MAX291EPA+

Overview

The MAX291EPA+ is an 8th-order, lowpass, switched-capacitor Butterworth filter in an 8-pin Plastic DIP package. It provides a maximally flat passband response with a clock-tunable corner frequency range of 0.1Hz to 25kHz. The device operates on single +4.75V to +11V or dual ±2.375V to ±5.5V supplies and features an internal oscillator or external clock input with a 100:1 clock-to-corner-frequency ratio. It includes an uncommitted op amp for additional filtering and requires no external resistors or capacitors for the main filter section.

Feature Summary

• 8th-Order Lowpass Butterworth Filter
• Clock-Tunable Corner Frequency
• Internal Oscillator Capability
• Uncommitted Operational Amplifier

Applications

• ADC Anti-Aliasing Filter
• Noise Analysis
• DAC Post-Filtering
• 50Hz/60Hz Line-Noise Filtering

Procurement Notes

Verify the specific suffix 'EPA+' against the manufacturer's current ordering guide to confirm the exact temperature range (-40°C to +85°C) and RoHS compliance status. Cross-reference the component marking with official datasheet pinout diagrams to ensure authenticity before integration into production designs.

Selection Notes

Select this component when a fixed 8th-order Butterworth response is required without external passive components. Ensure the application supports the necessary clock frequency generation, as the corner frequency is strictly dependent on the CLK input. Verify that the supply voltage requirements align with the available power rails in the target system design.

Part Context

This part belongs to the MAX291/MAX292/MAX295/MAX296 family of switched-capacitor filters. The MAX291 specifically implements a Butterworth response, distinguishing it from the MAX292 which offers a Bessel response. The 'E' suffix denotes the extended industrial temperature range, while 'PA' indicates the 8-pin plastic DIP packaging format.

Replacement Considerations

MAX291CPA (Commercial Temperature Range)

FAQ

How is the corner frequency determined?

The corner frequency is set by the clock frequency applied to the CLK pin, maintaining a 100:1 ratio between the clock and the corner frequency.

Can the internal oscillator be used?

Yes, an external capacitor connected to the CLK pin can be used to generate the clock signal using the internal oscillator circuitry.

What is the purpose of the OP OUT pin?

The OP OUT pin connects to an uncommitted operational amplifier that can be configured for anti-aliasing or clock-noise filtering applications.