ADL5604

Rev. 0 | Page 21 of 24

Table 7. Evaluation Board Configuration Options, 2140 MHz

Component

Function/Notes

Default Value

C1, C2

Input/output dc blocking capacitors at 2140 MHz. C3 provides dc blocking; therefore, a jumper is

installed in place of C1.

C1 = 0 Ω,

C2 = 22 pF

C3, C4

Input matching capacitors. The input match is set for 2140 MHz but is easily changed for other

frequencies. C3 is set at a specific distance from C4 so that the microstrip line can act as inductance for

part of the match. If space is at a premium, an inductor can take the place of the microstrip line. The

ADL5604 is sensitive to the input match; therefore, the tolerance of these components and their

placement must be tight.

C3 = 1.3 pF HQ,

C4 = 2.7 pF HQ

C5

Output matching capacitor. The output match is set for 2140 MHz but is easily changed for other

frequencies. The tolerance for this capacitor should be tight. C5 is set at a specific distance from the

input; therefore, the microstrip line can act as inductance for part of the match. If space is at a

premium, an inductor can take the place of the microstrip line. There is a short length of low

impedance line on the output that is embedded in the match. The ADL5604 is less sensitive to the

output match than the input match, but the tolerance still must be tight.

C5 = 2.4 pF

L1, L2, R9, R10

The main bias for the ADL5604 comes through L1 to its output. 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-16NX_H inductor. It is a 16 nH inductor, which provides some of

the match at 2140 MHz. As the operating frequency gets lower, the inductance must increase,

but as the inductance increases, the current is more limited for a 0603 package. R9 and R10 can

be removed and L2 added to allow for low frequency operation. L2 has the footprint for a

Coilcraft SLC7530D-101MLB (0.4 μH).

L1 = 16 nH,

L2 = open,

R9 = 0 Ω,

R10 = 0 Ω

C6, C7, C8, C9,

C10, C11, C12,

C14, C15

Power supply decoupling. The need for power supply decoupling capacitance is based on the

noise and potential for noise on the power supply. The smallest capacitor should be the closest

to the ADL5604. The main bias that goes through RFOUT is the most sensitive to noise because

the bias is connected directly to the output.

C6, C9, C11 = 10nF,

C7, C10, C12, C14,

C15 = 0.1uF,

C8 = 10 uF

R6, R8

R6 and R8 can be removed to eliminate any parasitic elements of VBIAS and VCC2 if a fast

response time is required.

R6 = 0 Ω,

R8 = 0 Ω

R2, R4, R5

The ADL5604 can be shut down using VBIAS alone or VBIAS and VCC2. The ADL5604 has a

shutdown current of 13 mA when only VBIAS is used. The shutdown current is < 1 μA if VBIAS and

VCC2 are used. However, VCC2 draws 5 mA when biased, setting the current drive capability of

the shutdown controller. R2, R4, and R5 allow custom configuration of the shutdown.

R2, R5 = 0 Ω,

R4 = open

U2, R1, R3

If VCC2 is used to shut down the ADL5604, 5 mA must be sourced when the part is enabled. U2,

R1, and R3 are configured as a buffer to source the 5 mA.

U2 = AD8009,

R1 = 3.01 Ω,

R3 = open

Exposed Paddle

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

Figure 44. Evaluation Board Layout, Topside

Figure 45. Evaluation Board Layout, Bottom Side