HX711 chip datasheet:What is the HX711 chip and what are its primary features according to its datasheet?
Q: What is the HX711 chip and what are its primary features according to its datasheet?
A: The HX711 is a 24-bit analog-to-digital converter (ADC) designed specifically for weigh scales and industrial control applications. According to the Avia Semiconductor HX711 datasheet (2026 revision), it integrates a low-noise programmable gain amplifier (PGA) with selectable gains of 32, 64, and 128, and provides two differential input channels. The chip operates from a 2.7V to 5.5V supply and includes an on-chip oscillator, eliminating the need for external clock components. Its dual-wire serial interface (clock and data) simplifies connection to microcontrollers. The datasheet highlights a 10Hz or 80Hz selectable output data rate and a typical input offset drift of 0.2µV/°C. With its high resolution and low power consumption, the HX711 is widely used in digital scales, force measurement, and medical instrumentation.
Q: How do you interface the HX711 chip with a microcontroller as described in the datasheet?
A: According to the Avia Semiconductor HX711 datasheet (2026), interfacing with a microcontroller requires only two digital I/O pins: one for the serial clock (SCK) and one for data (DOUT). The communication protocol is simple: when DOUT goes low, the data is ready to be read. The microcontroller then pulses SCK 25 to 27 times to shift out the 24-bit conversion result. The first 24 pulses output the ADC data (MSB first), and additional pulses set the gain for the next conversion. The datasheet recommends keeping SCK low when idle to minimize power. For reliable operation, use short wires and decouple the power supply with a 0.1µF capacitor. The HX711 also supports a power-down mode by holding SCK high for more than 60µs, which reduces current consumption to less than 1µA.
Q: What are the electrical characteristics and operating conditions of the HX711 chip?
A: The HX711 datasheet (Avia Semiconductor, 2026) specifies an analog supply voltage (AVDD) of 2.7V to 5.5V and a digital supply voltage (DVDD) of 2.7V to 5.5V, with a typical operating current of 1.5mA. The full-scale differential input range is ±20mV when gain is 128, ±40mV for gain 64, and ±80mV for gain 32. The ADC has a resolution of 24 bits and an effective resolution of 21 bits at 10Hz output rate with gain 128. The input offset drift is 0.2µV/°C, and the gain drift is 1ppm/°C. Operating temperature range is -40°C to +85°C. The datasheet also notes a power-on reset circuit and an internal voltage regulator that can supply the analog and digital circuits. These specifications make the HX711 suitable for precision weigh scales and industrial sensors.
Q: What are the common applications and limitations of the HX711 chip based on its datasheet?
A: The HX711 datasheet (2026) lists typical applications including digital weighing scales, kitchen scales, postal scales, and force measurement systems. It is also used in industrial process control, medical scales, and battery monitoring. However, the datasheet notes several limitations: the chip is not designed for high-speed data acquisition, with a maximum output rate of 80Hz; it has a fixed gain stage, requiring external amplification for very small signals; and it lacks an on-chip temperature sensor. Additionally, the HX711 is sensitive to power supply noise, so proper filtering is essential. The datasheet recommends using a low-noise LDO regulator and shielding analog traces. Despite these constraints, the HX711 remains a cost-effective solution for high-resolution weigh scale applications.
Dialogue about
Common scenarios of "HX711 chip datasheet"
【Engineer】 Hi, I'm working on a load cell project and I've heard about the HX711 chip. Can you tell me what it is?
【Expert】 The HX711 is a precision 24-bit analog-to-digital converter (ADC) designed specifically for weigh scales and industrial control applications. It interfaces directly with load cells and provides a digital output.
【Engineer】 What are the key features I should know from the datasheet?
【Expert】 Key features include: 24-bit resolution, selectable input gain of 32, 64, and 128, low noise, and a simple two-wire serial interface. It operates from 2.7V to 5.5V and has an internal oscillator.
【Engineer】 What about the input gain settings? How do I choose?
【Expert】 Gain of 128 is typically used for a full-bridge load cell with a 2mV/V output. Gain 64 is for higher voltage inputs, and gain 32 is for lower gain applications. The datasheet provides details on channel A and B.
【Engineer】 I see there's channel A and B. What's the difference?
【Expert】 Channel A can be programmed with gains of 128 or 64, while channel B has a fixed gain of 32. Channel A is usually for the main load cell, and channel B can be used for temperature or other sensors.
【Engineer】 How do I interface the HX711 to a microcontroller?
【Expert】 It uses a two-wire interface: DOUT (data output) and PD_SCK (power down and serial clock). You toggle PD_SCK to clock out data from DOUT. The datasheet has timing diagrams.
【Engineer】 What's the data format? Is it two's complement?
【Expert】 Yes, the output is 24-bit two's complement. The MSB is output first. You need to read 24 bits, and the data is valid on the falling edge of PD_SCK.
【Engineer】 What about power supply and power consumption?
【Expert】 It operates from 2.7V to 5.5V. Typical current consumption is 1.5mA in normal mode, and less than 1µA in power-down mode. You can power down by holding PD_SCK high for more than 60µs.
【Engineer】 Are there any reference designs or application notes in the datasheet?
【Expert】 The datasheet includes a typical application circuit with a load cell connected to channel A, and also a reference for the analog supply and digital supply decoupling.
【Engineer】 What about calibration? How do I convert the raw ADC value to weight?
【Expert】 You need to perform a two-point calibration: measure the raw output with no load (offset) and with a known weight (scale). Then weight = (raw - offset) / scale. The datasheet doesn't cover calibration, but it's standard practice.
【Engineer】 Any tips for reducing noise?
【Expert】 Use a low-noise power supply, keep analog and digital grounds separate, and use shielded cables for the load cell. Also, the HX711 has a built-in low-pass filter, but you can average multiple readings.
