The ADL5336 consists of a pair of variable gain amplifiers (VGAs) designed for cascaded IF applications. The amplifiers have linear-in-dB gain control and operate from low frequencies to 1GHz. Their excellent gain conformance over the control range and flatness over frequency are due to Analog Devices, Inc, patented X-AMP architecture, an innovative technique for implementing high performance variable gain control.

Each VGA has 24dB of gain control range. Their maximum gain can be independently programmable over a 6dB range via the SPI. The VGAs can be cascaded to provide a total range of 48dB. When connected to a 50ohms source through a 1:4 balun, the gain is 6dB higher. The second VGA has an SPI programmable input switch that selects one of two external inputs.

When driven from a 200ohms source or from a 50ohms source through a 1:4 balun, the noise figure (NF) for the composite amplifier is 6.8dB at maximum gain. The output of each VGA can drive 100ohms loads to 5Vp-p maximum.

Each VGA has an independent square law detector for autonomous, automatic gain control (AGC) operation. Each detector setpoint can be programmed independently through the SPI from -24dBV to -3dBV in 3dB steps. When both VGAs are arranged in AGC mode and are programmed to the same setpoint, the composite NF increases to 9dB when backed off by 18dB from maximum gain.