# HX711 Analog Digital Converter (ADC) ### Overview The Boardoza HX711 is a precision 24-bit analog-to-digital converter designed specifically for weigh scales and industrial control applications to interface directly with a bridge sensor. Built around the Avia Semiconductor HX711 architecture, this module integrates a low-noise programmable gain amplifier (PGA) and a regulated power supply, providing a complete "front-end" solution for load cells. Unlike general-purpose ADCs, the HX711 is optimized for small-signal differential measurements. It eliminates the need for external active components by incorporating on-chip power supply regulators and an on-chip oscillator, drastically reducing the bill of materials and PCB footprint for high-precision force sensing systems. *** | Front Side | Back Side | | :-----------------------------------------------------------------------------------------------------------------------------: | :---------------------------------------------------------------------------------------------------------------------------: | | ![HX711 Front](https://github.com/Boardoza/Boardoza_HX711_Load_Cell_Amplifier_Breakout_Board/raw/main/assets/HX711%20Front.png) | ![HX711 Back](https://github.com/Boardoza/Boardoza_HX711_Load_Cell_Amplifier_Breakout_Board/raw/main/assets/HX711%20Back.png) |

*** ### Core Technical Specifications The module is defined by the following operational parameters: * Resolution: 24-bit output precision, capable of resolving extremely minute voltage changes typical of strain gauge bridges. * Input Channels: Features two selectable differential input channels (Channel A and Channel B). Channel A is programmable with a gain of 64 or 128, while Channel B has a fixed gain of 32. * Low-Noise PGA: The integrated Programmable Gain Amplifier enables direct interfacing with low-output sensors (e.g., 2mV/V load cells) without requiring external instrumentation amplifiers. * Data Rate: User-selectable output data rate of either 10 samples per second (SPS) for high stability or 80 SPS for faster response times. * Power Supply Rejection: Simultaneous 50Hz and 60Hz supply rejection ensures measurement stability in electrically noisy industrial environments. * Operating Voltage: Supports a wide supply range from 2.6V to 5.5V, making it compatible with both 3.3V and 5V logic systems. * Current Consumption: Low operating current (<1.5 mA) and an integrated power-down mode (<1 µA) suitable for battery-powered scales. *** ### Key Engineering Features #### Specialized Bridge Interface The module is engineered to drive Wheatstone bridge sensors directly. It provides the excitation voltage (E+ and E-) and reads the differential signal voltage (A+ and A-). The on-chip analog power regulator simplifies the power distribution network, ensuring that the excitation voltage remains stable relative to the ADC reference, which is critical for ratiometric measurement accuracy. #### Digital Interface Protocol The HX711 utilizes a custom two-wire serial interface (Clock and Data) that is similar to, but not compatible with, standard SPI. This "bit-banging" protocol allows the host microcontroller to retrieve the 24-bit conversion result and simultaneously configure the gain and channel selection for the *next* conversion cycle via the number of clock pulses sent. #### On-Chip Oscillator The internal on-chip oscillator requires no external crystal or capacitor, simplifying board layout and reducing susceptibility to EMI. This robust clock generation ensures consistent timing for the Sigma-Delta modulator and digital filter stages. *** ### Board Pinout #### J1 Connector

Pin Number	Pin Name	Description
1	VCC	2.7V - 5.5V Power Input
2	VDD	2.7V - 5.5V Power Input
3	DAT	Serial Data Output
4	CLK	Serial Clock Input
5	GND	Ground

#### J2 Connector

Pin Number	Pin Name	Description
1	B+	Positive Signal (Second Channel)
2	B-	Negative Signal (Second Channel)

#### J3 Connector (Load Cell Interface)

Pin Number	Pin Name	Description
1	RED/E+	+ Excitation
2	BLK/E-	- Excitation
3	WHT/A-	- Signal
4	GRN/A+	+ Signal

#### JP1 Jumper Settings

Pin Configuration	Data Rate
1-2	80 Samples per Second (SPS)
2-3	10 Samples per Second (SPS)

*** ### Applications * Electronic Scales: Kitchen scales, bathroom scales, and postage meters. * Industrial Weighing: Hopper scales, platform scales, and conveyor belt monitoring. * Force Sensing: Strain gauge measurement for structural health monitoring. * Tactile Sensors: Robotics pressure sensing and grip force feedback. *** ### Board Dimensions: ![HX711 Dimension](https://github.com/Boardoza/Boardoza_HX711_Load_Cell_Amplifier_Breakout_Board/raw/main/assets/HX711%20Dimension.png) *** {% hint style="info" %} Ready to integrate? You can purchase the **HX711 Analog Digital Converter** directly from our [Online Store](https://www.robotshop.com/products/acrome-load-cell-amplifier-board-hx711?qd=97fe14d7a62dbe4d77087959586fffc1). Worldwide shipping is available for engineering samples and production batches. {% endhint %} --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.acrome.net/smd-applications/boardoza-sensors/hx711-analog-digital-converter-adc.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.