LMF100CIWMX

Overview

The LMF100CIWMX is a dual high-performance switched capacitor filter manufactured by Texas Instruments. It integrates two independent second-order filter blocks within a single 20-pin SOIC package, enabling the realization of fourth-order biquadratic functions. The device operates on a wide supply voltage range from 4 V to 15 V and supports clock frequencies up to 3.5 MHz. Key electrical characteristics include a typical DC offset voltage of ±5 mV in 50:1 mode, a clock-to-center frequency ratio accuracy of ±0.2%, and an f0 × Q range extending up to 1.8 MHz. It provides low crosstalk of -60 dB and features outputs for lowpass, bandpass, notch, allpass, and highpass filtering.

Feature Summary

• Integrates two independent general-purpose switched capacitor filter sections capable of realizing various classical filter responses including Butterworth, Bessel, Elliptic, and Chebyshev.
• Offers flexible configuration through external resistors and capacitors, allowing each block to perform multiple filtering functions such as lowpass, bandpass, highpass, notch, and allpass.
• Features pin-compatible design with the industry-standard MF10 while providing significantly improved performance metrics regarding offset voltage and operating frequency range.

Applications

• Audio signal processing and equalization circuits
• Communication systems requiring precise frequency selection
• Instrumentation and telemetry data acquisition

Procurement Notes

Verify component authenticity by checking the manufacturer's marking code against official documentation. Confirm the ordering suffix matches the required temperature grade and packaging format. Ensure compliance with RoHS directives if applicable to the specific production batch. Review the datasheet for any recent product change notifications that may affect mechanical or electrical specifications prior to final procurement.

Selection Notes

Select this component when designing filters requiring high accuracy and low offset without the complexity of discrete active RC implementations. Consider the maximum clock frequency limits relative to the desired center frequency and Q factor. Evaluate the power supply requirements to ensure they fall within the specified 4 V to 15 V range. Assess thermal management needs based on the junction-to-ambient thermal resistance provided in the datasheet.

Part Context

The LMF100 series represents a legacy line of analog filter ICs from Texas Instruments, originally developed to replace discrete active RC filters. The CIWMX variant specifically denotes the industrial temperature range version packaged in a surface-mount SOIC format with tape-and-reel delivery. This family was designed to offer a cost-effective and space-saving alternative to continuous-time integrated filters.

Replacement Considerations

The LMF100 is marked as Not Recommended for New Designs. Direct pin-compatible replacements are not explicitly listed in the provided documentation. Designers should evaluate modern alternatives from Texas Instruments or other manufacturers that offer updated performance characteristics and long-term availability guarantees.

FAQ

What is the maximum clock frequency supported by the LMF100?

The LMF100 supports clock frequencies up to 3.5 MHz, depending on the supply voltage and operating conditions.

How does the LMF100 differ from the MF10?

While pin-compatible, the LMF100 offers improved performance with a wider supply voltage range, lower offset voltage, higher operating frequency, and greater f0 × Q range compared to the MF10.

Can the LMF100 implement fourth-order filters?

Yes, by cascading its two internal second-order filter sections, the LMF100 can realize fourth-order biquadratic filter functions.