ASICs circuits

Many of these steps include CVD, and CVD is now a major process in the fabrication of monolithic integrated circuits (IC), custom and semi-custom ASIC s, active discrete devices, transistors, diodes, passive devices and networks, hybrid IC s, opto-elec-tronic devices, energy-conversion devices, and microwave devices. 

Most microhotplate-based chemical sensors have been realized as multi-chip solutions with separate transducer and electronics chips. One example includes a gas sensor based on a thin metal film [16]. Another example is a hybrid sensor system comprising a tin-oxide-coated microhotplate, an alcohol sensor, a humidity sensor and a corresponding ASIC chip (Application Specific Integrated Circuit) [17]. More recent developments include an interface-circuit chip for metal oxide gas sensors and the conccept for an on-chip driving circuitry architecture of a gas sensor array [18,19]. 

Reactor 8 [R 8] Electrical Integrated Circuit Interconnect (ASIC) - Chip-to-world... 

The sensors of the electronic nose are assembled in an array. The array is normally a small electronic unit that integrates the different sensors into a practical circuit card or another appropriate system that is easy to insert into the electronic nose instrument. If the array is to be used in a flow injection setup the unit also comprises a flow cell compartment with minimal volume. The system depicted in Fig. 2 shows how MOS and MOSFET arrays are integrated in a flow injection system [11]. Larger arrays can be integrated into silicon chips, as described for CP sensors where, for example an ASIC chip with 32 sensors has been fabricated with BiCMOS technology and having an area of 7 x 7 mm [18]. If the array is be inserted in the headspace volume of a bioreactor, the technical solution is a remote array probe that can be placed in a gas sample container [19]. 

For this reason the ASIC concept is based on the modulation of the pressure measurement signal to a carrier frequency fm of approximately 5 kHz by square wave voltage supply of the gauge (H-bridge circuit). The signal is preamplified and then converted into a single-bit data stream with a data rate of fAZ=25G frn (about 1.28 Mbps) by a second-order AS modulator. The analog front-end (preamp and AS) is produced in fully differential SC circuitry. 

Because the 02 signal is derived from the interaction of pumping and Nernst cells, this sensor requires a special electronic controller circuit. This ASIC (application-specific integrated circuit) includes the basic pumping current control, internal resistance measurement, and extended hardware diagnostics for the sensor. 

Availability of multi-amplifier Application Specific Integrated Circuits (ASICs) with low powers of -1 mW per channel. 

Electronic circuits must be protected from the harsh environment of the human body. The packaging of implantable electronics uses various materials, including polymers, metals, and ceramics. The encapsulation method depends somewhat on the electronic circuit technology. Older devices may still use discrete components in a classical form, such as leaded transistors and resistors. The newer designs, depending on the sophistication of the implanted device, may employ application-specific integrated circuits (ASICs) and thick film hybrid circuitry for their implementation. Such circuits place considerable requirements for hermeticity and protection on the implanted circuit packaging. 

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