Manfred Punzenberger

A WiMedia/MBOA-Compliant CMOS RF Transceiver for UWB

A fully integrated WiMedia/MBOA-compliant RF transceiver for UWB data communication in the 3 to 5GHz band is presented. It is designed in a 0.13mum standard CMOS process with 1.5V single supply voltage. The NF is between 3.6 and 4.1dB over all 3 bands. On the TX side, the P1dB is 5dBm supporting an EVM of -28dB and up to -4dBm output power. A single-PLL LO generation is included

A 1.2-V low-power BiCMOS class AB log-domain filter

A third-order class AB current-mode Chebyshev filter based on the log-domain instantaneous companding principle and integrated in a 1-/spl mu/m BiCMOS process is presented. It has a nominal cutoff frequency of 320 kHz corresponding to a bias current of 1 /spl mu/A and can be frequency tuned over almost three decades up to about 10 MHz. It operates with a nominal supply voltage of 1.2 V maintaining a dynamic range at 1% total harmonic distortion (THD) of 65 dB. For cutoff frequencies in the range of 10 kHz, the supply voltage can be reduced down to 0.9 V. Typical to companding systems, the class AB filter shows a measured SNR versus input signal that saturates to a maximum value which for this particular realization is 52.5 dB. It has an active area of 0.55 mm/sup 2/ and dissipates 65 /spl mu/W, leading to a power consumption per pole and edge frequency of 67.7 pJ. These results demonstrate the potential of instantaneous companding filters for very low-voltage and low-power applications with moderate linearity and SNR requirements.

A new 1.2 V BiCMOS log-domain integrator for companding current-mode filters

New structures of differential and single-ended log-domain integrators are proposed, which can be used for very low supply voltage continuous-time filters. They offer a tuning range of several decades and operate at minimum supply voltages down to 1 V. The single-ended version allows very simple filter structures, whereas the differential one can be driven by signal currents which are much larger than the bias currents (class AB operation).

Low-voltage log-domain signal processing in CMOS and BiCMOS

This paper presents the most important properties of log-domain filters for the realization of low-voltage and low power analog signal processing circuits. The noise behavior is discussed and the advantage of the combination of companding and class AB operation is highlighted. Examples of BiCMOS and CMOS realizations operating at supply voltages as low as 1 V are presented.

Low-voltage companding current-mode integrators

A family of differential companding current-mode integrators is proposed, which can be used as building blocks for high frequency continuous-time filters. They offer a tuning range of several decades and can be driven by signal currents which are much larger than the biasing currents (class AB operation). The minimum supply voltage ranges from 1.8 V down to 1 V, depending on the circuit architecture.

A 1.2 V BiCMOS class AB log-domain filter

Companding improves dynamic range in situations with restricted signal swing, such as in low-voltage circuits, without the need to reduce noise at the cost of increased power dissipation. The log-domain filter principle achieves instantaneous signal companding by taking advantage of exponential device characteristics. Thanks to the high compression ratio, voltage swing and frequency tuning become almost independent of supply voltage, which can be reduced to the minimum required for proper operation. The combination of instantaneous companding with class AB operation permits processing of signals much larger than the bias level and hence increases dynamic range substantially. Class AB log-domain filters are suited to low-voltage and low power applications with moderate signal-to-noise ratio (SNR) and linearity requirements. The authors present a 3/sup rd/-order Chebyshev filter which is based on an integrator and implemented in a 1 /spl mu/m BiCMOS process. The filter can be tuned over more than 3 decades with cut-off frequencies ranging from 10 kHz to 15 MHz at supply voltages between 0.9 V and 2 V. For a 1.2 V supply, cut-off frequencies up to about 1 MHz are achieved.

Noise in instantaneous companding filters

The noise performance of instantaneous companding filters in the presence of a low frequency input signal is investigated. Log-domain integrators are taken as examples for more detailed considerations. The results are extended to a 3rd-order Chebyshev filter and are in good agreement with measurements of a BiCMOS implementation.

A 1-V CMOS log-domain integrator

A novel circuit implementation of a CMOS log-domain integrator is presented. Unlike most other implementations, it does not require placing of MOSFETs in separated wells, and therefore allows very compact filters, which are fully compatible with modern standard CMOS technologies. Besides the saving of chip area, this also helps to reduce parasitic capacitances. The most important advantage of this circuit is the very low minimum required supply voltage of only two saturation voltages plus one gate-to-source voltage of a weakly inverted MOSFET. This is fully compatible with the minimum required supply voltage of digital gates implemented in the same technology. The integrator was used as a building block for a 5th-order Bessel filter, which was simulated with the transistor parameters of a 0.5 /spl mu/m CMOS technology.

A compact low-power BiCMOS log-domain filter

A third-order Chebyshev filter based on the log-domain principle and integrated in a 1-/spl mu/m BiCMOS process is presented. It has a nominal cutoff frequency of 320 kHz corresponding to a bias current of 1 /spl mu/A, and can be frequency tuned over almost three decades up to about 10 MHz. It operates with a nominal supply voltage of 1.2 V, maintaining a dynamic range (DR) at 1% THD of 57 dB. For cutoff frequencies in the range of 10 kHz, the supply voltage can be reduced down to 0.9 V. The filter occupies an active area of 0.25 mm/sup 2/ and dissipates 23 /spl mu/W, corresponding to a power consumption per pole and edge frequency of only 24 pJ. These results demonstrate the potential of log-domain filters for very low-voltage and low-power applications.

1-V log-domain filters

Note: (invited) Reference EPFL-CONF-149548 Record created on 2010-06-24, modified on 2017-05-12