7

SY58032U

Micrel, Inc.

M9999-072205

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

Part Number

Function

Data Sheet Link

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

32-MLF™ Manufacturing Guidelines Exposed Pad

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

82

Ω

R2

82

Ω

For +2.5V systems,

R1 = 250

Ω, R2 = 62.5Ω

+3.3V

+3.3V

R1

130

Ω

R1

130

Ω

+3.3V

Figure 4. Parallel Termination-Thevenin Equivalent

LVPECL OUTPUT

LVPECL has high input impedance, and very low output

impedance (open emitter), and small signal swing which

results in low EMI. LVPECL is ideal for driving 50

Ω and

100

Ω controlled impedance transmission lines. There are

several

techniques

for

terminating

the

LVPECL

output: Parallel Termination-Thevenin Equivalent, Parallel

Termination (3-resistor), and AC-coupled Termination.

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

ended outputs must be terminated, or balanced.

Z = 50

Ω

Z = 50

Ω

50

Ω

50

Ω

+3.3V

+3.3V

“source”

“destination”

C1 (optional)

0.01

µF

Notes:

1. Power-saving alternative to Thevenin termination.

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

Figure 5. Parallel Termination (3-Resistor)