VL53L0X : Pin Configuration, Circuit Diagram and Applications

Sensors are the most important catalyst for the evolution of automation. With the increase in technology, today there are both Analog and Digital sensors available for various applications. The development of sensors has many automation tasks easier. Today there are sensors to measure temperature, to measure light intensity, to measure humidity, to measure sound, to measure radiation, to measure proximity, etc… For measuring the distance range of an object, there are various types of distance sensors available in the market. Some use Laser beams for operation whereas some use LED. One such sensor which uses the Laser beam for measuring distance range is VL53L0X IC.

What is VL53L0X?

VL53L0X is a LIDAR based distance measuring sensor that uses the Time of flight principle to operate. This device is very small and can be easily interfaced with microcontrollers.

Working Principle

VL53L0X is a laser ranging sensor. It uses the Time of flight principle for measuring the distance of the objects. Here a laser beam is released from the Vertical Cavity Surface Emitting Laser present in the device. This beam stricks the surface of the object and bounces back. The time taken by the laser beam to strick the surface of the object and reflect back to the sensor is known as the Time of flight. This time is measured to calculate the distance between the object and the sensor. To measure the photon timing and photon distance SPAD array is used in the device. This also increases the accuracy of the device. VL53L0X can measure the distance range of the object even if its surface is highly reflective.

Pin Configuration

The VL53L0X distance sensor is provided by ST Microelectronics is available as a 12-Pin IC. The pin description of the IC is as given below –

• Pin -1 AVDDVCSEL  is the power supply pin to VCSEL which is connected to the main supply. A voltage of 2.6V to 5.5V is supplied to this pin.
• Pin-2  is the VCSEL ground pin -AVSSVCSEL. This pin is connected to the main ground.
• Pin-3 is the ground pin of IC- GND.
• Pin-4 is also the ground pin GND2.
• Pin-5 is the digital input Xshutdown pin -XSHUT.
• Pin-6 is the ground pin -GND3,
• Pin-7 is the interrupt output pin-GPIO1. This is a digital output pin.
• Pin-8 is the do not connect pin-DNC. This pin is left floating
• Pin-9 is the I2C Serial Data pin- SDA. This is a digital input/output pin.
• Pin-10 is the I2C serial clock input pin – SCL. This is a digital input pin.
• Pin-11 is the supply voltage pin- AVDD.
• Pin-12 is the ground pin- GND4. This pin should be connected to the main ground.

Block Diagram

With the help of API, many high-level functions of VL53L0X  can be controlled by the Host. Initialization, Calibration, Choice of accuracy, Choice of ranging mode, start/stop, etc… of VL53L0X can be controlled by the API commands.

This API can be compiled on any platform. The API contains 3 ranging modes – single ranging, Continuous ranging, and Timed ranging. In single ranging mode, ranging is done after the API function is called. Here ranging is done only once.

In continuous ranging, ranging is done continuously after calling the API function. Here to return to SW standby mode, the user has to stop the ranging. In timed ranging, ranging is done continuously after calling the API function but after each measurement, the another starts after a user-defined delay.

Circuit Diagram

During interfacing VL53L0X  with microcontrollers, external capacitors and resistors are used. External capacitors used with the main supply voltage pin AVDD should be placed as close as possible to AVDDVCSEL and AVDDVCSEL pin to reduce noise and interference.

1.5kΩ to 2kΩ external pull-up resistors are recommended for the AVDD of 2.8V. For XSHUT and GPIO1 10kΩ is the recommended pull-up resistor value. A host has an API through which VL53L0X is controlled using commands.

Specifications of VL53L0X

Some of the specifications of VL53L0X  are listed below –

• The operating voltage range for this device is 2.6V to 3.5V
• This device needs a supply current of 10mA for operation.
• To communicate with the microcontroller, the I2C communication protocol is provided onboard.
• This device can measure the target distance of up to 2 meters.
• A 2.8V linear voltage regulator is provided.
• Single-Photon Avalanche Diodes array is used in the device.
• A 980nm Vertical Cavity Surface Emitting Laser is used for laser ranging.
• This device also has an Integrated level shifter.
• This device has immunity to the ambiance.
•  To give good prevention from glass optical crosstalk, Integrated IR filters are provided.
• The operating temperature range is from -20°C to  70°C.
• This device is available as an Optical LGA12 package.
• VL53L0X can be controlled using an API.
• Using API many high-end applications can be designed by the customer easily.
• This API contains 3 ranging modes to control the functioning of VL53L0X.

Applications of VL53L0X

VL53L0X is a laser ranging module. This sensor became popular when it was first used in the iphone7 and other Apple phones for 3D images. There are various applications of this module. Some of them are listed below –

• VL53L0X is used in robotics for obstacle detection and avoidance.
• In many of the latest Mobile Smartphones, this module is used as a proximity sensor.
• Used for medical imagery where images have to be taken in low-light conditions.
• In cameras, for autofocus, VL53L0X is used.
• To capture the image of fast-moving objects and increase the performance of the camera VL53L0X is used in modern cameras.
• For one-dimensional gesture recognition, this module is used.
• In automatic faucets, soap dispensers, and automatic taps, to detect the hand gestures, VL53L0X is applied.
• This module is also used in computers and laptops for user detection.

Alternative IC

Besides the VL53L0X sensor provided by ST Microelectronics, some of the other IC that can be used as an alternative to this module are VL6180, Ultrasonic Sensor HC-SR04.

The laser used in this sensor is invisible and is not harmful to the human eye. VL53L0X is also popularly named as the world’s smallest distance measuring sensor. Further details on the electrical characteristics of this sensor can be found in its Datasheet.  Does your smartphone use VL53L0X for autofocus of camera lens?