LMZ36002: Table 6.5 INH Threshold vs UVLO Threshold

Hello

I understand your confusion.  The wording in the data sheet can lead to confusion.

The UVLO threshold shown in section 6.5 should be thought of as an "internal UVLO".

The device will turn on and off at those levels without any modification by the user.

However, the feature shown in section 7.3.9 should be labeled an "external UVLO".

This feature is used when the user needs the device to turn on and off at levels higher

than the 3.2V/2.8V mentioned in section 6.5.  As an example, suppose that you wish the 

converter to turn on at an input voltage of 15V; because of some system requirement.

Then you would use the resistor divider shown in section 7.3.9 and either calculate the

values or use table 10.  Since the divider is connected to the INH pin, the thresholds to 

use are the 2.1V values.  When using this feature, the device will internally turn on when the

input voltage reaches 3.2V, but the output will be disabled.  Once the input voltage reaches 15V,

in our example, then the output will start up.  

If you don't need the feature of "external UVLO", shown in section 7.3.9 then you would not

need the divider and just use the INH input as a normal on/off control.  In that case the

device will start-up at about 3.2V input, but would not regulate the output until Vin reached about 

Vout/0.75; as mentioned in section 7.3.9.

Please let me know if the above makes sense.

Thanks