MAX7418EUA+

Overview

The MAX7418EUA+ 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 +5V supply (4.5V to 5.5V) and draws 3mA in active mode, reducing to 0.2μA in shutdown. The corner frequency is clock-tunable from 1Hz to 30kHz using a 100:1 clock-to-corner ratio. 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 features an offset adjust pin and is housed in an 8-pin μMAX package.

Feature Summary

• Provides sharp rolloff with high stopband rejection suitable for anti-aliasing and post-DAC filtering.
• Supports both internal oscillator and external clocking for precise corner-frequency control.
• Includes a low-power shutdown mode that significantly reduces supply current consumption.
• Features an offset adjust pin for DC output level tuning.

Applications

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

Procurement Notes

Verify the component matches the specific elliptic response variant required for the design. Confirm the operating voltage aligns with the +5V specification for this model. Ensure the industrial temperature range (-40°C to +85°C) meets system requirements. Check for RoHS compliance status indicated by the suffix.

Selection Notes

Select this part when a steep roll-off is needed compared to Bessel or Butterworth variants. Ensure the clock source can provide frequencies up to 3MHz for the full tuning range. Verify that the input signal amplitude stays within limits to maintain low distortion. Consider the 100:1 clock-to-corner ratio when designing the clock generation circuitry.

Part Context

This device belongs to the MAX7418–MAX7425 family of fifth-order low-pass switched-capacitor filters. The 'E' suffix denotes the extended industrial temperature range of -40°C to +85°C. The '+EA' indicates an 8-pin μMAX package with lead-free and RoHS-compliant materials.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.

FAQ

How is the corner frequency determined?

The corner frequency is set by the clock frequency divided by 100. It can be controlled via an external capacitor on the CLK pin for the internal oscillator or by an external clock signal.

What is the purpose of the OS pin?

The OS (Offset Adjust) pin allows for adjustment of the DC output level. It should be connected to COM if no offset adjustment is needed.

How does the shutdown mode function?

Driving the SHDN pin low activates shutdown mode, reducing supply current to 0.2μA and placing the output in a high-impedance state.