FAQ #15: What injectors should I order?
What injectors should I order?
Most users purchase cost saving “bundles” and we have several to choose from on our website. Please see https://www.picotest.com/products_injb01.html, https://www.picotest.com/products_injb02.html and https://www.picotest.com/products_injb02.html
As a rule, bundle 3 on our website is ideal for measuring DC/DC converters. This bundle includes all of the most generally used injectors. Individual injectors can be selected based on the desired testing. For example:
For low frequency measurement, such as PFC’s, you should use the J2100A transformer which measures as low as 1Hz and up to approximately 5MHz.
For LDO’s the J2101A is a bit higher frequency, starting at 10Hz and having a usable bandwidth up to 40MHz. The J2110A is a much wider bandwidth injector (DC-40MHz+) and will result in lower noise than the transformers
We can also measure phase margin without access to the control loop. This requires the J2111A current injector, which also measures output impedance and small signal step load response (20nSec edge speed up to 40MHz).
If you want to measure PSRR or CS01 or CS02 performance you would need the J2120A.
For all bode measurements, you should have an attenuator, as it is often difficult to get small enough signals to be small signal without it. Our J2140A is a cascadable attenuator, covering 10dB to 70dB in 10dB steps.