5th-Order, Lowpass, Elliptic, Switched-Capacitor Filters

The MAX7426/MAX7427 5th-order, lowpass, elliptic, switched-capacitor filters (SCFs) operate from a single +5V (MAX7426) or +3V (MAX7427) supply. The devices draw only 0.8mA of supply current and allow corner frequencies from 1Hz to 12kHz, making them ideal for low-power post-DAC filtering and anti-aliasing applications. They can be put into a low-power mode, reducing 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. An offset-adjust pin allows for adjustment of the DC output level.

The MAX7426/MAX7427 deliver 37dB of stopband rejection and a sharp rolloff with a transition ratio of 1.25. Their fixed response limits the design task to selecting a clock frequency.

Applications

* ADC Anti-Aliasing Filter * Post-DAC Filtering Speech Processing

* 5th-Order, Elliptic Lowpass Filters

* Low Noise and Distortion: -80dB THD + Noise

* Clock-Tunable Corner Frequency (1Hz to 12kHz)

* Single-Supply Operation

* +5V (MAX7426)

* +3V (MAX7427)

* Low Power

* 0.8mA (Operating Mode)

* 0.2µA (Shutdown Mode)

* Available in 8-Pin µMAX®/PDIP Packages

* Low Output Offset: ±4mV