Octal E1 Line Interface — LXT381

Datasheet

17

Figure 5. External Transmit/Receive Line Circuitry

0.1

µF

3.3V

R

T

R

T

1:2

TTIP

TRING

RTIP

RRING

R

R

R

R

0.22

µF

1:1

2

Typical value. Adjust for actual board parasitics to obtain optimum return loss.

68

µF

1

1

Common decoupling capacitor for all TVCC and TGND pins.

TVCC

D1

D2

TVCC

D3

D4

560pF

2

1k

Ω

1k

Ω

Rx LINE

Tx LINE

VCC

GND

LXT381

(ONE CHANNEL)

0.1

µF

3.3V

3.3V

TVS1

3

3

3

Transformer turns ratio tolerance is ± 2%. See Test Specifications Section for transformer specifications.

COMPONENT

APPLICATION

75

Ω COAX

120

Ω TWISTED PAIR

R

T

R

R

11

Ω ±1%

11

Ω ±1%

37.5

Ω ±1%

60

Ω ±1%

D1 - D4

INTERNATIONAL RECTIFIER

11DQ04 or 10BQ060

MOTOROLA

MBR0540T1

TVS1

SGS-THOMSON

SMLVT 3V3 3.3V