Semiconductor Group

6

TCA 505 BG

Pin Functions

Pin 1; LC

The resonant circuit of the proximity switch is connected between LC and ground.

A resistor between this pin and ground sets the current in the oscillator circuit. The greater the

value of the resistor, the smaller is the current feed from the oscillator into the resonant circuit

and the greater therefore is the switching distance. The greater the Q of the resonant circuit,

the greater is the value of the distance resistor necessary for setting a certain switching

distance.

can remain open; if high noise immunity is to be achieved however, this pin should be

element on this pin will also prevent any erroneous pulses on the output when the supply

voltage is turned on (see application circuit 1).

or made high-impedance (see application circuit 1).

Pin 6; SC

SC serves for short-circuit sensing in the output circuit that is to be protected. The current can

output circuit. For a voltage drop

are turned off after the turn-OFF delay (brief glitches on the outputs or the charging of line

capacitances therefore do not trigger the short-circuit protection). After a pause about 200

times the turn-off delay, the outputs turn-ON again. If the short-circuit is still present, the turn-

OFF cycle will start up anew.