nPM1100 EK v0.8.0

Measuring current

The nPM1100 EK supports the monitoring of current flowing into the Power Management Integrated Circuit (PMIC), to and from the battery, and into the external application .

Note: The battery charger includes automatic trickle charge control which introduces restrictions on what current measurement instruments can be used with VBAT.

Current can be measured using various test instruments. Some examples of test equipment are the following:

The nPM1100 PMIC primary power supply is from VBUS. The secondary power supply as well as charger output is VBAT.

The nPM1100 PMIC primary output is VOUTB.

Table 1. Components for current measurement
Component VBUS VBAT VOUTB
Measurement connector P8, pin 1 P4, pins 1 and 2 P4, pin 3
Solder bridge SB3 SB4  
Series resistor R1 R20  
Series resistor range <100 mΩ <100 mΩ  
Directionality Unidirectional Bidirectional Unidirectional

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