9

SY58013U

Micrel, Inc.

M9999-063010

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

Figure 4. Parallel Termination–Thevenin Equivalent

Note 1. For +2.5V systems: R1 = 250 ohms, R2 = 62.5 ohms

Note 2. For +3.3V systems: R1 = 130 ohms, R2 = 82 ohms

Figure 5. Three-Resistor “Y–Termination”

Note 1. Power-saving alternative to Thevenin termination.

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

possible.

Note 4. C1 is an optional bypass capacitor intended to compensate for

any

OUTPUT TERMINATION RECOMMENDATIONS

LVPECL outputs have very low output impedance (open

emitter), and small signal swing which results in low EMI

(electro-magnetic interference). The LVPECL is ideal for

driving 50 ohms and 100 ohms controlled impedance

transmission lines. In addition, LVPECL is compatible for

driving standard PECL inputs since PECL inputs require only

100mV input swing. Further, there are several techniques

in terminating the LVPECL outputs, as shown in Figure 4

through 6.

Figure 6. Terminating Unused I/O

Note 1. Unused output (/Q) must be terminated to balance the output.

Note 2. For+2.5Vsystems: R1=250ohms,R2=62.5ohms,R3=1.25kohms,

R4 = 1.2k ohms.

For +3.3V systems: R1 = 130 ohms, R2 = 82 ohms, R3 = 1k ohms,

R4 = 1.6k

ohms.

Note 3. Unusedoutputpairs(Qand/Q)maybeleftfloating.

Part Number

Function

Data Sheet link

SY58011U

7GHz, 1:2 CML Fanout Buffer/Translator

http://www.micrel.com/product-info/prod/ucts/sy58011u.shtml

With Internal I/O Termination

SY58012U

5GHz, 1:2 LVPECL Fanout Buffer/Translator With

http://www.micrel.com/product-info/products/sy58012u.shtml

Internal Input Termination

SY58013U

6GHz, 1:2 Fanout Buffer/Translator w/400mV

http://www.micrel.com/product-info/products/sy58013u.shtml

LVPECL Outputs and Internal Input Termination

www.amkor.com/products/notes_papers/mlf_AppNote_0902.

Exposed Pad Application Note

.pdf

M-0317

HBW Solutions

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

RElATED MICREl PRODUCTS AND SUPPORT DOCUMENTATION