Analog Discovery Universal Adapter 2-Set

The genuine BNC adapter is an unbalanced input via a BNC connector.
This Universal Adapter is an original differential input adapter designed with reference to the input switching section of the Tektronix ADA400.

What you will receive is the main unit and a cable with one open end.
The AD2 and cables used for measurement are not included.

Since the W1 signal can be input to CH.1 and CH.2 via a switch, calibration becomes easy.

Both types have the same functionality, only the input connectors differ.
They can be conveniently used separately.
The measured Bode Plot (Images 3 and 4) has a vertical axis of Full Scale +/-5db.
The through characteristic is flat up to 10MHz.

- The input can be switched between AC coupling, GND, and DC coupling using a slide switch.
The 4 inputs of AD's +I1, -I1, +I2, and -I2 can be switched independently.
- When switched to GND, the signal is disconnected from the input terminal and the AD input is connected to GND (also used during calibration).
If you set it to GND before connecting the signal, the AC coupling capacitor will be pre-charged, allowing for safe switching.
- When the NETWORK ANALYZER switch is turned on, W1 is connected to CH.1, reducing the number of connections and making it convenient.
It can also be used for calibration and is convenient.
The -I1 input of CH.1 is connected to the W1 GND.
- When the CALIBRATION switch is turned on during calibration, W1 is connected to CH.2.
- Noise is slightly reduced by a filter using ferrite beads and MLCC for the power output. Confirmed with the AD's own spectrum analyzer.
- The W1 and W2 outputs can be series terminated with 50Ω using a switch.
- In addition to the XH output connectors for W1 and W2, a BNC has been provided for W1 monitoring.
During calibration, this BNC output is connected to a digital voltmeter.
When W2 calibration is not required, calibration can be completed solely by switching the switches on this board.

The red PCB is a pattern reference diagram but is available for purchase.

Reference: Calibration Method
http://analog-discovery.hatenablog.com/entry/universal.adapter