HSMP-381C Datasheet, PDF (4/9 Pages) Broadcom Corporation. – Surface Mount RF PIN Low Distortion Attenuator Diodes

Typical Applications for HSMP-481x Low Inductance Series
Microstrip Series Connection for HSMP-481x Series
In order to take full advantage of the low inductance of the
HSMP-481x series when using them in series applications,
both lead 1 and lead 2 should be connected together, as
shown in Figure 7.
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1
2
HSMP-481x
Figure 6. Internal Connections.
Figure 7. Circuit Layout.
Microstrip Shunt Connections for HSMP-481x Series
In Figure 8, the center conductor of the microstrip
line is interrupted and leads 1 and 2 of the HSMP-481x
series diode are placed across the resulting gap. This forces
the 1.5 nH lead inductance of leads 1 and 2 to appear as
part of a low pass filter, reducing the shunt
parasitic inductance and increasing the maximum available
attenuation. The 0.3 nHof shunt inductance external to the
diode is created by the via holes, and is a good estimate
for 0.032" thick material.
1.5 nH
50 OHM MICROSTRIP LINES
R_j
1.5 nH
0.3 pF
PAD CONNECTED TO
GROUND BY TWO
VIA HOLES
Figure 8. Circuit Layout.
R_j ^0I.0_b0⁸_.9+ 2.5
0.3 nH
0.3 nH
Figure 9. Equivalent Circuit.
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