Stmicroelectronics S.r.l.

Ignazio Cala'

Santi Carlo Adamo

Fabrizio Librizzi

Sergio Franco Pioppo

Franco Lentini

Pietro Scalia

A circuit includes a set of LED driver devices and a controller including a set of nodes coupled to a first slave address pin and a second slave address pin in each LED driver devices in the set of LED driver devices. Each LED driver device includes a finite state machine (FSM) configured to generate LED drive PWM-modulated signal patterns, an oscillator configured to generate a clock signal for the FSM, a first signal path activatable between the first slave address pin and the FSM, and a second signal path activatable between the FSM and the second slave address pin.

LED driver circuit, corresponding device and method

A circuit includes: a plurality of memory locations configured to store pulse width modulation (PWM) signal generation data, the memory locations being arranged in N sets of memory locations, each including i channel memory locations, each channel memory location being configured to store a respective duty-cycle value for a respective one of N PWM modulation patterns; a selection circuit configured to selectively access a selected set of the sets of memory locations; a buffer circuit configured to store the PWM signal generation data from the channel memory locations of the selected set; and a finite state machine configured to receive PWM signal generation input data indicative of a plurality of PWM modulation patterns with a respective plurality of duty-cycle values, the finite state machine configured to activate the selection circuit to load the PWM signal generation data from the channel memory locations of the selected set to the buffer circuit.

Pulse width modulation pattern generator circuit, corresponding device and method

An electronic device includes a set of programming terminals for receiving corresponding programming signals, and assignment circuitry for assigning an address to the electronic device according to the programming signals. The assignment circuitry includes circuitry for providing a set of comparison signals, with at least part of the comparison signals that is variable during a non-zero comparison interval, and comparison circuitry for determining the address according to a comparison between the programming signals and the comparison signals during the comparison interval.

Electronic device with address programmable through reduced number of terminals

Presented is a circuit and method capable to digitally control and, in particular, to control the switching of one or two MOSFETs used as rectifiers in switched mode power supply isolated topologies. Basic circuit implementation of the presented technique is also introduced. A controller has a fixed frequency square wave signal main clock input, generically switching from a low to a high value in two different time intervals. The controller has one or two square wave outputs, swinging from low to high in phase or in opposite with respect to the clock signal. The digital control method is able to generate output signals timed to anticipate output transitions from high to low level with respect to the clock signal transitions. In the control scheme, one or two other secondary inputs set the amount of anticipation time of the respective transitions of the outputs. In isolated SMPS topologies with the PWM controller located on the primary side, the clock signal is derived from the secondary output of the isolation transformer, while the outputs are meant to drive one or two MOSFET gates. The method is able to provide the proper gate drive signals, solving all the known problems in controlling synchronous rectification.

Method and apparatus to digitally control turn-off time of synchronous rectifiers in isolated topologies for switched mode power supplies

A circuit and method are disclosed for controlling the slew rate of the output voltage of a driver in a push-pull configuration. The circuit includes a capacitive element and a current generator circuit for generating one or more currents. The circuit further includes a switching circuit for selectively charging and discharging the capacitive element in response to an input signal, wherein the voltage across the capacitive element is a voltage signal whose edge transitions have slopes which are controlled based upon the capacitance of the capacitive element and the current level of the one or more currents. The circuit further includes a conversion circuit for converting the voltage signal into one or more current signals, the one or more current signals being used to control a pull-up device and pull-down device of the driver so that the slopes of the edge transitions of the output voltage thereof is based upon the slopes of the edge transitions of the voltage signal appearing across the capacitive element.

Growing community of inventors

Syracuse, Italy

Ignazio Cala'