Application Notes:
Suggested Driver Cir cuit
TGL6425-SCC
OVERVIEW
DRIVER CIRCUIT
SCHEMATIC
The following is a suggested driver circuit for the TriQuint TGL6425-SSC 0.5 to 18 - Ghz
step attenuator. The circuit allows the user to use a digital binary input to achieve the desir ed level
of attenuation; with a digital wor d of “00000” equaling0 -dB relative attenuation and “11111”
equaling 15.5- dB relative attenuation. The JFET s (2N5116 or equivalent) provide the r equired level
shift from TTL voltages to attenuation control levels. The 2 - input NOR gates should be CMOS
(74C02 or equivalent) with 0 V applied to the positive supply terminal and -5 V on the negative
supply terminal.
~ 5kOhms
7
TriQuint Semiconductor, Inc. • Texas Facilities • (972) 995-8465 • www.triquint.com