Product Specification

SP4251

Page 4 of 8

Evaluation Kit

Figure 4. Evaluation Board Layouts

Figure 5. Evaluation Board Schematic

NOTES:

4.3 Er AND 2.1MIL Cu

THICKNESS.

3. ALL TRANSMISION LINES ARE:

33MIL WIDTH, 10MIL GAPS, 28MIL CORE DIELECTRIC

TO DAMAGE BY ELECTROSTATIC DISCHARGE (ESD)

2. CAUTION:

1. USE 101-0337-02 PCB.

CONTAINS PARTS AND ASSEMBLIES SUSCEPTIBLE

or GND

R1

DNI

C2

100pF

1

J3

SMASM

1

J4

SMASM

1

J5

SMASM

1

J2

SMASM

C1

100pF

1

J6

SMASM

2

V1

1

V2

3

RFC

6

GNDS1

7

GNDS2

8

RF2

4

N/C

5

RF1

U1

MSOP

1

1

3

3

5

5

7

7

2

2

4

4

6

6

8

8

10

10

9

9

J1

HEADER 2 X 5 PIN

R2

0 OHM

R3

0 OHM

The SPDT Switch Evaluation Kit board was

designed to ease customer evaluation of the

SP4251 SPDT switch. The RF common port is

connected through a 50

Ω transmission line to the

bottom SMA connector, J3. Port 1 and Port 2 are

connected through 50

Ω transmission lines to two

SMA connectors on either side of the board, J4 and

J2. A through transmission line connects SMA

connectors J5 and J6. This transmission line can be

used to estimate the loss of the PCB over the

environmental conditions being evaluated.

The board is constructed of a two metal layer FR4

material with a total thickness of 0.0322”. The

bottom layer provides ground for the RF

transmission lines. The transmission lines were

designed using a coplanar waveguide with ground

plane model using a trace width of 0.033”, trace

gaps of 0.010”, dielectric thickness of 0.028”, copper

thickness of 0.0021” and

ε

J1 provides a means for controlling the DC inputs to

the device. The second-to-bottom lower right pin

(J1-3) is connected to the device V1 input. The

second-to-top upper right pin (J1-7) is connected to

the device V2 input. Footprints for decoupling

capacitors are provided on both V1 and V2 traces. It

is the responsibility of the customer to determine

proper supply decoupling for their design application.

Removing these components from the evaluation

board has not been shown to degrade RF

performance.

Tel: +86-23-62808818

Fax: +86-23-62805284

www.sipatsaw.com / sawmkt@sipat.com