How long do I have to keep the Sterling-LWB5+ in RESET?

The absolute minimum the Power On Reset shall be asserted is 150ms after the power supply is stable and the WL_REG_ON and/or BT_REG_ON signal are asserted.

However we recommend waiting 250 milliseconds to ensure the internal reset sequence has completed.

Note: The signals WL_REG_ON and BT_REG_ON are pulled high by default internally for the Wi-Fi and Bluetooth radios to be enabled when power is applied.