Bluetooth chip is only 4- x 4-mm

March 07, 2017 // By Julien Happich
Part of the Swatch group, EM Microelectronic announced what the company believes to be the world's smallest Bluetooth chip. Offered in a 4- x 4-mm QFN-28 package, in a WLCSP-21 or as a bare-die, the EM9304 is optimized for Bluetooth v4.2 low energy enabled products.

Built around an ARC EM4, 32-bit MCU running at 24 MHz, the flexible architecture of the EM9304 allows it to act as a companion IC to any ASIC or MCU-based product, or as a complete SoC. Custom applications can execute from the 128kB of one-time-programmable (OTP) memory, and digital peripherals (SPI or I2C) can be used to interface with external devices such as sensors, memory, display, or touch drivers. A floating point unit can be exploited to implement advanced algorithms such as sensor fusion. Included in the 136kB ROM is a Bluetooth v4.2 link layer with a Host Controller Interface (HCI), a Bluetooth v4.2 stack with proprietary Application Controller Interface (ACI), several profiles, and over-the-air firmware (FOTA) updating routines.

The Bluetooth low energy controller and host can be configured to support up to eight simultaneous connections. Secure connections and extended packet length are also supported per the Bluetooth v4.2 standard. On-chip power management supports automatic configuration for 1.5V or 3V batteries. Current consumption is minimized for all modes of the application utilizing an efficient scheduler and memory manager. The chip draws 3.5mA typical of peak receiver current, 5.5mA typical peak transmitter current at 0 dBm, and 0.9μA in connected sleep mode, 0.05μA in disable mode. For secure communications are also integrated in the chip a True Random Number Generator and an AES-128 Hardware Encryption Engine.