MAX271ENG

Overview

The MAX271ENG is a digitally-programmed, dual second-order continuous-time lowpass filter manufactured by Analog Devices Inc./Maxim Integrated. It operates within a supply voltage range of ±2.375V to ±8V and supports an operating temperature range from -40°C to +85°C. The device features two independent filter sections with programmable cutoff frequencies selectable between 1kHz and 25kHz via 7-bit digital inputs. It provides a typical dynamic range of 96dB and includes an integrated track-and-hold circuit. The component is housed in a 20-pin PDIP package.

Feature Summary

• Dual second-order continuous-time lowpass filters with no clock noise
• Integrated track-and-hold circuit for signal sampling
• Digitally programmable cutoff frequencies from 1kHz to 25kHz
• Low-power shutdown mode reducing current consumption below 15µA

Applications

• Anti-aliasing filtering for data acquisition systems
• Output smoothing for digital-to-analog converters
• Low-noise signal conditioning applications
• Cascaded higher-order filter configurations

Procurement Notes

Verify the specific ordering suffix against official manufacturer documentation to confirm package type and temperature grade. Ensure compatibility with system logic levels, as digital inputs are TTL and CMOS compatible. Confirm RoHS compliance status if required by assembly specifications. Cross-reference pin assignments with the datasheet to prevent interface errors during integration.

Selection Notes

Select this component when continuous-time filtering without clock-related aliasing is required. The MAX271ENG is suitable for applications needing precise analog signal conditioning before digitization. Consider the integrated track-and-hold feature if sample-and-hold functionality is needed within the filter stage. Verify that the required cutoff frequency falls within the 1kHz to 25kHz programmable range.

Part Context

The MAX271ENG belongs to the MAX270/MAX271 family of digitally-programmed filters. Unlike switched-capacitor filters, these devices use continuous-time architecture to eliminate clock noise. The MAX271 variant specifically integrates a track-and-hold circuit, distinguishing it from the MAX270 which contains an uncommitted operational amplifier instead.

Replacement Considerations

The MAX270ENG serves as a functional alternative within the same family but lacks the internal track-and-hold circuit, offering an uncommitted op amp instead. Designers must verify pinout compatibility and software control differences when substituting components.