SN65HVD72: About power consumption, want to increase pull high resistance, is it ok?

Hi Bryan,

The SN65HVD72 actually has internal fail-safe biasing so these external biasing resistors only provide extra stability for the system. If the customer is willing to trade this extra bus stability for lower power consumption, the internals of the device should accomplish the same task.

Let me know if you have any more questions.

Regards,
Eric

Hi Bryan,

To elaborate, fail-safe biasing is a way to give a pin a "default" value when disconnected from other sources. This ensures that when the bus is idle, open, or shorted, or a pin is left floating, the device still behaves in a predictable manner. Because of this, if these pullup resisters are increased dramatically or removed and the device pins are disconnected (or connected to high impedance lines), the device pins will follow the behavior given on Table 1 and Table 2 on the datasheet.

Regarding the increase/removal of the bus pullup resistors (R130 and R137), the device treats the inputs (A and B) as high impedance when the driver is disabled, so if other devices on the same bus are relying on the bus being biased while idling, these resistors should be included.

Regards,

Eric