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Alpha Industries, Inc. [781] 935-5150

• Fax [617] 824-4579 • Email sales@alphaind.com • www.alphaind.com

Specifications subject to change without notice. 1/01A

Low Capacitance Plastic Packaged PIN Diodes

SMP1321 Series

Series Resistance vs. Current @ 100 MHz

0.01

0.1

1

10

100

Forward Current (mA)

0.1

1

10

100

0

1

2

5

10

20

50

Capacitance vs. Reverse Voltage

0

0.2

0.1

0.4

0.6

0.5

0.3

0.8

0.7

Reverse Voltage (V)

1 MHz–1 GHz

400

500

600

700

800

900

1000

DC Characteristic

0.01

0.1

1

10

100

Forward Voltage (mV)

0

500

1000

1500

2000

Conductance vs. Frequency

and Reverse Voltage

Frequency (MHz)

0 V

10 V

40 V

0

100

200

300

400

500

600

700

800

Typical Performance Data

RR

R

R

R

-55°C

-15°C

+25°C

+65°C

+100°C

(mA)

(

Ω

Ω)(Ω

Ω)(Ω

Ω)(Ω

Ω)(Ω

Ω)

0.02

47.400

50.000

56.300

61.500

65.100

0.10

12.000

12.600

13.900

15.400

16.400

0.30

5.200

5.400

5.800

6.400

6.900

0.50

3.600

3.800

4.100

4.500

4.800

1.00

2.400

2.500

2.600

2.800

3.100

10.00

1.030

1.040

1.040

1.070

1.150

20.00

0.871

0.888

0.873

0.889

0.956

100.00

0.669

0.659

0.642

0.645

0.695

Resistance vs. Temperature @ 500 MHz

SMP1321-007

In the -007 configuration of the SOT-23 package, the package

inductance is effectively reduced to 0.4 nH, in comparison to

the 1.5 nH value of the standard configuration. This lower

inductance will be particularly beneficial when the diodes are

used as shunt connected switches at frequencies higher than

500 MHz, where inductance is the primary limitation on

maximum switch isolation.

To achieve the effective 0.4 nH, the SOT-23 package must

be inserted in the microstrip circuit board with a gap in the

trace, as shown in the

figure. Because of the

polarity

of

the

diode

junction, this low inductance

feature is only realizable with

the cathode connected to

ground.

Ground

Gap