Functional description

L9826

16/19

Doc ID 7214 Rev 10

5.4

Protections

5.4.1

Flyback current

Turning off the low side driver with an inductive load, its output voltage rises due to the

inductor that tries to drive current. This voltage is internally clamped by the flyback circuit at

VCPL value, typical 50V

5.4.2

Current regulation mode outputs 1 and 2

Outputs 1 and 2 which are particularly dedicated for loads with inrush current (as lamps).

When the channel is switched on and the current through the load exceeds the short circuit

limit value (Ilim) for at least tdf time, the corresponding output goes in current regulation

mode.

The output current is determinated by the output characteristic and its voltage depends on

load resistance. In this mode, high power is dissipated in the output stage and its

temperature increases rapidly. When the output stage temperature exceeds the thermal

shutdown (TJSC), the overload latch is set and the corresponding output is switched off.

5.4.3

Short circuits outputs 3 to 8

Outputs 3 to 8 which are dedicated for loads without inrush currents. When the output

current exceeds the short circuit threshold (Isbc) for at least Tscb time, the corresponding

output is switched-off immediately and in the same time, the relative latch store the overload

status.