Stmicroelectronics S.r.l.

Angelo Maria D'Arrigo

Filippo Marino

Francesco Pulvirenti

Salvatore Vincenzo Capici

Antonio Magazzu

Andrea Rapisarda

A clock frequency modulator for an oscillator having a digital circuit for the generation of a signal modulating the clock frequency, the digital circuit adapted to obtain, from the signal generated by the oscillator, a first pulse signal having a lower frequency than the clock frequency of the oscillator, a digital counter adapted to count the pulses of the first signal and to produce a digital signal and a digital-to-analog converter adapted to convert the digital signal in the signal for modulating the clock frequency of the oscillator.

Frequency modulator

A device suitable for charging a battery includes at least a first and a second transistor. The transistors are connected to an input voltage and have output terminals; the output terminal of the first transistor is connected to the battery. The device comprises a circuit for driving the transistors and the drive circuit comprises a regulator suitable for regulating the current in the battery during the charging phase of the battery. The regulator is suitable for keeping the voltage on the output terminals of the transistors the same during the charging phase of the battery.

Battery charging device with voltage-balanced transistors

A frequency translator is usable in a switching DC-DC converter of the type operating as a voltage regulator and as a battery charger. The frequency translator receives at inputs a division voltage (VFB) proportional to a present value of the output voltage (VOUT) of the DC-DC converter, a reference voltage (VREF) correlated to a nominal value of the output voltage (VOUT), and a limiting signal (VL) indicative of a normal operation or of current limitation operation of the DC-DC converter, and supplies at an output a bias current (IBIAS) which is supplied to an input of an oscillator supplying at an output a comparison signal (VC) presenting a periodic pattern with a frequency which is correlated to the bias current (IBIAS). In particular, the frequency translator operates in a way such as to regulate a frequency translation of the comparison signal (VC) as a function of the difference between the division voltage (VFB) and the reference voltage (VREF) only when the DC-DC converter is operating in the current limitation condition.

Frequency translator usable in a switching DC-DC converter of the type operating as a voltage regulator and as a battery charger, and method of frequency translation therefor

An electronic device smoothes a charge current peak in RLC output stages of switching step-up regulators, which stages include an input terminal and an output terminal with an inductance and a parasitic resistance in series therebetween, the latter corresponding to the series parasitic resistance of the inductance, and a capacitor connected between the output terminal and a ground. The device comprises a parallel of a resistor and a controlled switch connected between the inductance and the output terminal of the stage upstream of the capacitor. Advantageously, the switch would only be open during the charge transient of the capacitor.

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Catania, Italy

Angelo Maria D'Arrigo