General Description

The MAX7400/MAX7403/MAX7404/MAX7407 8th-order, lowpass, elliptic, switched-capacitor filters (SCFs) operate from a single +5V (MAX7400/MAX7403) or +3V (MAX7404/MAX7407) supply. These devices draw 2mA of supply current and allow corner frequencies from 1Hz to 10kHz, making them ideal for low-power anti-aliasing and post-DAC filtering applications. They feature a shutdown mode that reduces the supply current to 0.2µA.

Two clocking options are available: self-clocking (through the use of an external capacitor) or external clocking for tighter cutoff-frequency control. In addition, an offset adjustment pin (OS) allows for the adjustment of the DC output level.

The MAX7400/MAX7404 provide 82dB of stopband rejection and a sharp rolloff with a transition ratio of 1.5. The MAX7403/MAX7407 provide a sharper rolloff with a transition ratio of 1.2, while still delivering 60dB of stop band rejection. The fixed response of these devices simplifies the design task to corner-frequency selection by setting a clock frequency. The MAX7400/MAX7403/MAX7404/MAX7407 are available in 8-pin SO and DIP packages.

Features

♦ 8th-Order Lowpass Elliptic Filter

♦ Low Noise and Distortion

   -82dB THD + Noise (MAX7400)

♦ Clock-Tunable Corner Frequency (1Hz to 10kHz)

♦ 100:1 Clock-to-Corner Ratio

♦ Single-Supply Operation

   +5V (MAX7400/MAX7403)

   +3V (MAX7404/MAX7407)

♦ Low Power

   2mA (Operating Mode)

   0.2µA (Shutdown Mode)

♦ Available in 8-Pin SO and DIP Packages

♦ Low Output Offset: ±5mV

Applications

   ADC Anti-Aliasing

   Speech Processing

   Post-DAC Filtering

   Air-Bag Electronics

   CT2 Base Stations