AD670SD/883B

The AD670 is a complete single-chip 8-bit signal conditioning analog-to-digital converter consisting of an instrumentation amplifier front-end, DAC, comparator, successive approximation register (SAR), a precision reference source, and a three-state output buffer. It interfaces analog systems with 8-bit data buses with full accuracy without the need for external components or user adjustments. The AD670 is powered from a +5 V system supply. The input stage provides differential inputs with excellent common-mode rejection and can interface directly with a wide range of sensors.

The device is configured with an input adjustment resistor and supports two input ranges: 0 mV to 255 mV (1 mV/LSB) and 0 V to 2.55 V (10 mV/LSB). Within these ranges, the AD670 can be configured as either a unipolar input or a bipolar input. The differential input and common-mode rejection of this front-end are beneficial for applications such as converting sensor signals superimposed on common-mode voltages.

AD670 adopts advanced circuit design and proven processing technology. The successive approximation function is implemented through I2L (Integrated Injection Logic). The stability provided by thin-film SiCr resistors ensures no code loss over the entire operating temperature range, and laser wafer adjustment of the resistor ladder calibrates the device to an accuracy of within ±1 LSB. Therefore, users do not need to make adjustments to gain or offset. The conversion time is 10 μs.