The Picotest J2100A is a passive injection transformer for loop-gain and stability measurements of switching and linear regulators using a vector or frequency response analyser. Its 1 Hz–5 MHz usable range covers very low-bandwidth power factor correctors (PFC) through to typical power supplies and regulators. Low distortion and a 5 Ω termination minimise loop loading, while built-in attenuation helps ensure small-signal injection for accurate Bode plots.
For higher-frequency loops, see the Picotest J2101A (10 Hz–45 MHz). If you need DC injection or bandwidth beyond the transformer range, consider the solid-state Picotest J2110A. The J2100A works seamlessly with popular analysers such as the OMICRON-Lab Bode 100.
Engineers choose the J2100A when they need reliable, repeatable loop measurements down to 1 Hz with minimal circuit perturbation. Its isolation allows the transformer to float on high-voltage rails during testing, and its termination and attenuation are optimised for common 50 Ω source instruments, simplifying setup and improving measurement consistency.
- condition: new - custom_product: false - mpn: J2100A - google_product_category: Electronics - warranty: 12 months - brand: Picotest - target_keyword: Picotest J2100A - manufacturer: PicoTest Corp - breadcrumbs: ["gid://shopify/Collection/267180835005"] - brands: gid://shopify/Metaobject/56256102623 - customhs_code: 903090 - detailed_description: {"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"The injection transformer is presently the prevalent method for connecting the network analyzer to the circuit being tested, and is primarily used for control loop stability measurements. The goal of the transformer is to inject a signal into the control loop being measured, without impacting the performance of the loop. In order to accomplish this to a reasonable degree, The transformer is isolated and therefore is capable of floating on a high voltage, such as a Power Factor Corrector (PFC), which is often close to 400VDC. Measuring voltages that exceed the voltage rating of the FRA inputs require attenuation probes."}]},{"type":"paragraph","children":[{"type":"text","value":"The usable bandwidth of an injection transformer is generally significantly greater than the 3dB frequency limits. This is because the transformer itself is outside of the measurement, leading many to incorrectly believe that the transformer is a non-critical element."}]},{"type":"paragraph","children":[{"type":"text","value":"The bandwidth of the transformer is strongly related to the terminating impedance. The most network analyzers provide a 50 Ohm oscillator source impedance. Assuming this impedance the optimal termination resistor is 5 Ohms. This significantly attenuates the injection signal, which is generally beneficial, as a common error in Bode measurements is using a signal which is too large, and therefore not a small signal measurement. An added benefit of this low value is that it can generally be left in circuit at all times, simplifying the connection to the network analyzer without appreciably impacting the output voltage of the circuit being tested."}]},{"type":"paragraph","children":[{"type":"text","value":""}]},{"type":"paragraph","children":[{"type":"text","value":" "}]}]} - summary:Discover a new level of measurement accuracy and flexibility with the revolutionary J2100A Injection Transformer. Engineered to enhance your measurement capabilities, this transformer is your ultimate solution for a wide range of applications.
Experience the power of frequencies ranging from 1Hz to 5MHz. From PFC regulators to power supplies, this transformer is designed to handle it all.
With support for 1Hz frequencies, the J2100A is optimized for PFC regulators, ensuring precise measurements and reliable results.
Take advantage of the transformer's upper limit of 5MHz, guaranteeing exceptional precision for demanding power supply and regulator tasks.
Covering an impressive 23 octave range, the J2100A empowers you to tackle diverse measurement scenarios with confidence.
Experience minimal distortion and superior precision, setting a new standard for measurement reliability.
Featuring a 5 Ohm termination, the transformer ensures minimal disruption to the measurement loop, preserving data integrity at all times.
Rest easy knowing that small signal measurements are guaranteed with the included attenuation feature, delivering accurate results every time.
Take your measurements to the next level with the J2100A Injection Transformer. Whether you're a seasoned professional or a newcomer to precision measurement, this transformer is your gateway to unmatched accuracy and reliability. Don't miss out—secure yours today and experience the future of precise measurements!
- key_feature_1: Passive loop-injection transformer for VNA/FRA stability measurements from PFC to point-of-load regulators. - key_feature_2: 1 Hz Low-End Coverage - key_feature_2_tooltip: {"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Measure very low-bandwidth control loops, including PFC stages, without resorting to special fixtures or workarounds, ensuring the injected stimulus is inside the loop’s operating range for valid gain/phase data."}]}]} - key_feature_3: Usable To 5 MHz - key_feature_3_tooltip: {"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Covers the vast majority of SMPS and linear regulators so one transformer handles typical power integrity loop measurements without swapping fixtures or changing topology mid-project."}]}]} - key_feature_4: Low Distortion Injection - key_feature_4_tooltip: {"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Reduces measurement artefacts that can mask true loop behaviour, helping your analyser resolve small-signal responses and phase accurately across frequency."}]}]} - key_feature_5: 5 Ω Termination - key_feature_5_tooltip: {"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Matches common 50 Ω source instruments for minimal loop loading; attenuation ensures “small-signal” conditions so Bode plots reflect true closed-loop dynamics."}]}]} - key_feature_6: Built-In Attenuation - key_feature_6_tooltip: {"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Helps keep injection levels appropriately small, avoiding loop perturbation or non-linear behaviour that can corrupt gain and phase results."}]}]} - key_feature_7: Floating Isolation - key_feature_7_tooltip: {"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Allows the transformer to sit at high DC potentials during tests, supporting offline PSUs and other high-voltage nodes when used within specified insulation category."}]}]} - key_feature_8_tooltip: {"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Combine with J2101A (higher frequency) or J2110A (DC injection) to cover more applications using consistent connections and methods across projects."}]}]} - key_feature_8: Part of A Proven Series - why_people_choose_3_title: Fits Existing Setups - why_people_choose_2_title: Minimal Loop Perturbation - why_people_choose_1_title: Reliable Low-Frequency Coverage - why_people_choose_1: Reaches 1 Hz for PFC control loops while maintaining small-signal integrity for accurate stability analysis. - why_people_choose_3: Works with common FRA/VNAs such as Bode 100, minimising new fixtures and training time. - why_people_choose_2: 5 Ω termination and attenuation reduce loading, improving repeatability across benches and instruments. - 1567922: What measurements is the J2100A designed for?***SIMP***Loop gain, phase margin and crossover analysis using a VNA/FRA with transformer-injection. Works well with the OMICRON-Lab Bode 100 - 1567923: How do I choose between J2100A, J2101A and J2110A?***SIMP***Use J2100A for 1 Hz–5 MHz, J2101A for 10 Hz–45 MHz, and the J2110A when you need DC injection or wider bandwidth. - 1567924: Why is the 5 Ω termination important?***SIMP***It matches a 50 Ω source to minimise loop loading and, with attenuation, helps maintain small-signal injection for accurate Bode plots. - 1567928: Does transformer bandwidth affect accuracy of the Bode plot?***SIMP***Reduced transformer bandwidth mainly reduces injected signal level; with adequate SNR the accuracy of the Bode plot is preserved. - 1567930: Can J2100A be used on high-voltage rails?***SIMP***Yes, within its insulation category and limits so it can float during tests on offline supplies when used correctly with your analyser. - 1567931: Is it compatible with oscilloscopes offering FRA options?***SIMP***Yes. Many scopes with FRA/control-loop options support transformer injection; J2100A also pairs well with dedicated VNAs like the Bode 100 VNA. - 1567932: When should I consider the J2110A solid-state injector?***SIMP***When DC injection is required, or when bandwidth beyond transformer limits is needed. See the J2110A. - 1567933: Is there a higher-frequency transformer in the same series?***SIMP***Yes. The J2101A extends usable frequency up to 45 MHz. - 1567934: What’s the practical advantage of built-in attenuation?***SIMP***It helps ensure small-signal conditions, reducing non-linear effects that can distort gain/phase results.