Dialog Semiconductor Gmbh

Andreas Sibrai

Josef Niederl

Nikolay Tchamov

Kurt Fritzwenwallner

Walter Meusburger

A voltage controlled variable capacitor, formed of a larger number of fixed capacitor segments and a corresponding number of switching elements, uses translinear amplifiers to control each switching element. Each translinear amplifier linearly switches from the fully off to the fully on state; a minimum number of switching stages (ideally only one) is in the mode-of-change at any one time with a minimum overlap. The arrangement achieves a nearly linear change of capacitance at linear tuning voltage change, while resulting in high Q-factor due to the low RDSon and high RDSoff of the fully switched stages. The invention eliminates temperature and voltage dependencies of other solutions like varactor diodes.

High Q linear controlled variable capacitor using translinear amplifier

A voltage controlled variable capacitor, formed of a larger number of fixed capacitor segments and a corresponding number of switching elements, linearly switches on each switching element, one after the other. Several techniques are disclosed to have only a minimum number of switching stages being in the active mode-of-change at any one time with a minimum overlap. The arrangement achieves a nearly linear change of capacitance versus tuning voltage change, while resulting in high Q-factor due to the low RDSon and high RDSoff of the fully switched stages.

High Q linear controlled variable capacitor

A circuit and a method are given, to realize a very efficient driver device for igniters or squibs as used e.g. in airbag applications. Special attention has been turned to include secure and always reliable operating features into the device and at the same time to reach for a low-cost implementation with modern integrated circuit technologies. Controlled firing operation and sophisticated diagnostic mechanisms are realized. These design features have been acquired by use of current mirror circuit principles for the switching devices where appropriate and with special regard to production cost. Current trimming and limitation to secure values are part of the solution.

Low cost squib driver for airbag application

A circuit and a method are given, to realize a very efficient driver device for igniters or squibs as used e.g. in airbag applications. Special attention has been turned to include secure and always reliable operating features into the device and at the same time to reach for a low-cost implementation with modern integrated circuit technologies. Controlled firing operation and sophisticated diagnostic mechanisms are realized. These design features have to a great extent been acquired by consequently using current mirror circuit principles. Current trimming and limitation to secure values are part of the solution.

Squib driver for airbag application

Methods to achieve low power consumption, high output amplitude and an improved high frequency stability, and high speed for voltage-controlled oscillators are disclosed These methods includes to provide a current mirror, a power supply voltage Vdd, two single-ended outputs, a lower layer of gain providing structure comprising cross-coupled transistors, an upper layer of gain providing structure, a control voltage, a pair of capacitors to block a DC-connection to the gates of said cross-coupled transistors, a pair of resistors, and an LC-tank. Important steps of these methods include to set the time instances when said transistors of lower layer of gain providing structure open and close, to shut-down the transistors of lower layer of gain providing structure as soon as the energy required to keep the oscillations in said LC-tank is secured, to add additional gain in the amplification loop; and to pump-out charges of the channels of said transistors of said lower layer gain providing structure.

Enhanced architectures of voltage-controlled oscillators with single inductor (VCO-1L)

A method and circuits of a high isolation and high-speed buffer amplifier capable to handle frequencies in the GHz range have been achieved. The output to input isolation is primary dependent on the gate-source capacitance of the active buffer transistor. Having two or more in series and by reducing the impedance between them a high isolation can be achieved. The input signals are split in several signal paths and are amplified in the push-pull mode using source follower amplifiers. Then the amplified signals are being combined again. The amplified output current is mirrored applying a multiplication factor. Said method and technology can be used for buffer amplifiers having differential input and differential output or having single input and single output or having differential input and single output. A high reversed biased (output to input) isolation and a reduced quiescent current have been achieved.

High isolation/high speed buffer amplifier

In a translinear amplifier, where the output voltage difference is kept at the same relative difference as the input voltage difference and which is normally formed by two current balancing circuits and some form of an amplifier stage, said amplifier stage is drastically simplified and even replaced by a simple diode. Two additional functions sharply limit the analog operating region: an added current limiting transistor on one side and the purpose use of the voltage limited by the power supply on the other side. One key objective is linearly switching on or off a transistor, and getting sharp maxima and minima of its RDSon at the extreme ends.

Translinear amplifier

Five circuit topologies of Voltage-Controlled Oscillators with Single Inductor (VCO-L) are proposed. They offer lower power consumption, higher output amplitude, broader tuning range, cleaner s-rum and higher frequency stability seen as lower phase-noise. Most of the achievements are based on the development of active pull-down control circuitries of the timing and active charge dissipation in the transistors. The applications of the present invention are of critical importance for wireless communication systems not allowing any limitations in the frequency range. Among them are base stations and mobile terminals mobile phones, GSM, PCS/DCS, W-CDMA etc., as well BlueTooth, Wireless LAN, Automotive and ISM band etc. The advanced performance of the circuits is based on important architectural specifics and proven by simulation on advanced CMOS process. The architectures are not limited to use on CMOS; they can be efficiently used in any semiconductor process where complimentary polarity transistors are available, for example BiCMOS, SiGe/BiCMOS, GaAs etc.

A highly stable single chip resonator controlled oscillator with automatic amplitude control and biasing is designed for manufacture with monolithic integrated circuit technologies. Analog and digital output buffers with elaborate control for power saving purposes and sophisticated start-up and power-up circuits ensure, that a crystal controlled oscillation is safely induced at start-up and that the amplitude of oscillation is continuously controlled during operation to reach low phase noise and reduce power consumption of the circuit.

High quality parallel resonance oscillator

A highly stable single chip resonator controlled oscillator with automatic gain control designed for manufacture in monolithic integrated circuit technologies. An automatic gain controller monitors the output of a crystal controlled oscillator amplifier and produces a feedback signal to ensure oscillation is induced at startup and that the amplitude of oscillation is continuously controlled during operation to reach low phase noise and reduce power consumption of the circuit.

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Krottendorf, Austria

Andreas Sibrai