Renesas Electronics America Inc.

Intersil Americas Inc.

Narendra Kayathi

Travis Guthrie

James R Toker

Brannon Craig Harris

Robert Thomas Grisamore

Aaron Shreeve

Kiran Gonsalves

Timothy William Nutt

Methods and systems for operating a voltage regulator are described. An apparatus may receive a feedback signal from a power stage. The feedback signal may be one of a sensed signal measured from an output of the power stage and a calibration signal representing a fixed voltage. The apparatus may convert the feedback signal into a correction signal. The apparatus may further adjust a synthetic current using the correction signal, the synthetic current being associated with the power stage.

System level offset calibration of multiphase voltage regulator

According to certain aspects, a predictive tracking scheme is provided for sampling inductor currents in a digital PWM controller used for high-bandwidth voltage regulation. In one or more embodiments, the predicted current derived from the PWM waveform is fed forward to the current sense ADC in order to reduce the required conversion range. These and other embodiments only need to convert a few of the LSB of the ADC in order to correct the largest error expected in the synthesizer.

Method for sensing inductor current across range exceeding ADC dynamic range and PWM controller system including ADC therefor

In one or more embodiments, an efficient scheme is provided for sampling inductor currents in a digital multiphase PWM controller used for high-bandwidth voltage regulation. Some embodiments use the data from the PWM modulator along with weighted states based on the PWM waveform and past conversions in order to prioritize which current sense input should be sampled for each conversion. In these and other embodiments, a single ADC is used to sample inductor currents from two or more phases in a multiphase PWM controller, thereby providing power and area savings, for example.

Predictive sample queueing for time-shared ADC in a multiphase PWM controller

According to certain aspects, the present embodiments provide a solution for sampling and converting an analog signal at high frequencies but with low power consumption. In some embodiments, a low power, low resolution, AC coupled ADC is used to track the high frequency component of the analog input signal, in parallel with a high resolution ADC to sense the DC signal at a significantly lower sample rate. According to some aspects, the AC coupled ADC requires no reference or a low resolution reference. In these and other embodiments, a plurality of low resolution, low power ADCs having a high sampling rate may be time multiplexed together with a precision ADC at a low sampling rate.

Low power ADC sampling in a digital power controller

A current measurement circuit may include unbuffered inputs, and the current may be sampled directly from the input pins. The input current created from each sample may be cancelled by injecting opposite charge on the subsequent sample. This direct sampling from the pins increases the common mode input range of the sense path without having to build high linearity rail-to-rail input buffers, hence lowering cost and power consumption of the current measurement path. It also allows for high-impedance input sampling. The measurement circuit may include multiple sampling stages, with a first sampling stage implemented as a switched-capacitor based circuit. A compensator circuit coupled in a feedback loop from the output of the first sampling stage to the input pins may be operated to provide the equivalent charge back to the input pins every cycle to cancel the input current required to charge the sampling capacitors of the first sampling stage.

Input current compensation during current measurement

An adjustable current-synthesizer may generate synthesized current representative of an actual current, according to a model of a circuit that produces the actual current. The current synthesizer may under-sample a current sense signal derived from the actual current to obtain a few samples of the actual current, which are then used to adjust the synthesized current, thereby ensuring accuracy of the synthesized current. Sample values of the actual current are compared with corresponding generated values of the synthesized current to obtain offset values. In order to maintain monotonicity in the synthesizer results, the offset values are used to make adjustments to the slope of the synthesized current. The slope of the synthesized current may also be adjusted according to the slope of the actual current. Sub-Nyquist sampling of the actual current may be performed on the down-slope, with up-slope adjustments made based on the offset adjustment and down-slope adjustment.

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Austin, TX, United States of America

Narendra Kayathi