On a Qorvo PCB/module, pins labeled VDD, GND, and VPD are standard power/control connections, but each has a specific role:
1. VDD (Supply Voltage)
- This is the positive power supply input.
- It provides the operating voltage for the device (e.g. +3.3 V, +5 V depending on the part).
- Think of it as the “live” rail powering the circuitry.
2. GND (Ground)
- This is the 0 V reference point.
- All voltages (including VDD and signals) are measured relative to this.
- It completes the electrical circuit.
3. VPD (Power-Down Control / Bias Control)
- This one is device-specific, but on Qorvo RF parts it typically means:
- Power-Down (enable/disable) pin, or
- Voltage for Power Detector / bias control
Most commonly:
- Low (0 V) → device off / disabled
- High (e.g. tied to VDD) → device on / active
But in some RF amplifiers:
- VPD may control bias current, affecting gain or efficiency.
Practical example (typical RF amplifier use)
- VDD → +5 V supply
- GND → ground plane
- VPD → tied to VDD (always on) or driven by a GPIO for switching
Important tip
Always check the specific Qorvo part datasheet, because:
- VPD behavior (logic vs analog control) varies
- Voltage limits on VPD can be different from VDD