Normally the clip detector signalling produces a

low level at pin 10 that is shorter than that present

under faulty conditions; based on this assumption

an interface circuitry to differentiate the informa-

tion is represented in the schematic of fig. 26.

Figure 26.

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7

PCB-LAYOUT GROUNDING (general rules)

The device has 2 distinct ground leads, P-GND

(POWER

GROUND)

and

S-GND

(SIGNAL

GROUND) which are practically disconnected

from each other at chip level. Proper operation re-

quires that P-GND and S-GND leads be con-

nected together on the PCB-layout by means of

reasonably low-resistance tracks.

As for the PCB-ground configuration, a star-like

arrangement whose center is represented by the

supply-filtering electrolytic capacitor ground is

highly advisable. In such context, at least 2 sepa-

rate paths have to be provided, one for P-GND

and one for S-GND. The correct ground assign-

ments are as follows:

STANDBY CAPACITOR, pin 7 (or any other

standby driving networks): on S-GND

SVR CAPACITOR (pin 6): on S-GND and to be

placed as close as possible to the device.

INPUT SIGNAL GROUND (from active/passive

signal processor stages): on S-GND.

SUPPLY FILTERING CAPACITORS (pins 3,13):

on P-GND. The (-) terminal of the electrolytic ca-

pacitor has to be directly tied to the battery (-) line

and this should represent the starting point for all

the ground paths.

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