ADL5240

Rev. 0 | Page 22 of 24

NC

VDD

NC

NC

NC

DSAOUT

NC

NC

NC

NC

VDD

DSAIN

ADL5240

NC

NC

NC

NC

R2

VDD

100pF

470nH

0.1µF

C2

0

0

0

0

DNI

DNI

DNI

DNI

DNI

DNI

1

17

18

2

20

21

23

24

3

4

5

6

8

AMPIN

1

2

3

4

5

6

7

8

9

VDD

1

2

R9

C9

R8

R7

R6

R5

R4

R3

C10

C11

C13

C14

C15

CLK

DATA

LE

C4

AMPOUT

R17

0.1µF

DSAIN

C1

19

DNI

DNI

DNI

7

C12

0

0

0

0

DNI

DSAOUT

100pF

L1

0.1µF

R12

R15

R14

C3

22

C8

3

DNI

R13

0

R10

R11

0

R16

DNI

0

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

68pF

1.2nF

VDD

1µF

R1

VCC

C7

C6

C5

DNI

AGND

S1

Figure 39. ADL5240 Evaluation Board

Table 8. Evaluation Board Configuration Options

Component

Function/Notes

Default Value

C1, C2

Input/output dc blocking capacitors for DSA.

C1, C2 = 100 pF

C3, C4

Input/output dc blocking capacitors for AMP.

C3, C4 = 0.1 μF

C5, C6, C7

Power supply decoupling for amplifier. The bias associated with the AMPOUT pin is

the most sensitive to noise because the bias is connected directly to the output. The

smallest capacitor (C7) should be the closest to the AMPOUT pin.

C5 = 1 μF

C6 = 1.2 nF

C7 = 68 pF

C8

Power supply decoupling for the DSA.

C8 = 0.1 μF

C9, C10, C11, C12, C13,

C14, C15

Capacitors of the RC filter on the digital signals leading to the SPI chip.

C9, C10, C11, C12,

C13, C14, C15 = open

L1

The bias for the amplifier comes through L1 when VCC is connected to a 5 V supply.

L1 should be high impedance for the frequency of operation while providing low

resistance for the dc current.

L1 = 470 nH

R1, R2

Resistors to connect the supply for the amplifier and the DSA to the same VDD plane.

R1, R2 = open

R3, R4, R5, R6, R7, R8, R9

Resistors of the RC filter on the digital signals leading to the SPI chip.

R3, R4, R5, R6, R7, R8,

R9 = 0 Ω

R10, R11, R14, R15

These resistors are used to terminate RF coupling onto the traces and to close the loop.

R10, R11, R14, R15 =

0 Ω

R12, R13, R16, R17

R12 and R16 are replaced with capacitors, and R13 and R17 are replaced with 0 Ω to

close the loop.

R12, R13, R16, R17 =

open

S1

Switch to change between the serial mode and parallel mode of operation. Connect

to supply for parallel mode and to ground for serial mode operation.

S1 connected to

ground