TI LMH6518SQ/NOPB

The LMH6518 is a digitally controlled variable gain amplifier with a total gain range from -1.16 dB to 38.8 dB, adjustable in 2-dB steps over a 40-dB gain range. The -3-dB bandwidth is 900 MHz at all gain settings. Gain accuracy at each setting point is typically 0.1 dB. When used with TI's Gsps ADC featuring an adjustable full-scale (FS) range, the LMH6518's gain adjustment can accommodate full-scale input signals from 6.8 mVpp to 920 mVpp to achieve a nominal 700 mVpp at the ADC input. The auxiliary outputs (+OUT AUX and -OUT AUX) follow the main outputs and are intended for use in oscilloscope trigger function circuits, but may serve other purposes in different applications.

The LMH6518 gain is programmed via an SPI-1 compatible serial bus. When the device gain and the Gsps ADC's FS input are adjusted simultaneously, a combined signal path gain resolution of 8.5 mdB can be achieved. Both inputs and outputs are DC-coupled. The outputs are differential with independent common-mode (CM) voltage control (for main and auxiliary outputs respectively), and include an optional bandwidth limiting circuit (shared between main and auxiliary outputs) with selectable bandwidths of 20, 100, 200, 350, 650, 750 MHz, or full bandwidth.

• Oscilloscope programmable gain amplifier
• Differential ADC driver
• High-frequency single-ended to differential conversion
• Precision gain control applications
• Medical applications
• RF/IF applications