MAX291CPA

Overview

The MAX291CPA is an 8th-order, lowpass, switched-capacitor filter in the MAX291 series. It provides a maximally flat Butterworth response with a clock-tunable corner frequency range of 0.1Hz to 25kHz. The device operates on a single +5V supply or dual ±5V supplies and requires no external resistors or capacitors for its core filtering function. It features an internal oscillator or external clock input, maintaining a 100:1 clock-to-corner-frequency ratio. An uncommitted operational amplifier is included for post-filtering or anti-aliasing tasks. The component is housed in an 8-pin Plastic DIP package and supports an operating temperature range from 0°C to +70°C.

Feature Summary

• 8th-order lowpass Butterworth filter providing maximally flat passband response
• Clock-tunable corner frequency adjustable from 0.1Hz to 25kHz
• Integrated uncommitted operational amplifier for auxiliary filtering applications

Applications

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

Procurement Notes

Verify that the specific ordering suffix CPA corresponds to the 8-pin Plastic DIP package configuration. Confirm the commercial temperature rating (0°C to +70°C) aligns with the intended environmental requirements. Ensure the design accommodates the required clock signal specifications and power supply constraints defined in the electrical characteristics table.

Selection Notes

Select the MAX291CPA when a maximally flat Butterworth response is required for instrumentation signals. Choose this part over the MAX292 series if phase linearity and fast settling are less critical than stopband attenuation. Verify that the application can provide a stable clock signal between 10kHz and 2.5MHz to achieve the desired cutoff frequencies within the specified 0.1Hz to 25kHz range.

Part Context

The MAX291CPA belongs to the MAX291/MAX292/MAX295/MAX296 family of 8th-order lowpass switched-capacitor filters. While the MAX291 and MAX295 offer Butterworth responses, the MAX292 and MAX296 provide Bessel characteristics. This specific model represents the commercial grade version packaged in an 8-pin DIP format, distinct from the extended temperature E-series or military MJA variants.

Replacement Considerations

Direct functional replacements include the MAX291EPA for extended temperature operation and the MAX291CSA for surface-mount SO packaging. For Bessel response requirements, consider the MAX292CPA. Higher frequency variants such as the MAX295CPA support corner frequencies up to 50kHz.