MAX7400ESA+T

Overview

The MAX7400ESA+T is an 8th-order, lowpass, elliptic switched-capacitor filter operating from a single +5V supply. It features a corner frequency range of 1Hz to 10kHz with a fixed 100:1 clock-to-corner ratio. The device provides -82dB stopband rejection and a transition ratio of 1.5. Supply current is 2mA in normal mode and 0.2µA in shutdown mode. It operates within a temperature range of -40°C to +85°C and is housed in an 8-pin SO package.

Feature Summary

• 8th-order elliptic response with sharp rolloff
• Low power consumption with dedicated shutdown mode
• Clock-tunable corner frequency via internal or external clocking
• Offset adjustment capability for DC level shifting

Applications

• ADC anti-aliasing
• Post-DAC filtering
• Speech processing
• Air-bag electronics
• CT2 base stations

Procurement Notes

Verify the specific suffix 'ESA' indicates the industrial temperature range (-40°C to +85°C) and SOIC-8 package configuration. Confirm RoHS compliance status through official manufacturer documentation prior to integration. Ensure the ordering code matches the required voltage and performance specifications exactly.

Selection Notes

Select this component when an 8th-order elliptic response with high stopband rejection is required. The +5V supply requirement distinguishes it from the +3V variants. Verify that the 100:1 clock-to-corner frequency ratio aligns with the system clock availability. Consider the shutdown feature if power conservation during idle periods is necessary.

Part Context

This part belongs to the MAX7400 family of switched-capacitor filters, which includes the MAX7403, MAX7404, and MAX7407. These devices share similar architectural characteristics but differ in operating voltage and filter transition ratios. The MAX7400 specifically offers the highest stopband rejection among the family members.

Replacement Considerations

MAX7403ESA (Elliptic r=1.2, +5V)

FAQ

How is the corner frequency determined?

The corner frequency is set by the clock frequency using a fixed 100:1 ratio (fC = fCLK / 100). It can be controlled via an external clock source or an internal oscillator defined by a capacitor on the CLK pin.

What is the purpose of the OS pin?

The OS pin allows for offset adjustment. Connecting it to COM sets the output offset to zero, while applying an external bias voltage enables DC level shifting at the output.

How does the shutdown mode function?

Driving the SHDN pin low activates shutdown mode, reducing supply current to 0.2µA and placing the output in a high-impedance state. Driving SHDN high returns the device to normal operation.