Picotest J2110A 40MHz DC semiconductor voltage injector, 12V, 20mA

Product overview

Although it is possible to obtain high-quality injection transformers with bandwidths from 1Hz to 5MHz, in some cases this is still insufficient for particular tests. A typical heater control loop can have a bandwidth of less than 1Hz, but some linear regulators and operational amplifier (op amp) circuits can have a bandwidth of up to 100MHz, and in some cases even more. In such applications, a solid-state injector can provide the required bandwidth. It can operate at DC voltage, and the upper frequency limit depends on the components selected and the board material and layout. It is possible to obtain a solid-state injector with a DC operating range up to 200MHz, although above 50MHz the connection between the injector and the circuit under test can become quite critical. It is important that the ripple from the power supply to the injector does not drastically degrade the dynamic range or signal-to-noise ratio of the measurement. When using a solid-state injector, the graphs are often much cleaner than with a transformer injector.

Choosing the right injection point in a circuit is more critical when using a solid-state injector than a transformer injector. A solid-state injector has infinite impedance between injection points. To get correct results, one side of the measurement must have a much higher impedance than the other side. In a typical power control loop, a good injection point is usually a voltage divider, because the output impedance of the power supply is very low compared to the impedance of the voltage divider.

The solid-state injector has a limited operating voltage, in most cases, of 10 V or 12 V. This is not the amplitude of the injection signal, but the peak value (positive or negative) of the signal's operating voltage.

Key features

• DC-45MHz - this allows thermal and mechanical control and the use of regulators and amplifiers with the highest efficiency
• Low distortion with the highest precision
• Injection resistance: 25 Ohms
• Oscillator input: 50 Ohms
• < 3uA typical bias current
• > 2 MΩ typical input resistance
• High PSRR Low-noise regulator with universal input

Selected parameters