AD8372

Data Sheet FEATURES Dual independent digitally controlled VGA Differential input and output 150 Ω differential input Open-collector differential output 7.8 dB noise figure to 100 MHz @ maximum gain HD2/HD3 better than 77 dBc for 1 V p-p differential output −3 dB bandwidth of 130 MHz 41 dB gain range 1 dB step size ± 0.2 dB Serial 8-bit bidirectional SPI control interface Wide input dynamic range Pin-programmable output stage Power-down feature Single 5 V supply: 106 mA per channel 32-lead LFCSP, 5 mm × 5 mm package APPLICATIONS Differential ADC drivers CMTS upstream direct sampling receivers CATV modem signal scaling Generic RF/IF gain stages Single-ended-to-differential conversion GENERAL DESCRIPTION The AD8372 is a dual, digitally controlled, variable gain amplifier (VGA) that provides precise gain control, high IP3, and low noise figure. The excellent distortion performance and moderate signal bandwidth make the AD8372 a suitable gain control device for a variety of multichannel receiver applications. For wide input dynamic range applications, the AD8372 provides a broad 41 dB gain range. The gain is programmed through a bidirectional 4-pin serial interface. The serial interface consists of a clock, latch, data input, and data output lines for each channel. The AD8372 provides the ability to set the transconductance of the output stage using a single external resistor. The RXT1 and RXT2 pins provide a band gap derived stable reference voltage of 1.56 V. Typically 2.0 kΩ sh...