Micrel, Incorporated

Raymond David Zinn

Charles Vinn

Matthew Weng

Michael Joseph Mottola

Lawrence R Sample

Andrew Cowell

A voltage regulation system is provided including detecting a feedback voltage less than a reference voltage; asserting a current source gate output by the feedback voltage less than the reference voltage; activating a gated current source by the current source gate output; and waiting a delay interval before negating the current source gate output for turning off the gated current source.

Voltage regulation system

A single chip hybrid regulator is disclosed having a first stage being a switching regulator and a second stage being a linear regulator. The switching regulator uses a filter circuit including an inductor and a capacitor. To make the hybrid regulator very small, the inductor value is selected so that the inductor saturates at a current level well below the maximum load current for the regulator. At low load currents, the small inductor does not saturate, and the regulated voltage applied to the input of the linear regulator presents only a small differential voltage across the series transistor of the linear regulator, resulting in very little power being wasted by the series transistor. At higher currents, the small inductor begins to saturate or fully saturates; however, the increased ripple is smoothed by the linear regulator. For applications, such as cell phones, where the regulator operates at low currents for the vast majority of the time, the overall efficiency of the regulator is extremely high and the regulated voltage is very smooth. As the inductor becomes highly saturated, or if the switching regulator cannot supply sufficient current, the switching regulator may be bypassed by the closing of a switch to continuously couple the power supply input voltage to the input of the linear regulator.

High efficiency linear regulator

A master transceiver automatically lowers its transmit power level at intervals until a slave transceiver no longer accurately receives the transmitted data. When the master detects an inaccurate transfer of data, the master incrementally increases the transmit power level until it is determined that there has been an accurate transfer of data. At that time, the master transmits an acknowledge signal to the slave. Since the automatic power adjust routine is performed using the transmitted data from the master and the error control information transmitted by the slave, there is little or no overhead used by the power adjust routine. Simple control circuitry can be used to carry out the functions.

Transmitter power level optimization and error correction technique

A PFM-type voltage regulator circuit converts an unregulated input voltage into a regulated output voltage using a first transistor controlled by a pulse control circuit and a second transistor controlled by a linear regulator circuit. The linear regulator circuit controls the second transistor when the regulated output voltage falls to a predetermined minimum target voltage level, thereby maintaining the regulated output voltage at the minimum target voltage level. The pulse control circuit detects the current passing through the second transistor, and in response generates a pulse signal having a predetermined duration that fully turns on the first transistor. The voltage through the first transistor is converted to an increasing inductor current that refreshes the regulated output voltage to a maximum target voltage level. When the pulse signal ends, the regulated output voltage again begins to fall toward the predetermined minimum target voltage level, and the cycle is repeated.

Pulse frequency modulated voltage regulator with linear regulator control

The present invention provides an apparatus and method for encoding and/or decoding signals. The encoding apparatus includes a variable impedance being coupled with an encoder. The variable impedance establishes a select voltage at the encoder. The encoder is further coupled with an input signal, wherein the encoder generates a modulated output as dictated by the select voltage. The decoding apparatus includes an integrator, a comparator and at least a first variable impedance. The integrator couples with the comparator, and is configured to receive an encoded signal and to generate an average DC voltage, such that the comparator receives the average DC voltage. The first variable impedance coupled with the comparator, and dictates a first limit such that the comparator receives the first limit. The comparator is configured to generate a decoded signal if the average DC voltage is at least equal to the first limit.

Apparatus and method for encoding signals

A voltage regulator is disclosed having a PWM portion and an LDO portion on a single chip. The PWM portion switches a large MOS transistor (or synchronous MOS transistors) at a high frequency to supply medium and high currents (e.g., 600 mA) to a load. During a standby mode, the regulator switches to an LDO mode and disables the PWM portion. The LDO mode controls a very small MOS series transistor to supply the standby mode current. Since the gate of the series MOS transistor is small, only a small variation in gate charge is needed to adequately control the conductance of the series transistor during the standby mode. Therefore, much less control current is used by the LDO than if the LDO used a series transistor of the same size as the switching transistor.

PWM buck regulator with LDO standby mode

The present invention provides an apparatus and method for optimizing the efficiency of a switching converter for converting a first voltage to a second voltage. The apparatus includes a regulator, a DC-to-DC converter and a controller. The controller couples with both the regulator and DC-to-DC converter, and the controller is configured to activate and deactivate the regulator and the DC-to-DC converter depending on an output demand. In one embodiment, the controller is configured to activate the regulator and deactivate the DC-to-DC converter when the output demand transitions from a first demand level to a second demand level. The controller is further configured to activate the DC-to-DC converter and to deactivate the regulator when the output demand transitions from the second demand level to the first demand level. The apparatus is configured to monitor demand, and to activate the DC-to-DC converter when demand is in a first state or activate the regulator when demand is in a second state.

Apparatus for converting voltage with regulator

In accordance with the present invention, trim pads used in trimming on-chip resistive elements are formed in the scribe channels interposed between respective dice on a wafer. Metal traces connect the trim pads to their associated resistive elements formed on the dice. Thus, each trim pad formed within the scribe channels results in a corresponding increase in the usable silicon surface area of the dice, thereby saving valuable silicon real estate.

Growing community of inventors

Atherton, CA, United States of America

Raymond David Zinn