Data Sheet

ADL6012

Rev. 0 | Page 21 of 24

ENABLE INTERFACE

ENBL (Pin 1) provides the ability to enable or disable the

device to conserve power. Connect ENBL to VPOS or above

1.5 V to enable the device. Connect ENBL to ground or below

0.5 V to disable the device. Do not exceed VPOS by 0.3 V or

below ground by more than 0.3 V. Leaving the ENBL pin open

turns off the device.

Faster turn on time can be achieved using a smaller capacitor

value on the VOCM pin. The capacitor must be large enough to

minimize the common-mode noise.

DECOUPLING INTERFACE

DCPL (Pin 10) is connected to the internal bias node. DCPL

provides the stable output common-mode voltage. Connect a

0.1 µF capacitor from the DCPL pin to ground for the best

common-mode noise performance.

PCB LAYOUT RECOMMENDATIONS

Parasitic elements of the PCB, such as coupling and radiation,

limit accuracy at very high frequencies. Ensure low loss power

transmission from the connector to the internal circuit of the

ADL6012. Microstrip and CPWG are popular forms of trans-

mission lines because of their ease of fabrication and low cost

(see Figure 65 and Figure 66). In the ADL6012 evaluation

board (ADL6012-EVALZ), a grounded CPWG (GCPWG)

minimizes radiation effects and provides the maximum band-

width by using two rows of grounding vias on both sides of the

signal trace.

15mils

RO4003

VIA

VIA

5mils

8mils

5mils

Figure 65. CPWG Interface Design to RFIN for RO4003 Material (Not to Scale)

Figure 66 shows the CPWG structure of the PCB layout.

Microwave material RO4003 with 8 mil thickness is used in the

ADL6012-EVALZ between the RF signal and ground layer.

VIA

VIA

RFCM

RFCM

RFIN

Figure 66. Suggested RF Input Layout

SYSTEM CALIBRATION AND MEASUREMENT

ERROR

To achieve the highest detection accuracy, perform calibration

at the board level because output voltages vary from device to

device. Each device can be calibrated with two or more points

in the linear region of the transfer function by applying CW

input at different levels. The slope and intercept can be

calculated as described in this section. Linear regression over

the calibration range is recommended for best accuracy.

Board level calibration is a simple method to improve the

accuracy of the envelope detection. With a minimum of two

point or more calibration, the entire detection range of the

device can be calibrated to the highest accuracy possible.

The measured ADL6012 transfer function at 18 GHz is shown

in Figure 67 and the envelope output and linearity conformance

error vs. the input peak voltage at various temperatures from

−40°C to +125°C. Error over temperature is relative to the

room 25°C curve.

4.0

0

0.5

2.5

1.0

3.0

1.5

2.0

3.5

3

–3

–2

2

–1

0

1

0

2.0

1.4

1.8

1.0

0.6

1.2

1.6

0.8

0.4

0.2

+125°C

+105°C

+85°C

+25°C

–40°C

–55°C

Figure 67. Differential VENV± Output Voltage and Error vs. Input Peak

Voltage at 18 GHz