HX711 Bridge Sensor Digital Interface Module

Description

A very low cost module incorporating with a very high precision 24 ADC and differential high gain inputs designed to be interfaced with many common types of bridge sensors. E.g. pressure, strain, weight sensors.

Based on Avia Semiconductor’s patented technology, HX711 is a precision 24-bit analogue to-digital converter (ADC) designed for weigh scales and industrial control applications to interface directly with a bridge sensor. The input multiplexer selects either Channel A or B differential input to the low-noise programmable gain amplifier (PGA). Channel A can be programmed with a gain of 128 or 64, corresponding to a full-scale differential input voltage of ±20mV or ±40mV respectively, when a 5V supply is connected to AVDD analogue power supply pin. Channel B has a fixed gain of 32. On-chip power supply regulator eliminates the need for an external supply regulator to provide analogue power for the ADC and the sensor. There is no programming needed for the internal registers. All controls to the HX711 are through the pins.

Features:

• 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 analogue 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
• Simultaneous 50 and 60Hz supply rejection
• Current consumption including on-chip analogue power supply regulator: normal operation < 1.5mA, power down < 1uA
• Operation supply voltage range: 2.6 ~ 5.5V
• Operation temperature range: -40 ~ +85oC