Detailed description

STOD14

14/22

Doc ID 023562 Rev 1

under regulation about 10 ms after the Enable pin is asserted high. The short-circuit

protection is designed to prevent overload, performing a dynamic current limitation on both

output pins. At light load condition (up to 150 mA), the load can be connected during the

startup phase. At medium/high load condition (above 150 mA), the proper sequence needs

the startup phase to be entirely completed before connecting a load.

7.5

Fast discharge

When the device goes into shutdown mode and LX1 and LX2 stop switching, the discharge

the positive and the negative output voltages. After output voltages are discharged to zero,

the switches turn off and the outputs stay in high impedance state.

7.6

Undervoltage lockout

The undervoltage lockout function avoids improper operation of the device when the input

voltage is not high enough. When the input voltage is below the UVLO threshold, the device

is in shutdown mode. The hysteresis avoids unstable operation at input voltage levels close

to the UVLO threshold.

7.7

Overtemperature protection

An internal temperature sensor continuously monitors the IC junction temperature. If the

temperature exceeds the specified value (see Table 5) the device stops operating. As soon

as the temperature falls below the threshold (including hysteresis), normal operation is

restored.

7.8

Short-circuit startup detection (SSD)

During device soft-start on positive output, an internal comparator checks load condition to

detect eventual panel damage. In such case soft-start is stopped and the device is parked in

power-off. To reset the normal functionality (assuming that the anomalous load condition

was removed), it is necessary to restart the converter by an enable transient.

If no damage is detected during soft-start on the positive output, the startup procedure

follows with negative output soft-start to reach, at the end, normal outputs functionality and

voltages.

7.9

Overload protection (OLP)

Output current is internally limited. An overload condition, as a short-circuit between the two

outputs or between each output and GND, produces the device power-off. To reset normal

functionality (assuming that the short condition was removed), it is necessary to restart the

converter by an enable transient.

7.10

Short-circuit protection (SCP)