MAX297 Datasheet

• 8th-Order Lowpass Elliptic Filters
• Clock-Tunable Corner-Frequency Range:
  • 0.1Hz to 50kHz (MAX297)
• No External Resistors or Capacitors Required
• Internal or External Clock
• Clock to Corner Frequency Ratio
  • 50:1 (MAX297)
• Operate with a Single +5V Supply or Dual ±5V Supplies
• Uncommitted Op Amp for Anti-Aliasing or Clock-Noise Filtering
• 8-Pin DIP and 16-Pin Wide SO Packages

• Anti-Aliasing
• DAC Post-Filtering
• Data-Acquisition Systems
• Voice/Data Signal Filtering

The MAX297 are easy-to-use, 8th-order, lowpass, elliptic, switched-capacitor filters that can be set up with corner frequencies from 0.1Hz to 50kHz (MAX297).

The MAX297's 1.5 transition ratio provides sharp rolloff and -80dB of stopband rejection. All three filters have fixed responses, so the design task is limited to selecting the clock frequency that controls the filter's corner frequency.

An external capacitor is used to generate a clock using the internal oscillator, or an external clock signal can be used. An uncommitted op amp (noninverting input grounded) is provided for building a continuous-time lowpass filter for post-filtering or anti-aliasing. Steep rolloff and high order make these filters ideal for anti-aliasing applications that require maximum bandwidth, and for communication applications that require filtering signals in close proximity within the frequency domain.

The MAX297 are available in 8-pin DIP and 16-pin wide SO packages, delivering aggressive performance from a tiny area.