7426PC

Overview

The MAX7426PC is a fifth-order, lowpass, elliptic switched-capacitor filter IC manufactured by National Semiconductor. It operates from a single +5V supply and draws only 0.8mA of supply current. The device allows corner frequencies from 1Hz to 12kHz, making it ideal for low-power post-DAC filtering and anti-aliasing applications. It can be put into a low-power mode, reducing supply current to 0.2µA. Two clocking options are available: self-clocking (through the use of an external capacitor) or external clocking for tighter cutoff-frequency control. An offset-adjust pin allows for adjustment of the DC output level. The MAX7426 delivers 37dB of stopband rejection and a sharp rolloff with a transition ratio of 1.25. Its fixed response limits the design task to selecting a clock frequency.

Feature Summary

• Fifth-order, lowpass, elliptic switched-capacitor filter
• Single +5V supply operation
• Low-power mode capability
• Self-clocking or external clocking options

Applications

• Post-DAC filtering
• Anti-aliasing applications

Procurement Notes

Verify the manufacturer as National Semiconductor, now part of Analog Devices. Confirm the package type is DIP-16. Ensure the operating temperature range is -40°C to +85°C. Check for RoHS compliance if required. Verify the supply voltage is +5V. Confirm the corner frequency range is 1Hz to 12kHz. Ensure the stopband rejection is 37dB. Verify the transition ratio is 1.25. Check for any obsolescence notices.

Selection Notes

Select the MAX7426PC when a fifth-order, lowpass, elliptic switched-capacitor filter is needed. Consider its single +5V supply operation and low power consumption. Evaluate its suitability for post-DAC filtering and anti-aliasing applications. Assess the need for self-clocking or external clocking options. Determine if the 37dB stopband rejection and 1.25 transition ratio meet the design requirements. Verify the DIP-16 package availability.

Part Context

The MAX7426PC belongs to the MAX7426/MAX7427 family of fifth-order, lowpass, elliptic switched-capacitor filters. These devices are designed for low-power post-DAC filtering and anti-aliasing applications. They operate from a single +5V (MAX7426) or +3V (MAX7427) supply. The family offers corner frequencies from 1Hz to 12kHz and can be put into a low-power mode. Two clocking options are available: self-clocking or external clocking. An offset-adjust pin allows for DC output level adjustment. The devices deliver 37dB of stopband rejection and a sharp rolloff with a transition ratio of 1.25.

Replacement Considerations

The MAX7427 is a compatible alternative operating from a +3V supply instead of +5V.