Features and Benefits
- Single Chip Solution, Contains Internal Oscillator and Voltage Reference
- No Adjustments Required
- Insensitive to Transducer Null Voltage
- Insensitive to Primary to Secondary Phase Shifts
- DC Output Proportional to Position
- 20 Hz to 20 kHz Frequency Range
- Single or Dual Supply Operation
- Unipolar or Bipolar Output
- Will Operate a Remote LVDT at Up to 300 Feet
- Position Output Can Drive Up to 1000 Feet of Cable
- Will Also Interface to an RVDT
- Outstanding Performance
Linearity: 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
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.
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Reference Designs (1)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.