Krohn Hite 31A-1

DESCRIPTION The Model 31A Series high-pass, elliptical filter/voltage gain amplifier is one of many plug-in filter cards used in the Models 3905B/3905C/3916B/3916C Programmable Filter Systems chassis.

FILTER FEATURES As an elliptical filter, the Model 31A Series has a tunable cutoff frequency range from 0.01Hz to 99kHz, a rolloff rate of 115dB/octave and a minimum stopband attenuation of >80dB. Passband ripple is typically 0.22dB.

The 31A provides either a single-ended or differential input with a common mode rejection of >60dB. Input gains up to 40dB in 10dB steps and output gains to 20dB are also provided. The 31A will accept input signals of ±10V peak at 0dB gain and has selectable ac or dc coupling. Overload detectors are standard and assist the user in detecting excessive input signals or incorrect gain settings.

AMPLIFIER FEATURES The 31A is also a programmable voltage gain amplifier for applications that require a low noise amplifier. The amplifier has a bandwidth of 1MHz and gains to 60dB, selectable in 10dB steps, and a wideband noise of <20 V.

APPLICATIONS Typical applications for the Model 31A are: removing line related frequencies, enhancing signal-to-noise ratio, distortion testing, low noise pre-amplification and many more. Plug-in cards offering other types of filters with different frequency ranges, slopes and number of channels are also available.

SPECIFICATIONS

FUNCTION: High-pass filter; voltage gain amplifier.

FILTER MODE Type: 7-pole, 6-zero elliptical. Attenuation: 115dB/octave. Passband Ripple: 0.22dB typical, 0.4dB max. Tunable Frequency Range f_c:    Model 31A-1: 1Hz to 99kHz.    Model 31A-2: 0.1Hz to 9.9kHz.    Model 31A-3: 0.01Hz to 990Hz.