TI states that its BAW technology consists of a piezoelectric material sandwiched between two electrodes. The material is typically aluminium-nitride although TI has not disclosed its material. When put under electrical load the piezo material absorbs some energy as mechanical vibration producing reliable precision oscillations as the reference for a high-frequency stable clock.
TI has used this to produce a wireless microcontroller – the SimpleLink CC2652RB – that needs no external clock and therefore saves board area and bill of material cost. The second development – the LMK05318 – is a single-channel network synchronizer clock for 400-Gbps networks.
The CC2652RB is a Cortex-M4F microcontroller with a 2.4GHz transceiver compatible with Bluetooth 5 lowe energy and IEEE 802.15.4 PHY and MAC supporting ZigBee and Thread. The BAW included in the package supports the clock frequency of up to 48GHz and the RF section. The CC2652RB works in the full -40°C to 85°C temperature range, unlike many crystal-based solutions currently on the market, TI said.
The LMK05318 network synchronizer clock provides jitter cleaning and clock generation to meet the timing requirements of communications infrastructure and industrial applications. The ultra- low jitter and high power supply noise rejection (PSNR) of the device can reduce bit error rates (BER) in high-speed serial links. The device can generate output clocks with 50fs RMS jitter using the BAW-based voltage-controlled oscillator.
Texas Instruments is not the first company to develop BAW resonators.
Akoustis Technologies Inc. (Charlotte, North Carolina) has introduced 5.2GHz BAW RF filter for tri-band WiFi routers and a 3.8GHz BAW RF filter targeting radar applications. Akoustis also operates a MEMS foundry with 26,000 square feet of cleanroom for processing 150mm-diameter wafers just outside Rochester, New York. This facility is complemented by an 8,000-square-foot MEMS and optoelectronic packaging facility on the same site.
Qualtre Inc. (Marlborough, Mass), is a developer of MEMS motion sensors based on BAW and has produced BAW-enabled MEMS gyroscopes and single-axis angular rate (rotational) sensors designed for harsh environments.
Preproduction samples of the CC2652RB wireless MCU are available in a 7mm by 7mm very thin QFN (VQFN) package. Pricing starts at US$3.55 in 1,000-unit quantities. The LMK05318 high frequency clock and jitter cleaner is available in production quantities in a 48-pin, 7mm by 7mm VQFN package. Pricing starts at US$11.44 in 1,000-unit quantities.
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