MAX7401CPA+

Overview

The MAX7401CPA+ is an 8th-order, lowpass, Bessel switched-capacitor filter in an 8-pin plastic DIP package. It operates from a single +5V supply with a typical supply current of 2mA and a shutdown current of 0.2µA. The device features a clock-to-corner frequency ratio of 100:1, allowing corner frequencies from 0.001kHz to 5kHz. Key electrical parameters include a total harmonic distortion plus noise of -82dB, an output offset voltage of ±5mV (typical), and an internal oscillator frequency determined by an external capacitor.

Feature Summary

• Provides 8th-order lowpass Bessel filtering characteristics for fast settling and low overshoot.
• Supports both self-clocking via external capacitor and external clock inputs for precise control.
• Includes a dedicated shutdown mode to minimize power consumption during idle periods.
• Features an offset adjust pin for DC output level tuning.

Applications

• ADC anti-aliasing
• Post-DAC filtering
• Speech processing

Procurement Notes

Verify the component authenticity through official manufacturer channels or authorized distributors. Confirm that the ordering suffix matches the specific temperature range and package variant required for your design. Ensure compliance with relevant environmental standards before finalizing procurement orders.

Selection Notes

Select this component when an 8th-order Bessel response is required for signal conditioning. Consider the MAX7405 if a +3V supply is preferred. Evaluate the need for external versus internal clocking based on the required corner frequency stability and available system resources.

Part Context

This part belongs to the MAX7401/MAX7405 family of switched-capacitor filters. It shares functional similarities with other Maxim Integrated SCF devices but is distinct in its specific 8th-order Bessel topology and single-supply operation requirements.

Replacement Considerations

Direct replacements within the same family include the MAX7405 variants for different supply voltages. Cross-family replacements require careful evaluation of order, response type, and pin compatibility.

FAQ

How is the internal oscillator frequency determined?

The internal oscillator frequency is set by connecting a capacitor between the CLK and GND pins. For the MAX7401, the frequency is approximately 38,000 divided by the capacitance value in picofarads.

What is the purpose of the OS pin?

The OS pin allows for adjustment of the DC output level. It can be connected to COM for no adjustment or biased externally to shift the output offset voltage.

Can the MAX7401 operate with dual supplies?

Yes, the MAX7401 can operate with dual supplies (e.g., ±2.5V). In this configuration, the COM pin should be connected to system ground.