SCT-420 Lock-In Amplifier

Description

SCT-430 and SCT-441 are OEM analogue lock-in amplifiers. Both the single phase SCT-430 and dual phase SCT-441 are suitable for making amplitude and phase measurements but it is significantly easier with SCT-441. These pcb lock-in amplifiers offer  a low cost solution to recovering noisy signals in many situations.

• Single and dual phase versions
• Differentialor single-ended input
• Sensitivities from 1 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

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.

• Sensitivity: 3 µV to 10 V in 1, 3, 10 steps for 1 V output (Gain settings of x 0.1 to x 330000)
• Reference input: TTL / CMOS with mark / space of 1 : 10 to 10 : 1 (triggered from rising edge only)
• Power: -15 V, 0 V, +15 V and +5 V dc at 50 mA per supply rail

Specifications

Input Signal Channels

The input signal channel amplifies the input signal to a level suitable fort he demodulator(s). 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 allo the outer SMB contact or screen to act as a high impedance differential input or allow it tob e connected to ground for single-ended operation

• Input: Differential or single ended voltage via SMB socket
• Input gain: x 0,1 to x 330 in 1, 3.3, 10 steps
• Input Impedance: 12₁₂ // 1 nF, dc coupled
• Frequency: 10 Hz to 100 kHz
• Maximum Inputs: ± 10 V before saturation occurs
• Gain Accuracy: 1 %
• Gain Stability: 200 ppm / °C
• Dynamic Reserve: 0 db to 80 db

Demodulator

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

Output

The demodulator outputs are passed through low pass filters before bein amplified for output.

• Output Gain: x 1, x 10, x 100, x 1000
• 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 tot he 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 0° - 150°
• Phase Drift: 0.1 °/C
• 1F and 2F operation

General

• General 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: 2 years from date of shipment