MAX7422CUA+

Overview

The MAX7422CUA+ is a fifth-order, low-pass switched-capacitor filter with an elliptic response and a transition ratio of 1.6. It operates from a single +3V supply (range: 2.7V to 3.6V) and draws 3mA in operating mode, reducing to 0.2μA in shutdown mode. The corner frequency is adjustable from 1Hz to 45kHz via a clock input or internal oscillator set by an external capacitor. Key electrical parameters include a typical output offset voltage of ±4mV, a power-supply rejection ratio of 70dB, and a maximum capacitive load drive of 500pF. It is housed in an 8-pin μMAX package.

Feature Summary

• Elliptic filter response providing sharp rolloff and high stopband rejection
• Low-power operation with dedicated shutdown mode for minimal current draw
• Flexible clocking options using either an external clock signal or an internal oscillator

Applications

• ADC anti-aliasing
• DAC postfiltering
• CT2 base stations
• Speech processing

Procurement Notes

Verify the specific suffix 'CUA+' against the manufacturer's official documentation to confirm the commercial temperature range and RoHS compliance status. Ensure that the required operating voltage aligns with the device's +3V specification rather than the +5V variant. Cross-reference the pinout configuration to guarantee compatibility with the target PCB layout before finalizing procurement.

Selection Notes

Select this component when a steep roll-off characteristic is required within a low-voltage system architecture. The elliptic response distinguishes it from the Bessel and Butterworth variants in the same series. Confirm that the application can accommodate the necessary clock frequency generation circuitry, as the filter performance is directly dependent on the stability and accuracy of the clock source provided to the CLK pin.

Part Context

This device belongs to the MAX7418–MAX7425 family of fifth-order low-pass switched-capacitor filters manufactured by Analog Devices / Maxim Integrated. While other members of the series support +5V operation, the MAX7422 specifically utilizes a +3V supply. It shares the same 8-pin μMAX footprint and fundamental architectural design as its counterparts, differing primarily in the specified filter response type and operating voltage requirements.

Replacement Considerations

The MAX7422EUA serves as the industrial temperature grade replacement for the commercial grade MAX7422CUA+. Other family members like the MAX7425 offer a different elliptic transition ratio.