The package measures only just 2.48 x 2.46mm. The WLCSP SoC has been developed for two-layer PCB designs. Two layer PCB designs are much cheaper than four-layer PCBs and cut costs for small, budget-conscious designs. The SoC can provide Bluetooth LE high-throughput 2 Mbps and enhanced Channel Selection Algorithm #2 (CSA #2) for improved coexistence.
The nRF52805 is based around a 64-MHz 32-bit Arm Cortex-M4 MCU (144 CoreMark) with high efficiency (65 CoreMark/mA) and supported by 192KB flash and 24KB RAM. The multiprotocol (Bluetooth LE/2.4GHz) radio provides up to +4dBm power output and -97dBm sensitivity (1 Mbps Bluetooth LE) to give a link budget of 101dBm. The radio has a peak power draw of 4.6mA (TX 0dBM, RX 1Mbps) and the SoC's current draw is down to 0.3µA in System OFF and 1.1µA in System ON with 24KB RAM retained and RTC running. The SoC also has a range of analog and digital interfaces such as SPI, UART, and TWI, a two-channel 12-bit ADC, and ten GPIOs. Nordic provides a 9.5 x 8.8mm reference layout that has all ten GPIOs available, and needs only ten external passive components (including two crystal load capacitors). The SoC is powered from a supply voltage of between 1.7 to 3.6V supply and integrates LDO and DC/DC voltage regulators.
The nRF52805 is supported by the S112 SoftDevice, with S113 SoftDevice support following soon. The S112 and S113 SoftDevices (Bluetooth 5.1-qualified protocol software) are memory-optimized peripheral "stacks" that support high-throughput 2 Mbps and CSA #2 features. The stacks support up to four connections as a Peripheral concurrently with a Broadcaster. The number of connections and bandwidth per connection is configurable. Both the S112 and S113 also have LE Secure connection support, improving security compared to LE Legacy Pairing. S113 also supports LE Data Packet Length Extension, resulting in higher throughput and less overhead per packet.