Single Chip Solution, Contains Internal Oscillator and
Voltage Reference
No Adjustments Required
Interfaces to Half-Bridge, 4-Wire LVDT
DC Output Proportional to Position
20 Hz to 20 kHz Frequency Range
Unipolar or Bipolar Output
Will Also Decode AC Bridge Signals
Outstanding Performance
Linearity: 0.05%
Output Voltage: 611 V
Gain Drift: 20 ppm/8C (typ)
Offset Drift: 5 ppm/8C (typ)
The AD698 is a complete, monolithic Linear Variable Differen- tial Transformer (LVDT) signal conditioning subsystem. It is used in conjunction with LVDTs to convert transducer mechan- ical position to a unipolar or bipolar dc voltage with a high de- gree 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 second- ary 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. The AD698 uses a unique ratiometric architecture to eliminate several of the disadvantages associated with traditional ap- proaches to LVDT interfacing. The benefits of this new cir- cuit are: no adjustments are necessary; temperature stability is improved; and transducer interchangeability is improved. The AD698 is available in two performance grades: Grade Temperature Range Package AD698AP –40°C to +85°C 28-Pin PLCC AD698SQ –55°C to +125°C 24-Pin Cerdip
Specifications
Bandwidth:
20kHz
Supply Voltage Min:
13V
Supply Voltage Max:
36V
Amplifier Case Style:
LCC
No. of Pins:
28Pins
Operating Temperature Min:
-40°C
Operating Temperature Max:
85°C
Product Range:
-
Automotive Qualification Standard:
-
RoHS Phthalates Compliant:
Yes
MSL:
MSL 3 - 168 hours
SVHC:
No SVHC (07-Jul-2017)
Alternate Descriptions
RS Components
Universal LVDT Signal Conditioner
Transfer Multisort Elektronik
Integrated circuit: LVDT signal conditioner; LVDT; PLCC28
Richardson RFPD
AMPLIFIER - SPECIAL PURPOSE
RS Components UK
Universal LVDT Signal Conditioner
RS Components DE
Differenzverstärker AD698APZ, 17,5 V PLCC 28-Pin Versorgungsspannung bipolar typ. : 13V Montage-Typ : SMD Abmessungen : 11.58 x 11.58 x 3.94mm Länge : 11.58mm Betriebstemperatur max. : +85 °C Betriebstemperatur min. : -40 °C, Analog Devices
