This survey deals with 1/f noise in homogeneous semiconductor samples. A distinction is made between mobility noise and number noise. It is shown that there always is mobility noise with an /spl alpha/ value with a magnitude in the order of 10/sup -4/. Damaging the crystal has a strong influence on /spl alpha/, /spl alpha/ may increase by orders of magnitude. Some theoretical models are briefly discussed none of them can explain all experimental results. The /spl alpha/ values of several semiconductors are given. These values can be used in calculations of 1/f noise in devices. >

1/f Noise Sources

High performance voltage output filter realizations using second generation voltage conveyor

This paper describes the front-end of a fully integrated analog interface for 300 MSps, high-definition video digitizers in a system on-chip environment. The analog interface is implemented in a 1.2 V, 65-nm digital CMOS process and the design minimizes the number of power domains using core transistors only. Each analog video receiver channel contains an integrated multiplexer with a current-mode dc-clamp, a programmable gain amplifier (PGA) and a pseudo second-order RC low-pass filter. The digital charge-pump clamp is integrated with low-voltage bootstrapped tee-switches inside the multiplexer, while restoring the dc component of ac-coupled inputs. The PGA contains a four-stage fully symmetric pseudo-differential amplifier with common-mode feedforward and inherent common-mode feedback, utilized in a closed loop capacitive feedback configuration. The amplifier features offset cancellation during the horizontal blanking. The video interface is evaluated using a unique test signal over a range of video formats for INL+/DNL+, INL-/DNL-. The 0.07-0.39 mV INL, 2-70 μV DNL, and 66-74 dB of SFDR, enable us to target various formats for 9-12 bit Low-voltage digitizers.

1.2-V Analog Interface for a 300-MSps HD Video Digitizer in Core 65-nm CMOS

Motorola Inc.

Biosensor signal improvement using current mirror topology for dissolved oxygen measurement

The offer of information grows rapidly in mobile markets. The DVB-H standard as a part of DVB-T is an important carrier of information to a broad spectrum of consumers. New, cheap and robust receivers have to be developed, especially for handheld devices. We propose a high-speed operational amplifier for a low-pass filter in a direct conversion receiver. In order to integrate the receiver on a System on Chip, it is designed in 65nm low-power CMOS. The operational amplifier is a four-stage feed-forward nested Miller compensated fully differential operational amplifier with an AB output stage. A gain-bandwidth product of 1GHz and a gain of 58dB is reached. A load capacitance of 5pF can be driven at a phase margin of 62deg.

A 1GHz-GBW operational amplifier for DVB-H receivers in 65nm CMOS

DVB-H is a new standard for mobile TV, hence new receivers for the integration in SoCs are needed, to offer mobile TV on various mobile devices. In DVB-H receivers a direct conversion receiver is often used that transfers the RF signal directly into the base band. We propose a fully differential operational amplifier for the low-pass filter in a DVB-H receiver in 65nm low-power CMOS technology. The operational amplifier has four stages including two feed-forward paths and a class AB output stage, which are nested Miller compensated. The operational amplifier reaches a gain-bandwidth product of 1GHz and a phase margin of 60° at a load of 4pF. Furthermore, it has a gain of 68dB and consumes 9.6mA at a supply voltage of 1.2V.

A fully differential operational amplifier for a low-pass filter in a DVB-H receiver

A 3rd-order continuous-time current-mode filter in 65 nm CMOS technology is presented. The filter has a switchable cut-off frequency between 1.1 and 4.4 MHz and is designed for software defined radio on chip (SDR) solutions. An innovative extension to structures in literature is proposed, that allows saving chip area at low cut-off frequencies. Furthermore a mathematical estimation is presented to show the usability of the structure. The realized chip has an active area of 350 μm × 220 μm and consumes 12.3 mW at 1.2 V. The dynamic range for a bandwidth of 1.1 MHz is 77.2 dB, the in-band output current noise is $$31.16\,\hbox{pA}/\sqrt{\hbox{Hz}}$$ and the IIP3 is 1.8 mAp.

A current-mode continuous-time filter for software defined radio solutions

Voltage-mode filters and especially their linearity and dynamic range suffer from the low supply voltages of deep-sub-micron and nanometer CMOS. This fact served as motivation to investigate current-mode filters with the hope for a better linearity and larger dynamic range. Current-mode filters also may allow saving of current-to-voltage and voltage-to-current converters compared to the case when voltage mode filters are used in combination with current-mode mixer and current-steering digital-analog converter for instance. A lower power consumption then should be obtainable. This chapter will give on overview on current-mode filters described in literature and will introduce new current-mode filters designed in 120 nm CMOS and 65 nm low-power CMOS. Their properties are described in detail.

Current-Mode Filters

Analog filters are required in many mixed-signal systems. They can be used for anti-aliasing purposes, before signals are sampled in an A/D converter or they can be used for reconstructing the signal after a D/A converter. Also at the output of a mixer a filter which suppresses out-of-band interferer signals is necessary. In general, when a filter is designed it is necessary to consider the whole system in which the filter is embedded. Important parameters for filters are in-band and also out-of-band distortions. A high in-band linear dynamic range avoids intermodulation between two in-band signals. Out-of-band distortions are also essential because they describe the immunity against some blockers or disturbances to other channels in a multi-band system. Other important parameters are the noise spectral density or the integrated noise. For some applications the out-of-band spectral noise density should be under a certain level, otherwise the noise would interfere to a neighboring channel. Sometimes, when the same filter is used in the I-path and in the Q-path of a receiver, the mismatch between these two filters should not be too high. G m -C filter topologies, a figure of merit, the state-of-art, the requirements for UWB and three implemented filters are described in this chapter.

Heimo Uhrmann

Papers

A 1GHz-GBW operational amplifier for DVB-H receivers in 65nm CMOS

A fully differential operational amplifier for a low-pass filter in a DVB-H receiver

A current-mode continuous-time filter for software defined radio solutions

Current-Mode Filters

G m -C Filters