Features

• Continuous Time—No Clock
• Four 2nd Order Filter Sections, 20kHz to 300kHz
  Center Frequency
• Butterworth, Chebyshev, Elliptic or Equiripple
  Delay Response
• Lowpass, Bandpass, Highpass Responses
• 99dB Typical S/N, ±5V Supply (Q = 1)
• 93dB Typical S/N, Single 5V Supply (Q = 1)
• Rail-to-Rail Input and Output Voltages
• DC Accurate to 3mV (Typ)
• ±0.5% Typical Center Frequency Accuracy
• “Zero-Power” Shutdown Mode
• Single or Dual Supply, 5V to 10V Total
• Resistor-Programmable f_O, Q, Gain

Typical Application

Description

The LTC1562-2 is a low noise, low distortion continuous time filter with rail-to-rail inputs and outputs, optimized for a center frequency (f_O) of 20kHz to 300kHz. Unlike most monolithic filters, no clock is needed. Four independent 2nd order filter blocks can be cascaded in any combination, such as one 8th order or two 4th order filters. Each block’s response is programmed with three external resistors for center frequency, Q and gain, using simple design formulas. Each 2nd order block provides lowpass and bandpass outputs. Highpass response is available if an external capacitor replaces one of the resistors. Allpass, notch and elliptic responses can also be realized. The LTC1562-2 is designed for applications where dynamic range is important. For example, by cascading 2nd order sections in pairs, the user can configure the IC as a dual 4th order Butterworth lowpass filter with 90dB signal-to-noise ratio from a single 5V power supply. Low level signals can exploit the built-in gain capability of the LTC1562-2. Varying the gain of a section can achieve a dynamic range as high as 114dB with a ±5V supply. Other cutoff frequency ranges can be provided upon request. Please contact LTC Marketing.