A2547

Providing interface between low-level logic and power loads, the UDK/UDN/UDQ2547B and UDK/UDN/UDQ2547EB quad power drivers combine logic gates and high-current bipolar outputs with complete output protection.  Each of the four outputs will sink 600 mA in the ON state.  The outputs of UDK/UDN/UDQ2547B and UDK/UDN/UDQ2547EB have a minimum breakdown voltage (load dump) of 60 V and a sustaining voltage of 40 V.  The inputs of UDK/UDN/UDQ2547B and UDK/UDN/UDQ2547EB are compatible with TTL and 5 V CMOS logic systems and include internal pull-down resistors to ensure that the outputs remain OFF if the inputs
are open-circuited.

Over-current protection of UDK/UDN/UDQ2547B and UDK/UDN/UDQ2547EB for each channel has been designed into these devices and is activated at approximately 1.3 A.  It protects eachout put from short circuits with supply voltages up to 25 V.  When a maximum driver output current is reached, that output of UDK/UDN/UDQ2547B and UDK/UDN/UDQ2547EB drive is reduced linearly, maintaining a constant load current.  If the over-current or short circuit condition continues, each channel has an independent thermal limit circuit which will sense the rise in junction temperature and turn OFF the individual channel that is at fault.  Foldback circuitry decreases the output current if excessive voltage is present across the output and assists in keeping the UDK/UDN/UDQ2547B and UDK/UDN/UDQ2547EB within its SOA (safe operating area).