Nordic Semiconductor Launches a Tiny USB-Compatible Power Management IC

The nPM1100 includes a USB driven system regulator, a 400mA battery charger and a 150mA buck regulator, all contained within a 2.075 x 2.075 mm wafer level chip scale package (WLCSP) 

Block diagram of the nPM1100. Image courtesy of Nordic Semiconductor

As illustrated above, the nPM1100 draws its power from a 2.3 to 4.35-volt battery pack or from USB (4.1 to 6.6 volts). The system regulator can supply the application to be powered with unregulated voltage ranging from 3.0 to 5.5 volts at up to a half an amp, while the buck regulator provides either 1.8, 2.1, 2.7 or 3.0 volts at 150 mA. The unit can also exploit the USB’s power to charge the application’s battery

 

Low Quiescent Current

The nPM1100 features a typical quiescent current (IQ) of 700nA (typical), and in ship mode, the nPM1100’s quiescent current reduces to only 470 nA.

Ship mode, as the name implies, is the state into which the PMIC is placed while the device is being shipped, or is otherwise not being employed in its designated purpose. In ship mode, the device's output is turned off, saving the power stored in the battery for when it is needed.

 

Charging the Battery

The PMIC’s battery charger is compliant with JEITA and will serve to charge an application’s lithium ion or lithium polymer battery. Charge current ranging from 20 to 400 mA is selectable via external resistor. Termination voltages are 4.1 or 4.2V. 

The unit features automatic selection from either automatic trickle charging, constant current charging or constant voltage charging.

The charger offers battery thermal protection and discharge current limitation.  

 

USB Standards

The PMIC supports: 

• USB Standard Downstream Port (SDP)
• Charging Downstream Port (CDP) 
• Dedicated Charger Port (DCP) detection

The input regulator, which is fed by the USB input, features overvoltage protection for transient voltage spikes of up to 20V.

 

Nordic’s Commitment

“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.”  

 

Applications

The PMIC was designed with Nordic’s nRF52 and nRF53 Bluetooth SoC’s in mind, but the company emphasizes this PMIC can serve other applications employing lithium ion or lithium polymer batteries where saving space is an essential goal. These include wearables and medical devices.

 

Physical Considerations

The nPM1100 is offered in a 2.075mm square wafer level chip scale package (WLCSP).

 

The nPM1100. Image Courtesy of the nPM1100 datasheet

 

When employed in a circuit, Nordic reports that the PCB area usage can be as low as 23 mm2 when accounting for necessary passive components.

 

Getting to Market Faster

Nordic offers the nPM1100 EK, an evaluation kit to aid engineers in evaluating the features of the nPM1100.

The nPM100 EK. Image courtesy of Nordic Semiconductor

 

The evaluation kit includes buttons to enter and exit ship mode and switches to access all the PMIC’s selectable settings. Also included are the necessary connectors for USB, batteries and for the PMIC’s pins.