Product Overview

This device allows you to amplify by 34dB (50x when connected to a 50R device or 100x when connected to a high impedance device such as an oscilloscope) signals whose frequencies are anywhere between 0Hz (DC) and 600kHz.

Intended Use

This amplifier's purpose is to amplify extremely low amplitude signals whose frequencies are below 1MHz.
Typical measurements include:
- audio equipment noise floor
- phase locked loop error signals
- power supplies switching noise (using a DC block)
- switching noise coupling on high impedance traces

Extremely Low Noise

The amplifier input stage uses the LT1028 that has a typical input referred voltage noise of 0.9nV/sq(Hz). For actual measurements of its noise characteristics, have a look at the above output noise measured spectrum, keeping in mind that the gain is 34dB.

Output Clipper

The amplifier is DC coupled, effectively meaning that any input DC component gets amplified.
Spectrum Analyzers typically come with a no DC at the input requirement, which typically means a 200mV maximum input DC component. This amplifier therefore includes a configurable output clipper that will allow you to protect your spectrum analyzer input stage (for more details, please read here).

Battery Powered with an Aluminum Case

To prevent grounds loops and external power supply noise coupling the amplifier uses 2 9V batteries, which when using Energizer Ultimate Lithium batteries means a battery life of 47 hours but will heavily depend on use.
The case is made of a single machined aluminum block, which will also prevent environmental noise from being picked up.

Main Specifications

• 0mV output offset voltage
• 22dBm maximum output level
• typical 0.9nV/sq(Hz) noise floor
• 34dB gain between DC and 375kHz (.1dB)
• 34dB gain between DC and 600kHz (3dB)
• clipper activation artifact: 800ns 4V pulse (see here)

Additional High Pass Filter

As the amplifier input is DC-coupled, a high pass filter (or DC-block) is needed when wanting to measure AC frequencies located on top of DC signals (for example: switching ripple on voltage rails). You may therefore add to your order a DC-block with a 7Hz corner frequency.