7/24

AN1673 APPLICATION NOTE

ENABLE FUNCTIONS.

The L6598 is provided with two different enable inputs, EN1 (pin8) and EN2 (pin 9), suitable for a flexible

control of the application.

The Enable 1 (active high) threshold is typically 0.6V. When activated, it forces the device in a latched shut

down state in which the oscillator is stopped and both HVG and LVG are cut off, like in the under voltage

condition. In this state the device sinks from the supply a low quiescent current (250

µA max.). There are

two ways to restart the device: one is reducing the supply voltage below the turn off threshold (then turning

it on again). The second is activating Enable 2 input (fig.6). Latched O.V.P function can be achieved using

this function.

Figure 6. Enable 1 timing diagrams

The En2, active high, has a typical threshold of 1.2V. It restarts the start up sequence and, if the En1 has

been previously activated, it resumes from the latched condition (fig.7).

Figure 7. Enable 2 timing diagrams

EN1

EN2

LVG

HVG

D98IN890

VS

EN2

D03IN1443