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 contains a low distortion sine wave oscillator to drive the LVDT primary. The LVDT secondary output consists of two sine waves that drive the AD598 directly. The AD598 operates upon the two signals, dividing their difference by their sum, producing a scaled unipolar or bipolar dc output.
The AD598 uses a unique ratiometric architecture (patent pending) to eliminate several of the disadvantages associated with traditional approaches to LVDT interfacing. The benefits of this new circuit are: no adjustments are necessary, transformer null voltage and primary to secondary phase shift does not affect system accuracy, temperature stability is improved, and transducer interchangeability is improved.
Features and BenefitsLinearity: 0.05% of FS max Output Voltage: ±11 V min Gain Drift: 50 ppm/°C of FS max Offset Drift: 50 ppm/°C of FS max | AmplifiersReference Designs |
Document | note |
AD598: LVDT Signal Conditioner Data Sheet (Rev. A) | PDF 553 kB |
AD598: Military Data Sheet |
Part Number | Package | Packing Qty | Temp Range | Price 100-499 | Price 1000+ | RoHS |
---|---|---|---|---|---|---|
5962-9067101MRA Production | 20 ld Side-Brazed CerDip | OTH 19 | -55 to 125C | 87.41 | 78.67 | N |
AD598AD Production | 20 ld Side-Brazed CerDip | OTH 19 | -40 to 85C | 43.27 | 36.05 | N |
AD598JR Production | 20 ld SOIC - Wide | OTH 37 | 0 to 70C | 29.25 | 26.32 | N |
AD598JRZ Production | 20 ld SOIC - Wide | OTH 37 | 0 to 70C | 26.65 | 23.97 | Y |
AD598SD/883B Production | 20 ld Side-Brazed CerDip | OTH 19 | -55 to 125C | 90.02 | 81.03 | N |