LNBK20D2

2/14

available (EXTM). An appropriate DC blocking

capacitor must be used to couple the modulating

signal source to the EXTM pin. When external

modulation is not used, the relevant pin can be left

open.

Two pins are dedicated to the overcurrent

protection/monitoring:

CEXT

and

OLF.

The

overcurrent protection circuit works dynamically:

as soon as an overload is detected in either LNB

output, the output is shut-down for a time Toff

determined by the capacitor connected between

CEXT and GND. Simultaneously the OLF pin, that

is an open collector diagnostic output flag, from

HIGH IMPEDANCE state goes LOW.

After the time has elapsed, the output is resumed

IMPEDANCE. If the overload is still present, the

value is 1200ms when a 4.7

µF external capacitor

is used.

This dynamic operation can greatly reduce the

power dissipation in short circuit condition, still

ensuring excellent power-on start up even with

highly capacitive loads on LNB outputs.

The device is packaged in Multiwatt15 for

thru-holes mounting and in PowerSO-20 for

surface mounting. When a limited functionality in a

smaller package matches design needs, a range

of cost-effective PowerSO-10 solutions is also

offered.

All

versions

have

built-in

thermal

protection against overheating damage.

(*): External components are needed to comply to level 2.x and above (bidirectiona) DiSEqC

™ bus hardware requirements. DiSEqC™ is a

trademark or EUTELSAT.

PIN CONFIGURATION (top view)