MEMS-Based "Sonar on a Silicon Chip" Time-of-Flight Sensor


Extending the Chirp SmartSonic platform, the CH-201 supports a maximum sensing range of 5 meters

The CH-101

TDK Corporation announces the immediate availability to select OEMs of the Chirp CH-201 MEMS-based ultrasonic Time-of-Flight (ToF) sensor with extended sensing range. This ToF sensor utilizes a tiny ultrasonic transducer chip that sends a pulse of ultrasound and then listens for echoes returning from targets in the sensor’s field-of-view. By calculating the distance based on time of flight, the sensor can determine the location of an object relative to a device and trigger a programmed behavior.

TDK’s MEMS ultrasonic technology leverages a proprietary ToF sensor in a 3.5 mm x 3.5 mm package that combines a MEMS ultrasonic transducer with a power-efficient digital signal processor (DSP) on a custom low-power, mixed-signal CMOS ASIC. The sensor handles a variety of ultrasonic signal-processing functions, enabling customers’ flexible industrial design options for a broad range of use-case scenarios including range-finding, presence/proximity sensing, object detection/avoidance and 3D position-tracking.

Following last year’s introduction of CH-101, the first commercially available MEMS-based ultrasonic ToF sensor for consumer electronics, AR/VR, robotics, drones, IoT, automotive and industrial market segments, TDK is expanding the SmartSonic MEMS ultrasonic platform. This will include the CH-201 ultrasonic ToF sensor and associated software solution for room-scale sensing applications, enabling ultralow power, always-on sensing for human presence detection without privacy concerns, among many other use cases.

TDK’s MEMS ultrasonic ToF sensor platform offers numerous advantages over optical ToF sensors:

  • Ultralow power operations for always-on sensing in battery powered devices
  • Accurate range measurement regardless of target size or color; even optically transparent targets are accurately detected
  • Immunity to ambient noise without perception by house pets
  • Ability to operate in all lighting conditions, unlike IR sensors which do not work in direct sunlight
  • Ensures eye safety, contrasting with laser-based IR ToF sensors
  • Detects objects over a customizable field-of-view up to 180°, enabling a single sensor to support room-scale sensing

The Chirp SmartSonic platform (CH-101, CH_101 module, and CH-101 developers kit) is available worldwide through distribution today. CH-201 is entering into mass production and is currently shipping to select customers.


  • 6-DoF: 6 Degrees of Freedom
  • 3D: 3 dimensional
  • AR/VR: Augmented Reality / Virtual Reality
  • Ultrasonic: Utilizing, produced by, or relating to ultrasonic waves or vibrations.

Main applications

  • Smart home and connected IoT devices
  • PC and displays
  • Robotics and drone
  • AR/VR
  • Mobile and wearable
  • Automotive and industrial

Main features and benefits:

  • Ultralow power
  • Accurate range measurement regardless of target size
  • Detects objects of any color, including optically transparent ones
  • Immunity to ambient noise
  • Works under any lighting condition
  • Expanded field of view (FoV)

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