VCA2611 Datasheet | Burr-Brown

URES q LOW-NOISE PREAMP: - Low Input Noise: 0.95n V/√Hz - Active Termination Noise Reduction - Switchable Termination Value - 80MHz Bandwidth - 5d B to 25d B Gain - Differential In and Out q LOW-NOISE VARIABLE GAIN AMPLIFIER: - Low-Noise VCA - Up to 40d B Gain Range - 40MHz Bandwidth - Differential In and Out q LOW CROSSTALK: 66d B at Max Gain, 5MHz q HIGH-SPEED VARIABLE GAIN ADJUST q SWITCHABLE EXTERNAL PROCESSING DESCRIPTION The VCA2616 and VCA2611 are dual, Low-Noise Preamplifiers (LNP), plus low-noise Variable Gain Amplifiers (VGA). The VCA2611 is an upgraded version of the VCA2616. The only difference between the VCA2616 and the VCA2611 is the input structure to the LNP. The VCA2616 is limited to - 0.3V negativegoing input spikes; the VCA2611 is limited to - 2.0V negativegoing input spikes. This change allows the user to use slower and less expensive input clamping diodes prior to the LNP input. In some designs, input clamping may not be required. The bination of Active Termination (AT) and Maximum Gain Select (MGS) allow for the best noise performance. The VCA2616 and VCA2611 also feature low crosstalk and outstanding distortion performance. The LNP has differential input and output capability and is strappable for gains of 5d B, 17d B, 22d B, or 25d B. Low input impedance is achieved by AT, resulting in as much as a 4.6d B improvement in noise figure over conventional shunt termination. The termination value can also be switched to acmodate different sources. The output of the LNP is available for external signal processing. The variable gain is controlled by an analog voltage whose gain varies from 0d B to the gain set by the MGS. The ability to program the variable gain also allows the user to optimize dynamic range. The VCA input can be switched from the LNP to external circuits for different applications. The output can be used in either a single-ended or differential mode to drive highperformance Analog-to-Digital (A/D) converters, and is cleanly limited for...