 150mA current at a selectable 1.8, 2.0, 2.7 or 3.0V regulated output voltage. The regulator features soft start up and automatic transition between hysteretic and pulse width modulation (PWM) modes. It also supports a forced PWM mode for clean power operation.
No configuration software is required 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 to 85 degrees C.
Nordic also offers the nPM1100 evaluation kit with 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. It can be powered by USB via the on-board 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.