ADL5605

Data Sheet

Rev. B | Page 16 of 18

EVALUATION BOARD

The schematic of the ADL5605 evaluation board is shown in

Figure 37. The evaluation board uses 25 mils wide, 50 Ω traces

and is made from IS410 material with a 20 mils gap to ground.

The evaluation board is tuned for operation at 943 MHz. The

inputs and outputs should be ac-coupled with appropriately

sized capacitors; therefore, for low frequency applications, the

value of C1 and C2 may need to be increased. DC bias is

provided to the output stage via an inductor (L1) connected

to the RFOUT pin. A bias voltage of 5 V is recommended.

The evaluation board has a short, non-50 Ω line on its output

to accommodate the four output pins and to allow for easier low

inductance output matching. The pads for Pin 9 to Pin 12 are

included on this microstrip line and are included in all matches.

The evaluation board uses numbers as identifiers to aid in the

placement of matching components at both the RF input and

RF output of the device. Figure 38 and Figure 39 show images

of the board layout.

RFIN

VCC3

VCC2

DISABLE

RFOUT

12

VBIAS

11

VCC

10

DISABLE

9

RFIN

1

2

3

4

ADL5605

8pF

C2

100pF

C1

100pF

N/A

C3

10pF

C4

OPEN

C10

OPEN

C5

100pF

C7

100pF

C8

0.01µF

C9

10µF

RFOUT

RFOUT

RFOUT

RFOUT

13

8

14

7

15

6

16

5

NC

NC

NC

NC

NC

NC

NC

NC

C6

0.01µF

C11

10µF

C12

100pF

C13

0.01µF

C14

10µF

L1

18nH

L2

1.6nH

VCC1

R4

OPEN

R1

0Ω

R5

OPEN

R2

0Ω

Figure 37. Evaluation Board, 943 MHz Frequency Tuning Band

Table 8. Evaluation Board Configuration Options, 943 MHz Frequency Tuning Band

Component

Function/Notes

Default Value

C1, C2

Input/output dc blocking capacitors.

C1, C2 = 100 pF

C3, C4, C5, C6, C7,

C8, C9, C10, C11,

C12, C13, C14

Power supply decoupling capacitors. Power supply decoupling capacitors are required to

filter out the high frequency noise on the power supply. The smallest capacitor should be the

closest to the ADL5605. The main bias that goes through RFOUT is the most sensitive to noise

because the bias is connected directly to the RF output.

C3 = 10 pF

C5, C7, C12 = 100 pF

C6, C8, C13 = 0.01 µF

C9, C11, C14 = 10 µF

C4, C10 = open

Input matching capacitor. To match the ADL5605 at the 943 MHz or 881 MHz frequency tuning

from the device so that the microstrip line can act as inductance for the matching network

(see Table 7). If space is at a premium, an inductor can take the place of the microstrip line.

Output matching capacitor. The output match is set for 943 MHz and is easily changed for

a specific distance from the device so that the microstrip line can act as inductance for the

matching network (see Table 7). If space is at a premium, an inductor can take the place of the

microstrip line. A short length of low impedance line on the output is embedded in the match.

L2

Output matching inductor. The output match is set for 943 MHz and is easily changed for other

frequency tuning bands. A high Q Coilcraft inductor with tight tolerance is recommended.

L2 = 1.6 nH HQ

L1

The main bias for the ADL5605 comes through L1 to the output stage. L1 should be high

impedance for the frequency of operation while providing low resistance for the dc current.

The evaluation board uses a Coilcraft 0603HP-18NX_LU inductor; this 18 nH inductor provides

some of the match at 943 MHz.

L1 = 18 nH

R1, R2, R4, R5

To provide bias to all stages through just one supply, set R1 and R2 to 0 Ω, and leave R4 and

R5 open. To provide separate bias to stages, set R1 and R2 to open and R4 and R5 to 0 Ω.

R1, R2 = 0 Ω

R4, R5 = open

Exposed Paddle

The paddle should be connected to both thermal and electrical ground.