The nRF7002 Expansion Board (EB) can be powered from two different options.
The power options are:
- Printed Circuit Board (PCB) edge connector (VBAT on pin 14 and VIO on pin 3)
- Castellated holes (VBAT on edge hole 10 and VIO on edge hole 12)
The following figures show the power option pins.
Figure 1. PCB edge connector with VIO on pin 3, front view
Figure 2. PCB edge connector with VBAT on pin 14 and GND on pin 20, back view
Figure 3. Castellated holes with VBAT on edge hole 10 and VIO on edge hole 12, front view
The following table shows the voltage supply ranges for VBAT and VIO.
| Supply domain | Voltage supply range |
|---|---|
| VBAT | 2.9 V to 4.5 V |
| VIO | 1.8 V to 3.3 V |
The BUCKEN signal going to the BUCKEN pin on nRF7002 is connected through a Resistor-Capacitor (RC) circuit to the control signal of a load switch (U4) as shown in the figure below. This ensures proper start-up of nRF7002, which requires that the VDDIO domain is powered a minimum of 1 ms after the rising edge of the BUCKEN signal.
Figure 4. BUCKEN VDDIO timing circuit
