ISL5586

FN4924 Rev 2.00

Page 19 of 20

Nov 3, 2004

Interface Diagram

The figure 15 above shows the electrical interface between

the ISL5586 and the BCM3352. Only a single channel is

shown to simplify the diagram. This diagram only shows

electrical interfaces and pertinent external components

Receive Interface

The receive interface of the BCM3352 is directly coupled to

the ISL5586 differential receive input. External filter

capacitors are provided to minimize noise from the

BCM3352. The ISL5586 is designed with a 4-wire to 2-wire

gain of +2.98dB.

Transmit Interface

The differential transmit output of the ISL5586 is AC coupled

to an external passive network. The external passive

network accomplishes many tasks. First, it filters the noise

which may exist on the CMLEVEL output of the BCM3352.

Second, it biases the ground referenced output signals of

the ISL5586 to the CMLEVEL of the BCM3352. Lastly, the

external network attenuates the signal levels coming from

the ISL5586. The ISL5586 is designed with a 2-wire to 4-

wire gain of 0dB and a 4-wire to 4-wire gain of +2.98dB.

Ringing Interface

The ISL5586 only passes the ringing signal on VRSP, VRSM

to Tip and ring only during the ringing mode. Therefore, a

single ringing generator as supplied by the BCM3352 drives

all four sets of ringing inputs in the Broadcom reference

design. The ISL5586 is designed with a differential ringing

gain of 100V/V.

Passive Component Values

The passive component values in the Broadcom reference

design may not be reflected by this document. Please refer

to the Broadcom reference design documentation for the

most recent schematic and COM information.

TABLE 2. BASIC APPLICATION CIRCUIT COMPONENT LIST

COMPONENT

VALUE

TOLERANCE

RATING

U1 - Ringing SLIC

ISL5586

N/A

N/A

17.8k



1%

0.1W

22.1k



1%

0.1W

40k



1%

0.1W

71.5k



1%

0.1W

66.5k



1%

0.1W

0



1%

0.1W

Not Populated

20%

10V

0.47

F

20%

10V

CFB

1.0

F

20%

10V

4.7

F

20%

10V

0.47

F

20%

>100V

0.1

F

20%

100V

4.7

F

3300pF

150pF

1N400X Type with Breakdown > 100V.

1N4935 Type

Protection resistor values are application dependent and will be determined by protection

requirements. Standard applications will use

49 per side.

Impedance = (3*66.5k

/400 = 498.8, protection resistors = 50, impedance across Tip and Ring terminals = 599. Transient current

limit = 100mA.