ATTL7557AAU Ver la hoja de datos (PDF) - Agere -> LSI Corporation

Número de pieza

componentes Descripción

Fabricante

ATTL7557AAU

Low-Power SLICs with Battery Switch

Agere -> LSI Corporation 

L7556, L7557 Low-Power SLICs

with Battery Switch

Data Sheet

January 2000

Applications (continued)

Table 10. Parts List for Loop Start and Ground Start Applications (continued)

Name

Supervision

RLCTH

RTS1

RTS2

CRTS1

CRTS2

RTSN

RTSP

Ground Start

CICM

RGDET

RICM2

Value

24.9 kΩ, 1%, 1/16 W

402 Ω, 5%, 2 W

274 kΩ, 1%, 1/16 W

0.022 µF, 20%, 5 V

0.27 µF, 20%, 100 V

2 MΩ, 1%, 1/16 W

2 MΩ, 1%, 1/16 W

0.47 µF, 20%, 10 V

100 kΩ, 20%, 1/16 W

82.5 kΩ, 1%, 1/16 W

Function

Sets loop closure (off-hook) threshold.

Ringing source series resistor.

With CRTS2, forms first pole of a double pole,

2 Hz ring trip sense filter.

With RTSN, RTSP, forms second 2 Hz filter pole.

With RTS2, forms first 2 Hz filter pole.

With CRTS1, RTSP, forms second 2 Hz filter pole.

With CRTS1, RTSN, forms second 2 Hz filter pole.

Provides 60 Hz filtering for ring ground detection.

Digital output pull-up resistor.

Sets ring ground detection threshold.

Design Considerations

Table 11 shows the design parameters of the application circuit shown in Figure 11. Components that are adjusted

to program these values are also shown.

Table 11. 600 Ω Design Parameters

Design Parameter

Loop Closure Threshold

dc Loop Current Limit

dc Feed Resistance

2-wire Signal Overload Level

ac Termination Impedance

Hybrid Balance Line Impedance

Transmit Gain

Receive Gain

Parameter Value

10 mA

40 mA

180 Ω

3.14 dBm

600 Ω

600 Ω

0 dB

0 dB

Components Adjusted

RLCTH

RPROG

RPT, RPR

—

RT1, RGP, RRCV

RHB1

RT2, RX

RRCV, RGP, RT1

16

Lucent Technologies Inc.

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