8

SY58033U

Micrel, Inc.

M9999-072810

hbwhelp@micrel.com or (408) 955-1690

PartNumber Function

DataSheetLink

SY58031U

Ultra-Precision 1:8 Fanout Buffer with 400mV CML

http://www.micrel.com/product-info/products/sy58031u.shtml

Outputs and Internal I/O Termination

SY58032U

Ultra-Precision 1:8 Fanout Buffer with LVPECL

http://www.micrel.com/product-info/products/sy58032u.shtml

Outputs and Internal Termination

SY58033U

Ultra-Precision 1:8 Fanout Buffer with 400mV LVPECL

http://www.micrel.com/product-info/products/sy58033u.shtml

Outputs and Internal Termination

www.amkor.com/products/notes_papers/MLF_AppNote_0902.pdf

Application Note

HBW Solutions

http://www.micrel.com/product-info/as/solutions.shtml

RELATED MICREL PRODUCTS AND SUPPORT DOCUMENTATION

R2

82Ω

R2

82Ω

For +2.5V systems,

R1 = 250Ω, R2 = 62.5Ω

+3.3V

+3.3V

R1

130Ω

R1

130Ω

+3.3V

Figure4.ParallelTermination-TheveninEquivalent

LVPECL OUTPUT

Z = 50Ω

Z = 50Ω

50Ω

50Ω

V

3

.

3

+

V

3

.

3

+

n

o

it

a

n

it

s

e

d

e

c

r

u

o

s

C1 (optional)

0.01µF

Notes:

1. Power saving alternative to Thevenin termination.

2. Place termination resistors as close to destination inputs as possible.

Figure5.ParallelTermination(3-Resistor)

LVPECL has high input impedance, and very low output

impedance (open emitter), and small signal swing which

results in low electromagnetic interference (EMI). LVPECL

is ideal for driving 50Ω and 100Ω controlled impedance

transmission lines. There are several techniques in

terminating the LVPECL output, which are the Parallel

Termination-Thevenin Equivalent, the Parallel Termination

(3-Resistor), and the AC-Coupled Termination. Unused

output pairs may be left floating. However, single-ended

outputs must be terminated, or balanced.