3

Exar Coporation 48720 Kato Road, Fremont CA, 94538 • (50) 668-7000 • Fax (50) 668-707 • www.exar.com

SP505_00_08308

Figure 34. Driver Timing Test Load Circuit

Figure 35. Receiver Timing Test Load Circuit

500Ω

Output

Under

Test

1KΩ

1KΩ

R eceiver

Output

Test P oint

Figure 36. Driver Propagation Delays

Figure 37. Driver Enable and Disable Times

+3V

0V

DEC

X

5V

A,B

0V

1.5V

1.5V

t

ZL

t

ZH

f = 1MHz; t

A,B

2.3V

2.3V

t

LZ

t

HZ

0.5V

0.5V

Output normally LOW

Output normally HIGH

TX

ENABLE

Figure 38. Receiver Propagation Delays

+3V

0V

DRIVER

INPUT

B

A

DRIVER

OUTPUT

V

O

+

DIFFERENTIAL

OUTPUT

V

0V

V

O

–

1.5V

1.5V

t

DPLH

t

F

t

R

f ≥ 5MHz; t

V

O

1/2V

O

1/2V

O

t

DPHL

t

t

PHL

t

PLH

R E CE IVE R OUT

OUTP UT

A – B

0V

0V

INP UT