With bus bar connected to a VC channel individually, the upper CB pin on that channel is left floating to avoid forward biasing the internal CBFET (see Figure 9-56 (a) connection). This connection applies to bus bar connecting to any middle VC channel individually. That is, in a single device, there is a cell connected above and below the VC channel with bus bar connected. To ensure hotplug performance, the CB channel where the bus bar is connected will still have the differential capacitor even if the upper CB pin is floating. This capacitor forms a complete capacitor ladder from all cells and the bus bar connected to the device, allowing high-voltage spike during hotplug to distribute across the capacitor ladder.

If bus bar is connected to above the top of a module to an individual VC channel (see Figure 9-56 (b) connection), the upper CB pin on that channel is left floating but the CB differential capacitor will still be connected. Additionally, an additional RC filter is connected from the top CB pin to the BAT pin. This additional RC filter (using the same RC values as the other RC filter on the CB pins) is to ensure a complete capacitor ladder is formed for the device to distribute the high voltage spike with the same RC constant as the reset of the CB pins during hotplug event.

Figure 9-56 Bus Bar Connected to Individual VC Channel