HX711 Analog-to-Digital Converter: 24-Bit ADC, HX711 Datasheet, and Load Cell

HX711 is a precision 24-bit analog-to-digital converter  (ADC) designed for weighing scales and industrial control applications to interface directly with a bridge sensor.

It's designed specifically for boosting cell signals and reporting them to another microcontroller.

Grove – ADC  for  Load Cell  (HX711) is a 24-bit A/D converter specifically intended for load cells. It has a low-noise programmable amplifier on-chip with gain options of 32, 64, and 128.

The HX711 chip combines a regulated power supply, an on-chip clock oscillator, and various peripheral circuits for high integration, fast response, and good anti-interference performance.

With the Grove I2C connector and 4-pin screw terminal, it becomes quite easy to connect the load cell and microcontroller.  no soldering is required. You can build your own Arduino weigh sensor system in just a few simple steps.

HX711 Pinout

HX711 Block Diagram

• Two selectable differential input  channels   

• On-chip active low noise PGA with selectable gain of 32, 64 and 128

• On-chip power supply  regulator for load-cell  and ADC  analog power supply 

• On-chip oscillator  requiring no external component with optional external crystal

• On-chip power-on-reset

• Simple digital control and serial interface: pin-driven controls, no programming  needed

• Selectable 10SPS or 80SPS output data rate

• Simultaneous 50 and 60Hz supply rejection

• Current consumption including on-chip  analog power supply  regulator: normal operation  < 1.5mA, power down < 1uA

• Operation supply voltage range: 2.6 ~ 5.5V

• Operation temperature range: -40 ~ +85℃

• 16 pin SOP-16 package

• Weigh Scales

• Industrial Process Control

• Micro weight meter

• Kitchen Scale

HX711 PCB Schematic

A load cell is a device that measures the size of a load (either a force or a weight) and converts the force into a measured electrical output.

They serve a variety of functions, including determining the weight of an object, tracking weight changes over time, and measuring strain and load on a surface.

When a force is applied to a load cell, it transforms into a metal core with a set of electrical resistances. However, once the force is released, it reverts to its previous state. The reversibility of this substance determines the load cell's quality and accuracy.

HX711 Dimensions

Avia Semiconductor (Xiamen) Ltd. is a fabless semiconductor company founded by overseas Chinese in 2006. The company specializes in analog and mixed-signal integrated circuit design and development. Successful products include 24-bit analog-to-digital converters designed especially for weighing scale applications.

HX711 Datasheet