TMC2242AKTCT

Overview

The TMC2242AKTC is a fixed-coefficient linear-phase half-band digital filter manufactured by Fairchild Semiconductor. It operates on a single +5 V supply and accepts 12-bit two's complement input data at clock frequencies up to 30 MHz, corresponding to its speed grade. The device outputs saturated 16-bit data rounded to user-selectable resolutions between 9 and 16 bits. It supports three operational modes: 2:1 decimation, 1:2 interpolation, and equal-rate filtering. The filter response exhibits passband ripple of less than 0.01 dB and stopband rejection exceeding 59.4 dB from 0.28 to 0.50 times the sampling frequency. It is housed in a 44-lead MQFP package.

Feature Summary

• Implements a 55-tap finite impulse response (FIR) filter with symmetric coefficients for linear phase characteristics.
• Provides user-selectable interpolation gain settings of -6 dB or 0 dB via hardware control pins.
• Includes built-in limiter circuitry to prevent overflow during signal processing operations.
• Supports dual output data formats including signed two's complement and inverted offset binary.

Applications

• Low-cost video filtering and chrominance bandwidth limiting
• Anti-aliasing filters for oversampling analog-to-digital converters
• Reconstruction post-filters for digital-to-analog converters
• Digital waveform reconstruction and direct digital synthesis

Procurement Notes

Verify the specific speed grade suffix required for the target clock frequency, as the base model designation does not indicate performance limits. Confirm that the 44-lead MQFP package matches the printed circuit board footprint requirements. Ensure the operating temperature range aligns with the commercial specification limits defined in the datasheet.

Selection Notes

Select the appropriate speed grade suffix based on the maximum system clock frequency to ensure timing compliance. Choose between the A and B variants depending on the required interpolation gain setting. Verify that the input data format matches the supported 12-bit two's complement standard. Check power supply decoupling requirements against the specified pin capacitance values.

Part Context

This component belongs to the TMC2242 family of digital half-band interpolating and decimating filters. The series includes variants with different speed grades and package types, such as PLCC and MQFP configurations. The TMC2242A and TMC2242B models are pin-compatible, allowing for design flexibility regarding gain settings while maintaining identical physical interfaces.

Replacement Considerations

TMC2242BKTC serves as a functional substitute within the same product family. Both components share identical pinouts and core filtering capabilities. Differences exist primarily in the interpolation gain configuration options available to the user through control inputs.