Model 430 lock-in amplifier

Single phase OEM analogue lock-in amplifier

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A single phase lock-in amplifier with manual setting, using jumpers, of input mode, sensitivity, low pass filter time constant and reference signal course phase control.

  • Differential or single-ended input
  • Sensitivities from 3 µV to 10 V for 1 V output
  • High performance wide bandwidth input gain stage
  • Low pass filter output time constants from 100 µs to 30 s
  • 1F and 2F reference signal operation
  • 90° step and fine phase control
  • Power: -15 V, 0 V, +15 V and +5 V dc, at 50 mA per supply rail.

Input Signal Channels

The input signal channel amplifies the input signal to a level suitable for the demodulator. High performance, low-noise, broad-band amplifiers are used throughout. The input circuits can accept differential or single-ended inputs via the input SMB connectors. Options within the unit allow the outer SMB contact or screen to act as a high impedance differential input or allow it to be connected to ground for single-ended operation.

  • Input: Differential or single ended voltage via SMB socket
  • Input Gain: x0.1 to x330 in 1, 3.3, 10 steps
  • Input Impedance: 10¹² // 1 nF, dc coupled
  • Frequency: 10 Hz to 100 kHz
  • Maximum Inputs: ±10 V before saturation occurs
  • Input Noise Voltage: Other lock-in amplifier manufacturers give input noise values but without providing any definition of this specification. Indeed there is no meaningful definition of this specification in relation to lock-in amplifiers. As such, Scitec Instruments does not provide noise values and other manufacturers data sheets are considered misleading. Further details about input noise are available on request
  • Gain Accuracy: 1%
  • Gain Stability: 200ppm/°C
  • Dynamic Reserve: 0dB to 80dB


  • The input stage drives high bandwidth demodulators to recover the input signal.


  • The demodulator outputs are passed through low pass filters before being amplified for output.
  • Output Gain: x1, x10, x100, x1000
  • Low Pass Filter Time Constants: 100 µs to 30 s in 1, 3, 10 steps
  • Outputs – SMB connectors: +/-100 mV to +/-10 V full scale

Reference Channel

A single reference channel is used to generate the signals that drive the demodulator(s). A fine phase shifting circuit allows the reference signal to be phase shifted from 0° to 150° relative to the signal input. A second circuit then produces signals that are phase shifted by 0°, 90°, 180° and 270° at both the reference frequency and twice the reference frequency.

  • Frequency: 10 Hz to 100 kHz Trigger: Standard TTL, mark to space ratio in the range 20:1 to 1:20. Rising edge triggered
  • Acquisition Time: 10 s max.
  • Phase Control: 90° steps + fine shift of 0° – 150°
  • Phase Drift: 0.1°/C
  • 1F and 2F operation


  • Power connections are made via a 64 pin type C DIN41612 connector. Signal connections are not possible via this connector. Mechanical: 100 x 160 mm
  • Temperature Range: 0 – 50°C
  • Warranty: 1 year from date of shipment
  • Phase Drift: 0.1°/C
  • 1F and 2F operation