Frequency Response Analyser
The Frequency Response Analyser (FRA) control panel lets you stimulate and measure the frequency response of two port networks such as power supplies, filters, audio power amplifiers, power planes, transformers, servo amplifiers and physical systems. You can use it to measure the impedance, phase, capacitance, inductance, Resr and Quality Factor/Dissipation factor of components or networks. We also include power supply specific functions to measure live power supply performance. You can measure the Gain/Phase (with automatic sig gen amplitude control), Input Impedance, Output Impedance, and PSRR vs frequency.
Take the Impedance Measurement Tour to get an introduction to using the FRA system.
The CS701 isolated signal generator is especially useful for stimulating live non-ground referenced feedback loops. It has low capacitance to chassis ground(16pF) , and generates from DC to 65 MHz. You can increase versatility by using the CS1070 power amplifier. It has 50 MHz bandwidth, 1 A output, -20V to +30V output swing and can be used for PSRR, Input and Output impedance measurement, as well as offsetting capacitor DC bias up to 30V.
If you are designing or verifying feedback systems such as power supplies, audio power amplifiers, servo amplifiers and physical positioning systems it is very helpful to measure the Gain/Phase response of the feedback loop. You can use the Phase Margin as a measure of stability. Values of 50-60 degrees represent the optimal response to a step change in load or signal, without oscillation or sluggishness. The FRA uses the CS701 isolated Sine Wave Generator to stimulate the feedback loop at the output of the power supply or amplifier - just where a load would be applied. You don't need an injection transformer as more traditional approaches use, which means you get operation from DC to 65 MHz, no distortion from the transformer, and lower cost. Using a CS328A-FRA you can plot and visualize stability and transient response on a live system. Note that the FRA capability is built into all our capture products. You will however get best performance when using the isolated CS701 signal generator.
The 300 V RMS isolated CS701 can be used on mains powered systems safely, while the +/- 24V DC offset capability of the input to the CS328A-FRA means you can measure the response down to DC in power supplies of up to +/-24V. For higher voltage power supplies, use AC coupling.
The FRA Control Panel makes is easy to set up everything in one place - you don't need to know how to use the rest of the Cleverscope system. Using the FRA control panel you can fully evaluate a transformers transfer response, the primary and secondary inductances, the leakage inductance and interwinding capacitance versus frequency. Using DC offset you can check saturation and DC sensitivity. You don't need to buy an expensive Network Analyser because the Cleverscope FRA does all this for you over a 0-65Mhz frequency range!
Why not check out our Cleverscope FRA white paper on Power supply response. Also check out these videos: