AD598: LVDT Signal Conditioner

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.

AD598 特点

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

AD598 功能框图

AD598 芯片订购指南

产品型号	产品状态	封装	引脚	温度范围
5962-9067101MRA	量产	20 ld CerDIP	20	军用
AD598AD	量产	20 ld Side-Brazed CerDip	20	工业
AD598JR	量产	20 ld SOIC - Wide	20	商业
AD598JRZ	量产	20 ld SOIC - Wide	20	商业
AD598SD/883B	量产	20 ld Side-Brazed CerDip	20	军用