My design drives this device with -16V for an intended regulated output of -15
Problem: no output (-0.3v or so).
The EN pin is tied to the -16V input.
Then, I read the data sheet:
Absolute Maximum Ratings
EN to GND 5 V to VIN
EN to VIN +30 V to −0.3 V
Pin Configurations and Function Descriptions
EN Drive EN 2 V above or below ground to enable the regulator, or drive EN to ground to turn off the regulator. For automatic startup, connect EN to VIN.
These seem ambiguous. VIN is -16V, well below the -0.3V absolute maximum for the EN pin. The data sheet can't be right.
I hesitate to tie EN to +5V until I hear from the experts.
There may be some misunderstanding here. The absolute max positive voltage on EN pin is 5V and the absolute max negative voltage is VIN-0.3V. And you could use positive ( VEN>1.2V and VEN<5V, as 5V is the max absolute rating) or negative voltage ( VIN<=VEN<-2V) for enable as shown in fig 83, 84,85. Connecting EN to VIN for automatic startup is correct.
Is the exposed pad on the bottom of the IC connected right? Is it connected to VIN? Thanks.
Is the exposed pad on the bottom of the connected right? Is it connected to VIN?
It's connected straight on to GND.
Back to the data sheet!
In the Data Sheet the Exposed pad is told to connected to VIN , but in Fig 101 it is connected to GND .
Which one is correct .
With best regards and wishes
Good catch! The exposed pad should be connected to Vin and Figure 101 in the datasheet will need to be fixed.