ADPA1112 datasheet(19/21 Pages) AD

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Data Sheet

ADPA1112

APPLICATIONS INFORMATION

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Rev. 0 | 19 of 21

BASIC CONNECTIONS

The basic connections to operate the ADPA1112 are shown in

Figure 59. Decouple the VDD1, VDD2, and VGG1 pins as shown

in Figure 59. The gate voltage for all stages (−3.0 V to −1.0 V for

biased operation and −4.0 V for pinch off) is applied to the VGG1

pin. A VDD of 28 V nominal is applied to the VDD1 and VDD2

pins. Pin 1, Pin 2, and Pin 6 are designated as NIC pins. Although

these NIC pins are not internally connected, the NIC pins were all

connected to ground during the characterization of the device.

To turn on the ADPA1112, take the following steps:

1. Connect the power supply grounds to GND.

2. Set VGG1 to −4V.

3. Set VDD1 and VDD2 to 28V.

4. Adjust VGG1 more positive to achieve an IDQ of 600mA, approxi-

mately −2V.

5. Apply to the RF signal.

To turn off the ADPA1112, take the following steps:

1. Turn off the RF signal.

2. Set VGG1 to −4V to achieve an IDQ of 0mA.

3. Set the voltage on VDD1 and VDD2 to 0V.

4. Increase VGG1 to 0V.

SOLDERING AND ASSEMBLY

CONSIDERATIONS

The ADPA1112 is a nonhermetic air cavity device. The body of the

package normally sits within a cutout in the PCB that allows direct

access to a heatsink beneath the PCB. To facilitate good thermal

and electrical conduction to the heatsink, a shim of electrically and

thermally conductive material, such as Heat-Spring indium from

Indium Corporation, can be used. (Alternatively, electrically and

thermally conductive paste or grease can be used). The shim is

placed between the heatsink and the bottom of the package base.

Then, the package can be attached to the heatsink using screws

(typically). Once attached with the screw hardware, the pins must

be flush with the PCB, which allows the leads to be soldered to the

PCB pads.

ADPA1112 Datasheet(PDF) 19 Page - Analog Devices