Data Sheet

ADL5906

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

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Rev. B | 8 of 30

Figure 2. Pin Configuration

Table 3. Pin Function Descriptions

Pin No.

Mnemonic

Description

1

TADJ/PWDN

Temperature Compensation/Shutdown. This is a dual function pin used for controlling temperature slope compensation at voltages <1.0

V and/or for shutting down the device at voltages >1.4 V. The temperature compensation voltage is generally set by connecting this pin

to VREF through a resistive voltage divider (see the Setting VTADJ section for additional information). See Figure 46 for an equivalent

circuit.

2, 13, 16

NIC

No Internal Connection. Do not connect to these pins. These pins are not internally connected.

3, 10

VPOS1, VPOS2

Power Supply. Because these pins are internally shorted, they must be connected to the same 5 V power supply. The power supply to

each pin must also be decoupled using 100 pF and 100 nF capacitors located as close as possible to the pins.

4, 9

GND1, GND2

Ground. Connect both GND1 and GND2 to system ground using a low impedance path.

5

CRMS

RMS Averaging Capacitor. Connect an rms averaging capacitor between CRMS and ground. See the Choosing a Value for CRMS

section for more information. See Figure 48 for an equivalent circuit.

6

VRMS

RMS Output. In measurement mode, this pin is connected to VSET either directly or through a resistor divider (when the slope is being

increased). In controller mode, this pin is used to drive the gain control input of a voltage variable attenuator (VVA) or variable gain

amplifier (VGA). See Figure 48 for an equivalent circuit.

7

VSET

Setpoint Input. In measurement mode, this pin is connected to VRMS either directly or through a resistor divider. In controller mode, the

voltage applied to this pin sets the decibel value of the required RF input level to balance the automatic power control loop. See Figure

47 for an equivalent circuit.

8

VTEMP

Temperature Sensor Output of 1.4 V at 25°C with a Coefficient of 4.8 mV/°C. See Figure 43 for an equivalent circuit.

11

VREF

Reference Voltage Output. This voltage reference has a nominal value of 2.3 V. This reference output voltage can be used to set the

voltage to the TADJ/PWDN and VTGT pins. See Figure 44 for an equivalent circuit. For optimal performance, bypass the VREF pin with

a minimum capacitance of 1 nF to ground.

12

VTGT

RMS Target Voltage. The voltage applied to this pin sets the target RF input at the output of the VGA that is also the rms squaring

circuit. The recommended voltage for VTGT is 0.8 V. Increasing VTGT above 0.8 V degrades the rms accuracy of the ADL5906. Reducing

VTGT below 0.8 V can improve the rms accuracy for signals with very high crest factors; however, it reduces the detection range of the

ADL5906. See Figure 49 for an equivalent circuit.

14, 15

RFIN+, RFIN−

RF Inputs. The RF inputs are normally applied single-ended with the RF input signal ac-coupled to RFIN+ and RFIN− ac-coupled to

ground. See Figure 42 for an equivalent circuit.

EPAD

The exposed pad on the underside of the device (EPAD) is also internally connected to ground and requires a good thermal and

electrical connection to the ground of the printed circuit board (PCB).