Dialog Semiconductor Gmbh

Lattice Semiconductor Corporation

Dialog Semiconductor B.v.

Ludmil Nikolov

Ambreesh Bhattad

Harald Weller

Carlos Calisto

Om P Agrawal

Shyam Chandra

Douglas Morse

Ji Zhao

Michael G France

Marinus Wilhelmus Kruiskamp

Hans W Klein

Frederic N F Deboes

Geoffrey R Richard

Circuits and methods providing a electronic power supply applicable to any dual supply rail systems, which require a smooth and uninterrupted output supply and a replica power path and autonomous mode of operation from the system power supply are disclosed. In a preferred embodiment of the invention the power supply is applied to a real time clock. An Innovative Replica Power Path concept and circuit implementation ensures the smooth and uninterrupted transfer of power from one input source to the other. The circuit features a Latched Supply Comparator that guarantees the commutation to the Replica Power Path only happens after the voltage is settled. Zero power consumption from the back-up energy source is achieved in the presence of an alternative higher voltage source. The generated RTC supply voltage does not suffer from abrupt changes when the voltage level of the main system power source (battery or charger) is connected or disconnected. The invention allows for maximum utilization of the energy left in the main battery, thus extending the life of the lower capacity backup battery/super-cap.

Dual input RTC supply generation with replica power path and autonomous mode of operation from the system supply

An apparatus and method for a system with improved power supply rejection ratio (PSRR) over a wide frequency range. The improved PSRR is achieved by negating the influence of the parasitic capacitance associated with the bias lines and the introduction of a regulated power supply with embodiments associated with providing a ripple free and regulated supply. With reduction of parasitic capacitance, and providing an ENABLE switch by a pre-regulated supply, the degradation of the PSRR is achieved. The embodiments include both n-channel and p-channel MOSFETs implementations, and a positive and negative regulated power supply voltage. With the combined influence of the utilization of the VREG supply, and the lowering of battery-to-bias line capacitance using design layout and improved floor planning an improved PSRR over a wide frequency distribution is achieved.

Apparatus and method for a voltage regulator with improved power supply reduction ratio (PSRR) with reduced parasitic capacitance on bias signal lines

Circuits and methods to improve dynamic load transient performance of circuits supplying high current and having parasitic resistances are disclosed. These circuits comprise e.g. LDOs, amplifiers or buffers. The circuits and methods are characterized by including parasitic resistances, caused by bond wires, metallization of pass devices, and substrate routings, in a loop for fast transient response. Furthermore the circuits comprise a stabilization circuit within said loop and a separate pad for said loop.

Load transient, reduced bond wires for circuits supplying large currents

Circuits and methods to maintain a resistive voltage divider ratio during start-up of an electronic circuit comprising a feed-forward capacitor across a feedback resistor using a dynamic start-up circuit are disclosed as e.g. a LDO or an amplifier. In a preferred embodiment of the disclosure is applied to an LDO. Modification of the resistive voltage divider ratio caused by the feed-forward capacitor during start-up is prevented while the voltage level of a voltage access point of the voltage divider on the feed-forward capacitor is maintained. A start-up circuit comprises a start-up capacitor and a start-up comparator.

Maintaining the resistor divider ratio during start-up

Circuits and methods to achieve a clean start-up process and power saving of pulsed enabled electronic devices having an output capacitor and components requiring biasing during normal operating conditions are disclosed. These electronic devices could be e.g. LDOs, amplifiers or buffers. A set of switches are enabling bias currents from the output capacitor to internal nodes requiring biasing under normal operational conditions as e.g. output nodes of amplifying means.

Clean startup and power saving in pulsed enabling of LDO

A self-biased reference circuit device () includes a first cascode current mirror (), a second cascode current mirror (), and a startup circuit (). The first cascode current mirror () is capable to generate a first bias voltage () and a second bias voltage () in response to a first current and to generate a second current in response to the first and second bias voltages. The second cascode current mirror () is capable to generate a third bias voltage () in response to the second current, to generate a fourth bias voltage () in response to a third current, and to generate the first current in response to the third and fourth bias voltages. The startup circuit includes a first switch () and a second switch (). The first switch () is capable to connect the first bias voltage () and fourth bias voltage () during startup. The second switch () is capable to connect the third bias voltage () and an inner drain-source connection () in the output stage of the first cascode current mirror () during startup.

Startup circuit for low voltage cascode beta multiplier current generator

Circuits and methods for power efficient generation of supply voltages and currents in an integrated circuit by reducing the power consumption of all core analog circuit blocks by a pulsed operation mode are disclosed. In a preferred embodiment of the invention the invention has been applied to a power management chip. Pulsed Mode of Operation of ALL core analog blocks&#x2014;internal LDO/s, VREF an IBIAS generators, results in significantly reduced power consumption. New circuit realizations and control algorithms to improve the ON/OFF ratio of the Pulsed Mode Operation yield in better power efficiency. Innovative circuit implementation consisting of an additional Top Up Buffer Amplifier stage ensures a fast recharge of VREF output, thus allowing shorter ON times and respectively even better power efficiency. Bypassing a low bandwidth and slow to start LDO with a fast Bypass Comparator supplies a LDO rail in Pulsed Mode of operation. A Dynamic Control of the Commutating Components ensures least disturbance of the voltage potentials, thus allowing shorter ON times and respectively better power efficiency. The invention can also be applied to reference voltage and to bias current generator circuits.

Power efficient generation of band gap referenced supply rail, voltage and current references, and method for dynamic control

In one embodiment, a clock distribution chip includes a clock input adapted to receive an input clock signal, clock dividers each adapted to receive a clock signal based on the first input clock signal and to generate a divided clock signal, and programmable clock outputs adapted to provide output clock signals. The clock outputs are configurable to support a number of signaling standards. A programmable switch fabric is coupled between the clock dividers and the clock outputs and is configurable to provide the divided clock signals to the clock outputs.

Clock distribution chip

In one embodiment, a clock distribution chip includes a first clock input adapted to receive a first single-ended input clock signal, a second clock input adapted to receive a second single-ended input clock signal, and input buffer circuitry coupled to the first and second clock inputs. The input buffer circuitry is adapted to select an input clock signal among the first single-ended input clock signal, the second single-ended input clock signal, and a differential input clock signal derived from the first and second single-ended input clock signals. A phase-locked loop (PLL) is adapted to receive an input clock signal selected by the input buffer circuitry and to generate a PLL clock signal based on the selected input clock signal. A clock output provides an output clock signal based on the PLL clock signal.

In one embodiment, a method is provided for measuring a dynamic phase offset between a PLL's input clock and the PLL's feedback input clock, wherein the input clock is spread spectrum modulated in a spread spectrum mode and is not modulated in a static mode. The method includes: in the spread spectrum mode, measuring phase jitter between the input clock and the feedback input clock to form a spread spectrum phase jitter measurement; in the static mode, measuring phase jitter between the input clock and the feedback input clock to form a static phase jitter measurement; and comparing the spread spectrum phase jitter measurement to the static phase jitter measurement to determine the dynamic phase offset.

Dynamic phase offset measurement

In one embodiment of the invention, a clock distribution (CD) chip has one or more input pins, input buffer circuitry, clock generation and distribution circuitry, fanout circuitry, one or more output pins, a feedback pin, and feedback buffer circuitry. Based on single-ended or differential input clock signals applied to the input pins, the CD chip can be programmably configured to generate zero, one, or more zero-delay (ZD) output clock signals and zero, one, or more non-zero-delay (NZD) output clock signals for simultaneous presentation at the output pins.

Clock distribution chip for generating both zero-delay and non-zero-delay clock signals

Improved common mode feedback techniques are provided for charge pumps, phase-locked loops (PLLs), and other circuits. For example, in accordance with an embodiment of the present invention, a circuit includes a loop filter having first and second loop filter nodes. An amplifier is provided having first and second differential inputs respectively coupled to the first and second loop filter nodes. A first current source is coupled to the first loop filter node and a second current source is coupled to the second loop filter node. The first and second current sources continuously adjust a common mode voltage of the loop filter nodes.

Phase-locked loop systems and methods

In accordance with one or more embodiments of the present invention, a system includes a phase-locked loop circuit that receives a reference signal and a feedback signal and provides an output signal. A control circuit also receives the reference signal and the feedback signal and provides a correction current for the phase-locked loop circuit to reduce a phase error of the output signal.

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Chippenham, United Kingdom

Ludmil Nikolov