bq77910 charger detect input necessary?

The bq77910 needsthe CHGST pin for a variety of operations described in the data sheet, including wake up from shutdown, programming, fault recovery and some balancing modes.

One reason for not tying CHGST high permanently is that there is no way to recover from a short circuit in charge fault, see table 2 of the data sheet, page 21. While the part has many configuration options, it requires CHGST low for that fault recovery.

System requirements and design will determine whether the part is practical.  Some ideas on reducing the number of pins in an implementation:

• If the system has a temp sense terminal for the battery, use that to control the CHGST
• Connect a charge control signal to PACK+ with a wide contact on the charger
• If there are separate charge and discharge wiring paths, connect charge with a diode and filter components.
• Use a manual reset switch for the rare or unexpected SCC fault recovery.
• Provide a charge control signal on a maintenance connector if appropriate for the equipment environment.
• If the battery system includes a microcontroller, have it provide CHGST when the charger is detected.
• Provide a circuit to recognize the charger presence and create a CHGST signal by monitoring some voltage condition. These are likely to require some specific behavior from the charger.

Perhaps other community members will share methods they have used for this situation.