DESCRIPTION
Likewise, by using the LF2242 as an interpolating pre-filter with a D/A converter, the corresponding analog reconstruction post-filter circuitry can be simplified. The coefficients of the LF2242 are fixed, and the only user programming required is the selection of the mode (interpolate, decimate, or passthrough) and rounding. The asynchronous three-state output enable control simplifies interfacing to a bus. Data can be input into the LF2242 at a rate of up to 40 million samples per second. Within the 40 MHz I/O limit, the output sample rate can be onehalf, equal to, or two times the input 12/16-bit Half-Band Interpolating/ Decimating Digital Filter LF2242 FEATURES
u 40 MHz Clock Rate u Passband (0 to 0.22fS) Ripple: ±0.02 dB u Stopband (0.28fS to 0.5fS) Rejection: 59.4 dB u User-Selectable 2:1 Decimation or 1:2 Interpolation u 12-bit Two’s Complement Input and 16-bit Output with User-Selectable Rounding, 8- to 16-Bits u User-Selectable Two’s Complement or Inverted Offset B...