MAX7491EEE+T

Overview

The MAX7491EEE+T is a dual universal switched-capacitor filter housed in a 16-pin QSOP package. It operates from a single +3V supply (2.7V to 3.6V) and features two identical low-power, rail-to-rail 2nd-order filter sections. The device supports center frequencies up to 40kHz with a fixed clock-to-center frequency ratio of 100:1. It offers high accuracy with Q and clock-to-center frequency errors within ±0.2%. Key electrical parameters include a maximum clock frequency of 4MHz, shutdown current below 1µA, and an operating temperature range of -40°C to +85°C.

Feature Summary

• Dual 2nd-order filter sections capable of generating bandpass, lowpass, highpass, and notch functions simultaneously.
• Internal rail splitter enables precise common voltage for single-supply operation without external biasing components.
• Supports both internal oscillator and external clock inputs for flexible cutoff frequency control.
• Low-power shutdown mode reduces supply current to less than 1µA when disabled.

Applications

• ADC anti-aliasing filters
• Post-DAC filtering
• Tunable active filters
• Multipole filter cascading

Procurement Notes

Verify the specific suffix EEE indicates the extended industrial temperature range (-40°C to +85°C) and the + symbol confirms lead-free/RoHS compliance. Confirm the package type is 16-pin QSOP. Ensure the design utilizes a single +3V supply, as the MAX7491 variant is distinct from the MAX7490 which requires +5V. Check for availability constraints as indicated by distributor listings.

Selection Notes

Select the MAX7491EEE+T when a single +3V supply is required for low-voltage applications. Choose this component over the MAX7490 if system power constraints limit the supply voltage to approximately 3V. The EEE suffix is necessary for designs requiring operation in temperatures down to -40°C. Verify that the required center frequency does not exceed 40kHz given the internal clock limitations.

Part Context

This component belongs to the MAX7490/MAX7491 family of dual universal switched-capacitor filters manufactured by Analog Devices/Maxim Integrated. The MAX7491 variant is specifically optimized for single +3V supply operation, whereas the MAX7490 is designed for +5V supplies. Both share identical pinouts and functional architectures but differ in power requirements and internal biasing characteristics.

Replacement Considerations

The MAX7490EEE+ is a direct hardware-compatible alternative if the application can support a +5V supply instead of +3V. Other MAX749x variants with different suffixes may offer commercial temperature ranges or different packaging options but must be verified for electrical compatibility regarding supply voltage and performance specifications.