Current measurements

The nPM2100 EK can be set up to monitor current flowing into the nPM2100 Power Management Integrated Circuit (PMIC), from the battery, and into the external application.

Current can be measured using any of the following test instruments.

Power Profiler Kit II (PPK2)
Oscilloscope
Ampere meter
Power analyzer
Source Measure Unit (SMU)

For higher precision results, using an SMU is recommended. The PPK2 is an affordable alternative to an SMU because it captures traces of both voltage and current changes.

The main power supply for the nPM2100 PMIC is VBAT. The complementary power supply is VEXT. The PMIC regulated output is VOUT.

Table 1. Components for current measurement
Component	VBAT	VEXT	VOUT
Measurement connector	P6, pin 2 and pin 3	P6, pin 2 and pin 3	P9, pin 1 or pin 2 or VOUT probe loop
Series resistor	R1 (IBAT)	R1 (IBAT)	External
Series resistor range	≤1 Ω	≤1 Ω	≤1 Ω

Note: If resistor R1 is still mounted after measuring current and an external power source is connected, do not add a jumper to P6. This would connect VBAT or VEXT to the external power source output and potentially damage the EK or the power source.

The nPM2100 EK has a default jumper configuration described in Jumpers and switches. To ensure that the EK operates correctly without modifications, verify the jumper settings before powering up the EK. Before conducting measurements, connect the EK to a DC power source (VBUS) as described in the Power supply.

For more information on current measurement, see the tutorial Current measurement guide: Introduction.