The LMH6518 device is a digitally controlled variable gain amplifier whose total gain is varied from −1.16 dB to 38.8 dB for a 40 dB range in 2-dB steps. The −3-dB bandwidth is 900 MHz at all gains. Gain accuracy at each setting is typically 0.1 dB. When used in conjunction with TI's Gsample/second (Gsps) ADC with adjustable full-scale (FS) range, the LMH6518 gain adjustment accommodates full scale input signals from 6.8 mVPP to 920 mVPP to get 700 mVPP nominal at the ADC input. The auxiliary output (+OUT AUX and −OUT AUX) follows the main output and is intended for use in oscilloscope trigger function circuitry but may have other uses in other applications.
The LMH6518 gain is programmed through a SPI-1 compatible serial bus. A signal path combined gain resolution of 8.5 mdB is achieved when the device's gain and the Gsps ADC’s FS input are both manipulated. Inputs and outputs are DC-coupled. The outputs are differential with individual common mode (CM) voltage control (for main and auxiliary outputs), and have a selectable bandwidth limiting circuitry (common to both main and auxiliary) of 20, 100, 200, 350, 650, 750 MHz or full bandwidth.
|Part number||Order||PGA/VGA||Number of channels (#)||Vs (Min) (V)||Vs (Max) (V)||BW @ Acl (MHz)||Acl, min spec gain (V/V)||Gain (Max) (dB)||Slew rate (Typ) (V/us)||Operating temperature range (C)||Package Group||Package size: mm2:W x L (PKG)|
||VGA||1||4.75||5.25||900||0.87||38.8||760||-40 to 85||WQFN | 16||16WQFN: 16 mm2: 4 x 4 (WQFN | 16)|