Slew rate sensing and control of a high-voltage output driver for a variable voltage range and variable output load
AssigneeDialog Semiconductor GmbH
InventorRainer Krenzke
Life of this patent
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Abstract
A circuit and method are given, to realize a high voltage output driver within a closed regulator loop with slew rate control, insensitive against supply voltage variations. The high-voltage front-end, essentially a slope detector, is implemented as a combination of a voltage-current with a current-voltage transformer circuit, where only very few parts are working in the high voltage domain. Using the intrinsic advantages of that solution the circuit of the invention is manufactured with standard CMOS technology and only two discrete or integrated extended drain MOS components at low cost.
Claims31
A method for realizing a stable high-voltage front-end for an output driver circuit, insensitive against supply voltage variations, comprising:
- providing a slope transformer circuit, a differentiator with clock, a regulator with clocked comparator and digital regulator part, and the output driver circuit driving an external load;
- transforming a static high supply voltage level into a static current;
- transforming a high-voltage input signal into a proportional current signal;
- combining said static current and proportional current signal into a resulting current input signal;
- mirroring said resulting current input signal into a proportional current output signal;
- generating a low voltage output signal representing said current output signal;
- performing differential transactions upon said low voltage output signal, in relation to given time steps from a clock generator;
- converting a low voltage differentiated output signal into a digital bit signal by a comparator using a given time step related reference;
- feeding said bit signal into a digital regulator part for further processing generate an digital output signal;
- convert said digital output signal into an analog signal as input to the output driver circuit;
- closing a regulator loop with an output signal from the output driver by feeding it back into a high voltage input signal;
- and
- driving a load with a high voltage output from the output driver.
A circuit, capable of driving higher loads for higher voltages and higher currents with slew rate controlled output signals, comprising:
- means for transforming a static high voltage supply level into a static current;
- means for transforming a dynamic high voltage input signal into a proportional current signal;
- means for combining said static current and said proportional current signal into a resulting current input signal;
- means for mirroring said resulting current input signal into a current output signal;
- means for generating a low voltage output signal representing said current output signal;
- performing differential transactions upon said low voltage output is signal, in relation to given time steps from a clock generator,
- converting a low voltage differentiated output signal into a digital bit signal by a comparator using a given time step related reference;
- feeding said bit signal into a digital regulator part for further processing and generate a digital output signal;
- convert said digital output signal into an analogue signal as input to an output driver circuit;
- means for driving an external load with a high voltage output from said output driver.
Dependencies are inferred from the claim text.