Fabio Cagnetti

A multi-channel power amplifier for driving a plurality of loads, each associated with a respective channel, each channel comprising a pair of operational amplifiers, first and second, one operational amplifier of each channel being connectable by configuring switches either in a bridge configuration with the other operational amplifier or in single-ended configuration to a constant reference voltage output by a dedicated voltage buffer of the multi-channel amplifier for driving the respective… Visualizza altro

A multi-channel power amplifier for driving a plurality of loads, each associated with a respective channel, each channel comprising a pair of operational amplifiers, first and second, one operational amplifier of each channel being connectable by configuring switches either in a bridge configuration with the other operational amplifier or in single-ended configuration to a constant reference voltage output by a dedicated voltage buffer of the multi-channel amplifier for driving the respective load of the channel, comprises a window comparator for monitoring the level of the input signal of the channel and producing a logic control signal for the configuring switches.
Each channel has a dedicated window comparator monitoring the level of the input signal of the channel that generates a logic signal for positioning the switches that configure the output power structure of the channel in single-ended or bridge configuration. Moreover, instead of configuring one of the operational amplifiers to function as a reference voltage buffer when switching to a single-ended configuration, a distinct voltage reference buffer is employed, to which any single-ended channel of the multi-channel amplifier is connected. Meno dettagli

A thermal protection device is for an integrated power MOSFET transistor including an interdigitated array of source regions and drain regions defined in a well region of the monocrystalline silicon substrate, and gate structures overhanging channel regions defined between adjacent source and drain regions. The thermal protection device may include a temperature sensor and a comparator for generating an over temperature flag signal usable for turning off the overheated power transistor. The… Visualizza altro

A thermal protection device is for an integrated power MOSFET transistor including an interdigitated array of source regions and drain regions defined in a well region of the monocrystalline silicon substrate, and gate structures overhanging channel regions defined between adjacent source and drain regions. The thermal protection device may include a temperature sensor and a comparator for generating an over temperature flag signal usable for turning off the overheated power transistor. The thermal protection device may sense, in a very accurate manner, the temperature of the power MOS and may include a circuit for forcing a fixed current through a small number of source regions of the interdigitated array separately connected from the other source regions electrically connected in common of the power transistor; and a comparator, integrated on the substrate outside the well region, comparing the source voltage present on the small number of separately connected source regions with a threshold voltage for producing on an output the over temperature flag signal. Meno dettagli

In a multi-channel amplifier switching from a single-ended to a bridge configuration, one of the two operational amplifiers of the output bridge structure of each channel is kept at the design reference voltage (typically to half the supply voltage) for as long as the other operational amplifier of the output bridge structure does not begin to saturate and by connecting in common the gate nodes of the P-type MOS transistors and the gate nodes of the N-type MOS transistors of the output half… Visualizza altro

In a multi-channel amplifier switching from a single-ended to a bridge configuration, one of the two operational amplifiers of the output bridge structure of each channel is kept at the design reference voltage (typically to half the supply voltage) for as long as the other operational amplifier of the output bridge structure does not begin to saturate and by connecting in common the gate nodes of the P-type MOS transistors and the gate nodes of the N-type MOS transistors of the output half bridge stages of all the operational amplifiers of the output bridge pairs of all the channels that are eventually configured to function as voltage reference buffer, when configuring the multi channel amplifier to function in a single-ended configuration Meno dettagli

A multi-channel power amplifier for driving a plurality of loads, each associated to a respective channel, each channel comprising a pair of operational amplifiers, first and second, one operational amplifier of each channel being connectable through switches either in a bridge configuration with the other operational amplifier or in single-ended configuration to a constant reference voltage for driving the load of the respective channel, the amplifier comprises circuit means for comparing the… Visualizza altro

A multi-channel power amplifier for driving a plurality of loads, each associated to a respective channel, each channel comprising a pair of operational amplifiers, first and second, one operational amplifier of each channel being connectable through switches either in a bridge configuration with the other operational amplifier or in single-ended configuration to a constant reference voltage for driving the load of the respective channel, the amplifier comprises circuit means for comparing the signal level of the channels with at least a threshold and outputting a logic control signal for the switches. A relative method of controlling a power amplifier that allows a sensible reduction of distortion at the price of a negligible increase of dissipated power is disclosed. Meno dettagli