MAX7491CEE+T

Overview

The MAX7491CEE+T is a dual universal switched-capacitor filter from Analog Devices Inc./Maxim Integrated, housed in a 16-pin QSOP package. Designed for single-supply operation at +3V, it integrates two identical low-power, rail-to-rail 2nd-order filter sections. The device supports internal or external clocking with a fixed clock-to-center frequency ratio of 100:1 and an internal sampling-to-center frequency ratio of 200:1. It achieves high accuracy with Q and clock-to-center frequency errors limited to ±0.2%. The center frequency range extends up to 40kHz, and the component includes a low-power shutdown mode drawing less than 1µA.

Feature Summary

• Dual 2nd-Order Filter Architecture
• Rail-to-Rail Input and Output Operation
• High Accuracy Frequency Control
• Low-Power Shutdown Mode

Applications

• Tunable Active Filters
• Multipole Filters
• ADC Anti-Aliasing
• Post-DAC Filtering
• Phase-Locked Loops (PLLs)

Procurement Notes

Verify the specific suffix CEE+T against official documentation to confirm the commercial temperature range and lead-free status. Ensure the +3V supply requirement aligns with system power rails. Confirm the 16-pin QSOP package dimensions match PCB layout constraints. Validate that the internal oscillator or external clock source meets the required duty cycle specifications for optimal performance.

Selection Notes

Select the MAX7491 over the MAX7490 when the system operates on a single +3V supply rather than +5V. Consider the internal oscillator capability if external clock generation is undesirable, noting the dependency on external capacitance values. Evaluate the need for cascading sections to achieve higher-order filtering requirements such as Chebyshev or Butterworth responses. Assess the impact of resistor tolerances on Q accuracy for precision applications.

Part Context

This component belongs to the MAX7490/MAX7491 family of dual universal switched-capacitor filters. The MAX7491 variant is specifically optimized for lower voltage operation compared to the MAX7490. Both devices share identical pinouts and functional architectures, differing primarily in their specified supply voltage ranges. The family is designed for applications requiring flexible filter topologies within a compact surface-mount package.

Replacement Considerations

The MAX7490 is electrically similar but requires a +5V supply instead of +3V. Verify compatibility regarding supply voltage levels before substitution. No other direct pin-compatible replacements are documented in the provided datasheet.