The OT-301SL - Position Sensing Amplifier For Single Axis PSD

OT-301SL Position Sensing Amplifier

OT-301SL General Description

The OT-301SL printed circuit board amplifier is designed for direct integration into OEM instrumentation. Optimized for single-axis Position Sensing Detectors (PSDs) with selectable bias voltages and three gain ranges, the OT-301SL's circuit elements add, subtract and divide signals with exceptional accuracy.

Precision op amps and resistor networks perform addition and subtraction operations; optimized analog dividers provide the final ratio. The analog divider ensures the utmost in linearity over a very wide signal range.

Features

  • Analog Position Output Voltage
  • Sum Output
  • Wide Dynamic Range - Three Decades 103V/A, 104V/A, 105V/A
  • DC to 15kHz
  • Calibration Adjust
  • Zero Offset Adjust
  • Automatic Detector Bias
  • Position Independent of Beam Intensity


The final stages provide ±10% reading adjustment of the position output and serve as a high performance output buffer for driving long cables. The sum signal equals the total detector signal and is proportional to the incident beam power.

The OT-301SL includes a DC-DC converter that can be removed and replaced with an external power source for reducing cost in high-volume OEM applications.

Beam position is calculated from the ratios of signals generated by the PSD's two anode connections (designated Y1 and Y2). Dual transimpedance amplifiers on the OT-301SL accurately measure the PSD's anode signal currents. The exact relationship between PSD signal and beam position is as follows: the total detector signal and is proportional to the incident beam power.

ot301sl-b

where Y is the coordinate of the centroid of the beam spot on the PSD surface (measured from the detector center); and L is the size of the detector's sensitive surface in mm (e.g.: 2.5, 5.0, 10, 20, 30 mm).

Specifications

Detector Type Single Axis Position Sensing Detectors

 Anode Outputs (Common Cathode)

 Cathode Outputs (Common Anode)

 Bi-Cell (Common Anode or Cathode)

Input Sensitivity

-3 -4 -5
10 A/V 10 A/V 10 A/V

Y Output Signal 0V to ± 10V

Sum Output Signal 10V max

Calibration Adjust ± 10% of reading

Y Zero (offset) ± 1.0V

Bias Voltage 0V, ± 5V, or ± 12V

Linearity ± 0.1%

Chanel to chanel tracking 1%

Power AC Adapter ± 12V DC @ 500mA

Size 3.5 x 5.0 inches

Input Connector Receptacle DB9

Output/Power Connector Dual Row 10 PIN Header

Amplifier Gain

6 Position DIP SwitchGain
ON = 1,410-3 A/V
ON = 2,510-4 A/V
ON = 3,610-5 A/V

PSD INPUT CABLE

PIN#FUNCTION
1Y1 PSD Anode
2Y2 PSD Anode
3N/C
4N/C
5GND
6NC
7NC
8PSD BIAS
9GND

POSITION OUTPUT/POWER INPUT

PIN#FUNCTION
1Y pos
2GND
3SUM
4GND
5N/C
6GND
7+12V
8GND
9-12V
10GND