DEMO CIRCUIT 1538A LT6350CMS8 QUICK START GUIDE LT6350CMS8 Low Noise Single-Ended to Differential Amplifier SAR ADC Driver DESCRIPTION Demonstration Circuit 1538A supports the LT6350, a Design files for this circuit board are available. Call the Low Noise Single Ended to Differential Amplifer / SAR LTC factory. ADC Driver. The LT6350 contains an un-dedicated open- L , LT, are registered trademarks of Linear Technology Corporation. Other product names may be trademarks of the companies that manufacture the products. loop Opamp1, and a dedicated inverting Opamp2 in a gain of -1. Opamp1 has Rail to Rail inputs and output. Opamp2 has a Rail to Rail ouput. See Figure 1. PERFORMANCE SUMMARY Specifications are typical at T = 25C, Vs = +/-5V A SYMBOL PARAMETER CONDITIONS, COMMENTS TYP UNITS V Supply Voltage Range Single Supply 2.7V to 12V V S Split Supply +/-1.35V to +/-6V V Vcm Input Voltage Range Op Amp 1 Rail to Rail V Op Amp 2 Vs- +1.5V to Vs+ -0.1V V BW -3dB Bandwidth Small signal, differential output 33 MHz Vout Output Voltage Swing Each output, to either rail, no load 55 mV I Supply Current Vs = +/-5V 4.8 mA CC Figure 1. LT6350 Block Diagram . Opamp1 is an undedicated low noise opamp. Opamp2 is a dedicated invertor. 1 LT6350CMS8 OPERATING PRINCIPLES Conversion of single ended signals to differential is a an already connected internal invertor, Opamp2. In the basic function. It may be desired for improved transmis- simplest configuration, with Opamp1 in a gain of 1, the sion characteristics over twisted pair, or for driving SAR conversion to differential causes an effective gain of 2 ADCs which prefer differential inputs. The LT6350 overall. makes the single-ended to conversion easy by providing QUICK START PROCEDURE Demonstration circuit 1538 is shipped with the jumpers set for Single Supply, DC coupled operation, with Opamp1 configured in a gain of 1 (OUT1 shorted to IN1). As the intended application is for single ended inputs, only one in- put BNC connector is installed (J1) and this is the exciatation path for Opamp1s non-inverting input +IN1. To support Opamp1 in inverting or other applications, a footprint for another BNC was included (J3) for user installation. Figure 2. Proper Connections for Single Supply Operation (DMMs optional). The function generator should be set up to operate around a positive 2V DC offset. For split supply operation, set JP6 to Split Supply and connect a negative supply to the V- turret. 2