Data Sheet

ADL5910

Rev. 0 | Page 19 of 22

EVALUATION BOARD

The ADL5910-EVALZ is a fully populated, 4-layer, FR4

evaluation board that includes an SPST and an asymmetrical

power coupling circuit. In its default configuration, the circuit

operates as a complete input protection circuit that can connect

to the input of a receiver or a power amplifier. A single 3.3 V

power supply (VPOS) and GND test loops provide power for

the complete board.

The primary signal path on the evaluation board is from

the RFIN_SW SMA connector to the RFOUT_SW SMA

connector. In this path, there is a HMC550A SPST switch

and an asymmetrical power splitter/coupler. The insertion

loss of the splitter/coupler is 1.72 dB, which combines with

the insertion loss of HMC550A (0.7 dB typical) to product a

total signal path loss of approximately 2.5 dB.

The coupling factor of the splitter/coupler is 20 dB, that is, the

signal level between R47 and R45 with respect to the signal level

at the input of R46.

The coupled signal is applied at the RF input of ADL5910. The

threshold level of the ADL5910 is set by an on-board mechanical

potentiometer, R8 (an external voltage can also be applied to the

VNEXT SMA connector or to the VIN− yellow test loop).

When the RF input level exceeds the equivalent voltage level on

VIN−, the Q output of the ADL5910 opens the HMC550A,

which increases the signal path attenuation to between −40 dB

and −20 dB (based on the input frequency). The inline attenuation

is the off isolation of the switch. An overdrive trigger also turns

on a flashing LED on the evaluation board that is driven by the

Q output of the ADL5910. To reset the ADL5910 outputs, press

the S1 push down switch.

The evaluation board can also be configured for standalone testing

of the ADL5910 by removing R16, placing a 0 Ω resistor on the

R9 pad, and applying the RF input signal on the RFIN_ADL5910

SMA connector.

The evaluation board also includes a series of pads in the signal

chain that are adjacent to the RF input of the ADL5910. Place

capacitors and inductors on these pads to improve RF flatness

(see the Applications Information section).

Detailed configuration options for the evaluation board are

listed in Table 6.

1000pF

0.01µF

HMC550AE

0.47µF

0Ω

0Ω

DNI

TBD0603

1.1kΩ

B3S-1000

0.1µF

100pF

JOHNSON142-0701-851

4.02Ω

1kΩ

ADL5910

YEL

YEL

0.47µF

YEL

YEL

0Ω

4.99Ω

DNI

TBD0402

220Ω

62Ω

4.99Ω

JOHNSON142-0701-851

JOHNSON142-0701-851

JOHNSON142-0701-851

10kΩ

1.1kΩ

1.1kΩ

09 03201 02

YEL

0.1µF

1kΩ

SSL-LX5093BSRD

0.47µF

DNI

82.5Ω

0Ω

DNI

DNI

TBD0402

DNI

TBD0402

0Ω

DNI

TBD0402

DNI

TBD0402

TBD0402

TBD0402

100Ω

C111

R17

R15

R10

R14

C5

R13

L2

C4

R12

R11

L1

DS1

U1

VIN–

TCAL

R36

R9

C1

C14

R2

5 4 3 2

5 4 3 2

5 4 3 2

5 4 3 2

R46

R47

R45

R16

Q

ENBL

S2

R1

RFIN_SW

RFOUT_SW

RFIN_ADL5910

VNEXT

R5

C3

U23

C115

C11

C12

R3

S1

R4

C13

C2

R7

R8

R6

Q

VPOS

VPOS

VPOS

16

3

15

1

13

12

14

4

1

1

1

1

1

2

3

1

1

1

1

1

4

2

5

6

3

1

3

1

4

2

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

AGND

VIN–

RST

ENBL

Q

DECL

TCAL

RFIN

AGND

VCTL

VDD

GND

GND

RF1

RF2

AGND

AGND

AGND

AGND

AGND

Q

Q

Q

Figure 23. Evaluation Board Schematic