bq20z75 will not go into Sleep mode

Patrick Mendiuk

I have a bq20z75 that will not enter sleep mode. The SMBus lines are tied to ground with 1M resistors, the SMBus master clock and data lines are set low, and there is less than 10mA current flow (650uA). The SLEEP bit is set in Operation Cfg A and NR is set in Operation Cfg B. There are no PF or Safety Status flags set.

over 14 years ago

0 Patrick Mendiuk over 14 years ago

Intellectual 535 points

Any response?

0 Jackie Hui over 14 years ago in reply to Patrick Mendiuk

TI__Expert 3865 points

What is the sleep current set to and what is the actual current report by the device?

When you said the SMBus lines are set to low, do you mean they are still plug in to the system? Or are they floating and are using the 1M pull down to pull the lines low?

You may want to put a scope on the SMBus lines to double check the condition.

0 Patrick Mendiuk over 14 years ago in reply to Jackie Hui

Intellectual 535 points

The device is permanently connected to the host controller. The SMBus lines are not floating at all. As I mentioned there are 1M pull downs and the host controller IO lines are set to outputs and set low to attempt to put the bq20z75 to sleep. The scope shows the SMBus lines are low (<10mV) and very quiet. The device is reporting -2mA prior to attempting to put it into sleep mode.

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bq20z75 will not go into Sleep mode