The BLE advertisement is a fundamental function of Bluetooth® Low Energy. Basically, a BLE device sleeps and periodically wakes up to transmit a BLE advertisement packet, followed by a receive pulse on the three primary channels, #37, #38, and #39 dedicated for BLE advertisements. This is called a “connectable advertisement”. Or, a BLE device can perform a transmit-only advertisement on the three primary channels, called a “non-connectable advertisement”; then the BLE device goes back to sleep again until its next wake event. The advertisement interval is the relative timing between successive wake pulses. BLE devices can reduce their advertisement wake time by storing parameters in memory during the sleep time. This is referred to as “memory retention”. The trade-off for implementing memory retention during sleep time is that the sleep current increases. The RSL15 differentiates itself from the competition by consuming only 150 nA of sleep current with 8 kB memory retention, and 288 nA with 32 kB memory retention. An advertisement interval of every 2.5 seconds will exhibit shorter battery life than an advertisement of every five seconds. This is because when using the RSL15, the sleep current is only 200 to 300 nA.