A line injector measure filters and ICs PSRRs

Line Injector

Sold by Stephan Electronics


No tax for United States [change]
the typical connector bundle you'll need
a low frequency DC block to protect your test equipment
Extremely low noise amplifier for >80dB PSRR measurements
Stock available: 50

Product Overview

This line injector is meant to be inserted inline with your positive power supply lines to inject any kind of perturbation signal.
By measuring the perturbation signal before and after your Device Under Test (DUT) you can then deduce how good the DUT is at filtering out unwanted noise at different frequencies.


  • up to 60V / 5A
  • >50MHz injection frequency
  • (optional) connector bundle for standard tests
  • (optional) 7Hz DC blocks with PIN diode protection
  • (optional) low noise amplifier for >80dB PSRR measurements

The connector bundle includes a jack to BNC adapter, a BNC to SMA adapter, 3x SMA T junctions and 10 SMA connectors to assemble to your DUTs if needed.
If used, the 7Hz DC blocks shouldn't be hot plugged as the PIN diode protection will trigger (as the source isn't 50R). Please make your setup then apply power.
Finally, our low noise amplifier will enable 50R noise limited measurements, a must when trying to measure >80dB PSRRs.

Typical use case - LDO PSRR measurement

Line injectors allows you to measure in circuit Power Supply Rejection Ratio, which is often different from the one specified in an LDO datasheet during to parasitic couplings.
Together with a low frequency VNA (or oscilloscope with tracking generator), you'll get typical PSRR curves as the one below:

Typical use case - RC filter

As you may know, ceramic capacitors' capacitance changes with the voltage applied to their terminals. When designing a typical RC filter, this line injector will allow you to characterize your 3dB corner frequencies across bias voltages.

Links to code and documentation

Documentation (limpkin.fr)

Design Files (github.com)

Schematics (github.com)

Bom (github.com)

Product HS Code: 85419000

Shipping policy

All of our devices are shipped from Shenzhen, China. It takes between 2 to 3 weeks to receive your order.

The seller

Stephan Electronics

Lausanne, VD, Switzerland
55 orders since Apr 4, 2022
From the creator of www.limpkin.fr, this shop lets you buy different open hardware projects.