The AD598 is a complete, monolithic Linear Variable Differential Transformer (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 AD598 converts the raw LVDT secondary output to a scaled dc signal. The device can also be used with RVDT transducers.
The AD598 provides a complete solution for conditioning linear variable differential transformer (LVDT) and rotary variable differential transformer (RVDT) signals. It includes an internal oscillator and voltage reference, requires no external adjustments, and can operate from single or dual supplies with either unipolar or bipolar output. The device can drive long cable runs up to 1000 ft and operate remote transducers up to 300 ft.
Key specifications include a linearity of 0.05 % FS, gain drift of 50 ppm/°C, offset drift of 50 ppm/°C, and a frequency range of 20 Hz to 20 kHz. The datasheet contains functional block diagrams, design procedures, half‑bridge operation details, and package dimensions for the 20‑pin DIP version.
| Linearity | 0.05 % of FS max |
|---|---|
| Output Voltage (minimum) | +11 V |
| Gain Drift | 50 ppm/°C of FS max |
| Offset Drift | 50 ppm/°C of FS max |
| Frequency Range | 20 Hz to 20 kHz |
The AD598 provides a minimum output voltage of +11 V.
The device achieves a linearity of 0.05 % of full scale maximum.
The gain drift is specified as 50 ppm per degree Celsius of full scale maximum.
It operates from 20 Hz up to 20 kHz.