Description
The TMC2242A and TMC2242B are fixed-coefficient linear-phase half-band (low-pass) digital filters. They can be used to halve or double the sampling rate of a digital signal. When used as a decimating post-filter with a double-speed oversampling A/D converter, they greatly reduce the cost and complexity of anti-aliasing filters required ahead of the A/D converter. When used as an interpolating pre-filter with a double-speed oversampling D/A converter, the TMC2242A and TMC2242B significantly reduce the design complexity and production cost of reconstruction filters used on D/A outputs.

FEATUREs
• TMC2242A and TMC2242B are pin-compatible with TMC2242
• User selectable interpolate gain, -6 dB or 0 dB (2242B)
• 30, 40 and 60 MHz speed grades
• User selectable 2:1 decimation, 1:2 interpolation, and equal-rate filter modes
• Passband ripple < ±0.01 dB
• Stopband rejection 59.4 dB from 0.28 to 0.50 x fs
• Cascading two TMC2242A or TMC2242B meets CCIR 601 low-pass filter requirement
• Dedicated 12-bit 2's complement input data port and 16-bit output data port with user-selectable rounding from 9 to 16 bits
• Two's complement or offset binary output format
• Built-in limiter prevents overflow
• Single +5 Volt power supply operation
• Small 44-Lead PLCC and 44-Lead MQFP

APPLICATIONs
• Low-cost video filtering
• Chrominance bandwidth limiter
• Simple, inexpensive video D/A post-filters
• Reduced cost and complexity for A/D anti-aliasing filters
• High-performance digital low-pass filters
• Digital waveform reconstruction post-filtering
• Telecommunications
• Direct digital synthesis
• Radar