Toshiba has developed Bluetooth low energy System-on-Chip (SoC) compliance with version 4.2 that reduces current to 50% that of current products for IoT devices driven by a small-sized coin cell lithium battery. By adopting an architecture configuration and analog circuit design suited to low power operation, current consumption of 3.2mA for receive (RX) and 3.5mA for transmit (TX) are achieved, considerably lengthening battery life.
The SoC also integrates RF (Radio Frequency) matching networks, reducing the number of external components and contributing to downsizing of IoT devices. This technology will be presented at the 2016 IEEE Asian Solid-State Circuits Conference (A-SSCC) in Toyama, Japan, on November 8.
In order to use various types of usable batteries in wearable IoT devices, a Bluetooth low energy SoC with low current consumption, in the range of 3-4mA, is a major requirement. Although it is effective to include external components in a Bluetooth low energy SoC to shrink the size of the Bluetooth low energy device, degradation of receiver sensitivity and transmission power of a Bluetooth low energy SoC with built-in RF matching networks remains a problem, due to loss mismatch.
Toshiba has introduced three techniques to reduce Bluetooth low energy SoC current consumption: (1) a receiver architecture configuration suitable for low current consumption; (2) a highly efficient power management system; and (3) low current RF design.
By adopting these low current techniques, Toshiba’s Bluetooth low energy SoC reduces operating current consumption, to 3.2mA for the RX and 3.5mA for the TX while improving radio performance; in the RX sensitivity is ?93 dBm and output power 0 dBm.
Furthermore, by integrating all RF matching networks in the SoC, which is fabricated with the 65 nm CMOS process, the external component count can be reduced to seven from the 19 required by Toshiba’s current product.
