Data Sheet

ADL5903

Rev. B | Page 19 of 20

EVALUATION BOARD SCHEMATIC AND CONFIGURATION OPTIONS

Figure 49. Evaluation Board Schematic

Table 5. Evaluation Board Configuration Options

Component

Description

Default Value

RFIN, R208

RF input. R208 is a shunt input termination to optimize low frequency input

return loss.

RFIN = SMA connector,

R205, R206, S201

Device enable interface. Header S201 configures the enable network. Pin 2

and Pin 3 of S201 enable the resistive divider network. R205 and R206 form a

resistive divider network to step down the voltage provided by VPOS for an

optimal enable setpoint condition.

R205 = 100 kΩ,

R206 = 100 kΩ,

S201 = Jumper Pin 2 and

Jumper Pin 3

C201, C202

Power supply decoupling. The nominal supply decoupling consists of a

100 pF and a 0.1 μF capacitor placed near the device.

C201 = 100 pF,

C202 = 0.1 µF

C209

CRMS for rms averaging. Set the value of the rms averaging capacitor on the

peak-to-average ratio of the input signal and based on the desired output

response time and residual output noise. See the Choosing a Value for CRMS

section for more information.

C209 = 0.1 µF

R202, C203A

Bypass capacitor connection for on-chip regulator. R202 and C203A are

connected to the CREG pin to provide decoupling for the internal regulator.

R202 = 4.02 Ω, C203A = 0.1 µF

R204, C210

RMS output. R204 and C210 provide options for output filtering and to mimic

system load conditions.

R204 = 0 Ω, C210 = DNI1

C203, C204, C204A, C205,

C205A, R203, R207, R209

Test header interface.

C203, C204, C204A, C205, C205A,

R203, R207, R208, R209 = DNI1

EP

Exposed pad. The exposed pad is soldered to a ground pad, which provides

both a thermal ground and an electrical ground.

1

DNI = do not install.

VOUT

RFIN

1

2

3

4

COMM

RFIN

ADL5903

8

7

6

5

CRMS

CREG

VRMS

NIC

VPOS

ENBL

VPOS

VPOS

C201

100pF

C202

0.1μF

4.02Ω

DNI

ENBL

R208

DNI

R207

DNI

R202

R206

100kΩ

R205

100kΩ

R209

DNI

R204

0Ω

OUT

C210

DNI

C203

DNI

C203A

0.1μF

COMM

EP

P201 (24-PIN TEST HEADER)

1

2

S201

3

1

2

3

4

5

6

7

8

9 10 11 12

1

2

3

4

5

6

7

8

9 10 11 12

B

A

C205A

DNI

TO P201

R203

DNI

TO P201

TO P201

C205

DNI

C204A

DNI

C204

DNI

TO P201

0.1μF

C209