Low-voltage FIR filter for receivers used in communication systems
ABSTRACT The paper presents the principle and a possible implementation for an improved finite-impulse response (FIR) filter intended to be used with receivers operating in low voltage supply conditions. Basically, the main application of this filter is in the equalizer building block of a wireless receiver. To provide the filter with simple programmability through digital words, current dividers based on MOS transistors are included in its structure. Also, a very important block of the presented filter includes sample/hold circuits that must work at the same low supply voltage as the entire system. Low voltage operation of the proposed filter is achieved using the switched current technique.
- IEEE Journal of Solid-State Circuits 02/2001; · 3.06 Impact Factor
Conference Proceeding: Switched currents-a new technique for analog sampled-data signal processing[show abstract] [hide abstract]
ABSTRACT: A technique called `switched currents,' for analog sampled-data signal processing in the current domain, is introduced. A family of modules that are capable of various computational and memory functions is described. The modules are well suited to system building as demonstrated by the simulation of a sixth-order Chebyshev low-pass filter. Circuit techniques that enhance analog performance are offeredCircuits and Systems, 1989., IEEE International Symposium on; 06/1989
Conference Proceeding: An inherently linear and compact MOST-only current-divisiontechnique[show abstract] [hide abstract]
ABSTRACT: A technique is presented that uses the same MOS transistors for both division and switching functions, eliminating resistors or capacitors. Although an MOS-transistor exhibits a nonlinear relation between the current and voltage (even in the linear region), it is shown that the current division is inherently linear. The most important measurement results are shown. The dynamic range in the audio-band (0-20 kHz) is 103 dB with respect to a maximum input signal of 1 V<sub>rms </sub>. At 1 V<sub>rms</sub>, THD is below -80 dB over the audio band and below -85 dB under 3 kHz. As the unity-gain frequency of the opamps is 4.5 MHz, the bandwidth of the circuit is limited to 1.5 MHz. Attenuation accuracy is better than 0.15 dB up to -48 dB and better than 0.4 dB over the entire attenuation rangeSolid-State Circuits Conference, 1992. Digest of Technical Papers. 39th ISSCC, 1992 IEEE International; 03/1992