The AD7780 is a complete low-power front-end solution for bridge sensor products, including scales, strain gauges and pressure sensors. It consists of a high-precision, low-power, 24-bit sigmadelta (Sigmad-δ) ADC; Low noise programmable gain amplifier (PGA) on chip; And an on-chip oscillator. With a power consumption of only 330μA, the AD7780 is particularly suitable for portable or battery-powered products requiring extremely low power consumption.
Functional block diagram
The AD7780 also has a power off mode that allows users to turn off power to the bridge sensor and power the AD7780 off when not converted, thereby increasing the battery life of the product. For ease of use, all functions of the AD7780 are controlled by dedicated pins. Eight status bits are appended to the 24-bit transition each time a data read occurs. These status bits contain a sequence of patterns that can be used to confirm the validity of the serial transmission. The on-chip PGA has a gain of 1 or 128 and supports a full scale differential input of ±5 V or ±39 mV.
The device has two filter response options. The response of the filter at the 16.7 Hz update rate provides superior dynamic performance. At this update rate, the settling time is 120 ms. At a 10 Hz update rate, the filter response provides stopband attenuation greater than −45 dB. In load cell applications, this stopband suppression helps to suppress low frequency mechanical vibration of the load cell. At this update rate, the settling time is 300 milliseconds.
At the update rates of 10 Hz and 16.7 Hz, 50 Hz/60 Hz suppression occurs simultaneously. The AD7780 operates with a power supply of 2.7V to 5.25V. It is available in narrow-body, 14-lead SOIC package and 16-lead TSSOP package.
Overall dimension
