Filter Box

MCE Filter Board

The filter board is sealed in a faraday cage and connects to the cryostat MDM connectors using a drive shaft. Each analog signal from the cryostat is filtered using a 150pF capacitor connected between the signal and the chassis or cryostat wall. The MCE uses 5 identical filter boards that attach directly to the cryostat wall.

Notes

1k PCB capacitance

Typical Readout sig/ret capacitive load = 16pF +/- 2pF

Typical row_select sig/ret capacitive load = 23pF +/- 1pF

(both measured at 100Hz, 1kHz, 10kHz, and 100kHz using a Wayne Kerr Automatic LCR meter (4250)

Cryocable Impedance

Bandwidth restriction caused by cable impedance in conjunction with the filter

Assuming 100pf/200-Ohm cable and 150pf filter, the cable has a pole at: 3.2MHz

Rdyn of SSA

about few hundred ohms: 100 to 600 Ohm