The nPM1300 Evaluation Kit (EK) has a flexible and configurable power supply system to allow testing with different power sources and to facilitate accurate power measurements.
The power supply to the nPM1300 Power Management Integrated Circuit (PMIC) is from Universal Serial Bus (USB) (VBUS) or battery (VBAT). The input voltage ranges from 2.3 V to 5.5 V, depending on the source.
USB power is the main input source and the source for battery charging. A compatible battery connected to the EK acts as a complementary power source. The battery powers the EK if no external power source is connected to USB PMIC on J3, or VBUS on P2.
The USB-C connector, nPM CONTROLLER on J4, powers the nPM Controller and its circuitry when evaluating the PMIC in the nPM PowerUP computer app.
The following figure shows the power supply options for the nPM1300 EK.
The following table shows the alternatives for connecting the main and complementary power input sources on the EK.
| Input source | Part | Connector type | Comment | |
|---|---|---|---|---|
|
Main |
VBUS 4.0 V to 5.5 V |
J3 | USB-C | Only USB power on this connector |
| P2 | Pin header | VBUS on pin 1 | ||
|
Complimentary |
VBAT 2.3 V to 4.45 V |
J1 | JST SM02B header (2 pins) | Battery without Negative Temperature Coefficient (NTC) thermistor, ground on pin 1 |
| J2 | JST SM03B header (3 pins) | Battery with NTC thermistor, ground on pin 1 | ||
| P1 | Pin header | VBAT on pin 3 | ||
- To keep the operating temperature of the EK within safe limits the recommended input current on VBUS is 1 A.
- The maximum allowed input current on VBUS is determined by the power delivery negotiation between host and PMIC.
- Pay attention to the polarity of the battery connectors (J1/J2). Connecting the polarity the wrong way causes the device to become very hot. The nPM1300 EK uses JST configuration B, where pin 1 is GND.
- A battery without an NTC thermistor requires an external resistor to be terminated to GND on the NTC pin on pin header P3.
