U74GTL2014

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

8 of 9

www.unisonic.com.tw

QW-R502-D278.A



TYPICAL APPLICATION (Cont.)

2.

LVTTL/TTL to GTL– /GTL / GTL+:

Because GTL is an open-drain interface, the selection of pullup resistor depends on the application

requirement (for example, data rate) and PCB trace capacitance.

Application Diagram for LVTTL to GTL

2.1

Detailed Design Procedure

To begin the design process, determine the following:

1. Select direction based upon application (GTL– / GTL / GTL+ to LVTTL or LVTTL to GTL– / GTL / GTL+).

2. Set up appropriate DIR pin and VREF / VTT.

3. Choose correct pullup resistor value base upon data rate and driving current requirement

(for LVTTL to GTL– / GTL / GTL+).

2.2

Application Curve