Sum and Difference Amplifier Modules

Position Sensing Modules

QD7-0-SD or QD50-0-SD are quadrant photodiode arrays with associated circuitry to provide two difference signals and a sum signal. The two difference signals are voltage analogs of the relative intensity difference of the light sensed by opposing pairs of the photodiode quadrant elements. In addition the amplified sum of all 4 quadrant elements is provided as the sum signal. This makes the QD7-0-SD or QD50-0-SD ideal for both light beam nulling and position applications. Very precise light beam alignments are possible, and the circuit can also be used for target acquisition and alignment.

Please note that the QD50-0 and QD7-0 model numbers refer to the stand alone quadrant photodiodes. To order to complete Sum and Difference modules please use the following models number: QD50-0-SD and QD7-0-SD for the 50mm2 and 7mm2 version respectively.

Sum and Difference Amplifier Module

Product Applications

  • Position Measuring
  • Beam Centering
  • Targeting
  • Guidance Systems

Product Features

  • A 10┬Ám gap is available for the QD50-SD Modules
  • Other QD7-XX or QD50-XX are available upon request

Position Sensing Modules

Model Number Active Area Active Area Dimensions Element Gap Responsivity Capacitance Dark Current NEP Reverse Voltage Rise Time Package Click Image to Zoom
QD7-0 7 mm² 3.0 Φ mm ‡ 0.2 mm 0.54 A/W 20 pF 4 nA 9.0 e-14 30 V 10 ns 41 / TO-5 No image found for (QD7-0)
QD50-0 50 mm² 8.0 Φ mm ‡ 0.2 mm 0.54 A/W 125 pF 15 nA 1.3 e-13 30 V 10 ns 73 / TO-8 No image found for (QD50-0)

Position Sensing Modules

Model Number Operating Temp Storage Temp Package Click Image to Zoom
QD7-0 -40 ~ +100 -55 ~ +125 41 / TO-5 No image found for (QD7-0)
QD50-0 -40 ~ +100 -55 ~ +125 73 / TO-8 No image found for (QD50-0)