Detailed description

STOD13AS

18/25

Doc ID 022733 Rev 1

8.1.5

Enable pin

The device operates when the EN pin is set high. If the EN pin is set low, the device stops

switching, and all the internal blocks are turned off. In this condition the current drawn from

are in an OFF state so the load is electrically disconnected from the input, this avoids

unwanted current leakage from the input to the load.

8.1.6

Soft-start and inrush current limiting

device initiates the start-up phase.

limiting technique in order to keep the charge current below 400 mA. This avoids the battery

overloading during startup.

procedure for the step-up is started. After around 2 ms the soft-start for the inverting is

started. The positive and negative voltages are under regulation at around 13 ms after the

EN pin is asserted high.

8.1.7

Undervoltage lockout

The undervoltage lockout function avoids improper operation of the STOD13AS 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 of 50 mV avoids unstable operation when the

input voltage is close to the UVLO threshold.

8.1.8

Overtemperature protection

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

temperature exceeds 140 °C, typical, the device stops operating. As soon as the

temperature falls below 125 °C, typical, normal operation is restored.

8.1.9

Short-circuit protection during soft-start (SSD)

During device soft-start on the positive output, an internal comparator checks if the panel is

damaged. In this case, soft-start is stopped and the device is parked in power-off. To reset

the normal functionality (assuming that the anomalous load condition is removed), it is

necessary to restart the converter through an enable transient.

If the panel is not damaged it is possible to proceed with the soft-start of the negative output

and both reach their final value, therefore ensuring normal output voltages and functionality.

8.1.10

Overload protection (OLP)

The 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 the