AD698SQ

AD698 is a complete, monolithic LVDT signal conditioning subsystem. It is used in conjunction with LVDTs to convert transducer mechanical position to a unipolar or bipolar DC voltage with a high degree of accuracy and repeatability. All circuit functions are included on the chip. With the addition of a few external passive components to set frequency and gain, the AD698 converts the raw LVDT output to a scaled DC signal. The device will operate with half-bridge LVDTs, LVDTs connected in the series op-posed configuration (4-wire), and RVDTs. The AD698 contains a low distortion sine wave oscillator to drive the LVDT primary. Two synchronous demodulation channels of the AD698 are used to detect primary and secondary amplitude. The part divides the output of the secondary by the amplitude of the primary and multiplies by a scale factor. This eliminates scale factor errors due to drift in the amplitude of the primary drive, improving temperature performance and stability.

• Single chip solution, contains internal oscillator and voltage reference
• No adjustments required
• Interfaces to half-bridge, 4-Wire LVDT
• DC output proportional to position and unipolar or bipolar output
• 20Hz to 20KHz frequency range
• Will also decode AC bridge signals
• Outstanding performance: nonlinearity TMIN to TMAX: ±500ppm of FS max, output voltage: ±11V min
• Gain drift: ±20ppm/°C of FS (typ) and offset drift: 5ppm/°C of FS (typ)
• 24 lead DIP package
• Operating temperature range from -55 to 125°C

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party