# Line Injector

A line injector measure filters and ICs PSRRs

- **Seller:** [Stephan Electronics](https://lectronz.com/stores/stephanelec), Lausanne, VD, Switzerland
- **Price:** €53.00 (EUR, before shipping and taxes)
- **Availability:** In stock
- **Categories:** Sensors
- **HS code:** 85419000
- **Product page:** https://lectronz.com/products/line-injector

## Options

**Connector bundle**

- without connector bundle (49 left)
- with connector bundle [Add €17.00] (48 left)

**Low frequency DC block**

- without DC block (50 left)
- with 2x DC block [Add €45.00] (47 left)

**Low noise amplifier**

- without amplifier (48 left)
- with amplifier [Add €230.00] (49 left)

## Links

- [Documentation](https://www.limpkin.fr/index.php?post/2024/03/24/A-Small-Line-Injector-to-Measure-PSRR)
- [Design Files](https://github.com/limpkin/line_injector)
- [Schematics](https://github.com/limpkin/line_injector)
- [Bom](https://github.com/limpkin/line_injector)

## Images

![Line Injector](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTMwNjEsInB1ciI6ImJsb2JfaWQifX0=--28d67b49eb44c1218bde86ff5dd25c822873c45b/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJKUEciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--a1419a086f227676aca33a49760ac51e58b523e3/line_injector_small.JPG)
![Line Injector](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTMwNjUsInB1ciI6ImJsb2JfaWQifX0=--2df0ca706d9544653430cac028006ca31d46e6bf/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJKUEciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--a1419a086f227676aca33a49760ac51e58b523e3/back_small.JPG)
![Line Injector](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTMwNjksInB1ciI6ImJsb2JfaWQifX0=--7de409167f9909c54587fc31ce013162cb32ef2b/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJKUEciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--a1419a086f227676aca33a49760ac51e58b523e3/injector%20with%20con%20bundle%20small.JPG)
![Line Injector](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTMwNzMsInB1ciI6ImJsb2JfaWQifX0=--bd7ed36a5763ed52e6593a58106d438e952fe8b8/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJKUEciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--a1419a086f227676aca33a49760ac51e58b523e3/injector%20with%20bundle%20dc%20block%20small.JPG)
![Line Injector](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTMwNzcsInB1ciI6ImJsb2JfaWQifX0=--76527e63928ffa0b74782578912d40b205f228cb/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJKUEciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--a1419a086f227676aca33a49760ac51e58b523e3/injector%20with%20bundle%20dc%20block%20amplifier%20small.JPG)

## Description

## Product Overview
![](https://www.limpkin.fr/public/line_injector/.line_injector_principle_m.png "")  
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.  
![](http://www.limpkin.fr/public/mooltipass_mini/10px.png "")

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## Specifications
- 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](https://www.tindie.com/products/stephanelec/7hz-50v-dc-block/) **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](https://www.tindie.com/products/stephanelec/extremely-low-noise-dc-to-600khz-34db-amplifier/) will enable 50R noise limited measurements, a must when trying to measure >80dB PSRRs.  
![](http://www.limpkin.fr/public/mooltipass_mini/10px.png "")

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## Typical use case - LDO PSRR measurement
![](https://www.limpkin.fr/public/line_injector/.ams1117_test_setup_m.jpg "")  
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:  
![](http://www.limpkin.fr/public/mooltipass_mini/10px.png "")  
![](https://www.limpkin.fr/public/line_injector/.AMS1117-3.3_PSRR_m.png "")
![](http://www.limpkin.fr/public/mooltipass_mini/10px.png "")

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## Typical use case - RC filter
![](https://www.limpkin.fr/public/line_injector/.rc_circuit_m.png "")  
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.

## Shipping policy

All of our devices are shipped from Shenzhen, China. It takes between 2 to 3 weeks to receive your order.
Swiss customers: please contact us directly to arrange a local sale.