ADL5331

1 MHz至1.2 GHz的VGA 30 dB增益控制范围 1 MHz to 1.2 GHz VGA with 30 dB Gain Control Range

Product Details

The is a high performance, voltage-controlled variable gain amplifier/attenuator for use in applications with frequencies up to 1.2 GHz. The balanced structure of the signal path maximizes signal swing, eliminates common-mode noise and minimizes distortion while it also reduces the risk of spurious feed-forward at low gains and high frequencies caused by parasitic coupling.

The 50 Ω differential input system converts the applied differential voltage at INHI and INLO to a pair of differential currents with high linearity and good common-mode rejection. The signal currents are then applied to a proprietary voltage- controlled attenuator providing precise definition of the overall gain under the control of the linear-in-dB interface. The GAIN pin accepts a voltage from 0 V at a minimum gain to 1.4 V at a full gain with a 40 mV/dB scaling factor over most of the range.

The output of the high accuracy wideband attenuator is applied to a differential transimpedance output stage. The output stage provides a differential output at OPHI and OPLO, which must be pulled up to the supply with RF chokes or a center-tapped balun.

The ADL5331 consumes 240 mA of current including the output pins and operates off a single supply ranging from 4.75 V to 5.25 V. A power-down function is provided by applying a logic low input on the ENBL pin. The current consumption in power-down mode is 250 μA.

The ADL5331 is fabricated on an Analog Devices, Inc., proprietary high performance, complementary bipolar IC process. The ADL5331 is available in a 24-lead 4 mm × 4 mm, Pb-free LFCSP package and is specified for operation from ambient temperatures of −40°C to +85°C. An evaluation board is also available.

**Applications**

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Transmit and receive power control at RF and IF

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CATV distribution

### Features and Benefits

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Voltage-controlled amplifier/attenuator

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Operating frequency: 1 MHz to 1.2 GHz

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Optimized for controlling output power

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High linearity: OIP3 47 dBm @ 100 MHz

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Output noise floor: −149 dBm/Hz @ maximum gain

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Input impedance: 50 Ω

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Output impedance: 20 Ω

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Wide gain-control range: 30 dB

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Linear-in-dB gain control function: 40 mV/dB

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Single-supply voltage: 4.75 V to 5.25 V