Abstract:
A switching power supply (40) for supplying a load requiring a controlled current includes a PFC pre-regulator (45) for receiving an input voltage (V AC ) and providing an output voltage (V IN ), and a DC-DC switching converter (46) for receiving at input the voltage (V IN ) output by the pre-regulator (45) and for providing at output a supply voltage of said load. The switching DC-DC converter (40) operates at a fixed and constant operating frequency, is a resonant converter and includes an LLC resonant circuit.
Abstract:
A control device for a resonant converter is described; the converter comprises a switching circuit (Q1-Q2) adapted to drive a resonant load (Cr, 20). The resonant load comprises at least one transformer (20) with at least a primary winding (L1) and at least a secondary winding (L2) and the converter is adapted to convert an input signal (Vin) into an output signal (Vout); the switching circuit comprises at least a half bridge of first (Q1) and second (Q2) switches and the central point (HB) of said half bridge is connected to said resonant load (Cr, 20). The control device comprises first means (116) adapted to rectify a signal (Vs) representative of the current (Ir) circulating in the primary winding, second means (111) adapted to integrate at least said rectified signal (Vs') and being adapted to generate at least a control signal (HSGD, LSGD) of said switching circuit according to the integrated signal (Vint), third means (FF, CO1, 118, CO2) adapted to send a reset command to said second means so as to inhibit the operation over a time period (Tres) between the instant when said integrated signal reaches or overcomes a first signal (Vc, V2) and the instant of the next zero crossing of the signal (Vs) representative of the current (Ir) circulating in the primary winding. ( Figure 3 )
Abstract:
An integrated power MOSFET device formed by a substrate (19, 65); an epitaxial layer (13; 68; 80, 81) of N type ; a sinker region (17b) of P type, extending through the epitaxial layer from the top surface and in electrical contact with the substrate; a body region (22), of P type, extending within the sinker region from the top surface; a source region (25), of N type, extending within the body region from the top surface, the source region delimiting a channel region (22a); a gate region (19); a source contact (30), electrically connected to the body region and to the source region; a drain contact (31), electrically connected to the epitaxial layer (13; 81); and a source metallization region (104), extending over the rear surface and electrically connected to the substrate and to the sinker region.
Abstract:
There is described a control device (100) of a switching circuit (200) for a resonant converter (1) having a direct current at the output (Iout); the switching circuit (200) comprises at least one half bridge of at least first (Q1) and second (Q2) transistors connected between an input voltage (Vin) and a reference voltage (GND). The half bridge is adapted to generate a periodic square wave voltage to drive the resonant circuit (300) of said resonant converter; the periodic square wave voltage ranges from a high voltage corresponding to the input voltage, to a low voltage corresponding to the reference voltage. The control device (100) is adapted to control said half bridge according to the time period of charging or discharging a capacitor (Ct) and comprises circuit means (101) adapted to synchronize the starting time instant (Tstart) of the time period of discharging or charging the capacitor (Ct) crossing the zero value of a signal (Vs) indicating the current (Is) flowing in the resonant circuit (300) and further means (102, 103) adapted to control the switching off of the first (Q1) or second (Q2) transistor at the end of the time period of discharging or charging the capacitor (Ct).
Abstract:
There is described a detecting device for the midpoint voltage (Va) of a half bridge circuit of transistors (M1, M2) comprising first (M1) and second (M2) transistors; the half bridge is connected between a voltage supply (Vcc) and a reference voltage (GND) and it is adapted to drive a load (LOAD). The first and second transistors are driven so that said midpoint voltage (Va) undergoes transitions from a low voltage value (LW) to a high voltage value (HW) and vice versa; the circuit comprises a bootstrap capacitor (Cboot) having one terminal connected to the midpoint node and the other terminal connected to a supply circuit (15) of said bootstrap capacitor. The detecting device comprises a further capacitor (Cgd) adapted to be connected between said other terminal of the bootstrap capacitor and circuit means (12, Cpump) adapted to form a low impedance node for the current signal (Isink, Isource) circulating in said further capacitor (Cgd) during the transitions from the low value to the high value and from the high value to the low value of the midpoint voltage (Va). The device comprises detecting means (10) adapted to detect said current signal circulating in said further capacitor and adapted to output at least a first signal (HL_comm, LH_comm) indicating the transitions from the low value to the high value or from the high value to the low value of the midpoint voltage according to said current signal.
Abstract:
A control device for a resonant converter is described; the converter comprises a switching circuit (Q1-Q2) adapted to drive a resonant load (Cr, 20), said resonant load comprising at least one transformer (20) with at least a primary winding (L1) and at least a secondary winding (L2). The converter is adapted to convert an input signal (Vin) into an output signal (Vout) and the switching circuit comprises at least a half bridge of first (Q1) and second (Q2) switches; the central point (HB) of said half bridge is connected to the resonant load. The control device comprises first means (110) adapted to integrate at least one signal (Vs) representative of a half wave of the current (Ir) circulating in the primary winding (L1); said first means are adapted to generate at least a control signal (HSGD, LSGD) of the switching circuit depending on the integrated signal (Vint). The control device comprises second means (120) adapted to set the equality of the switching-on time period (Ton1, Ton2) of said first and second switches. ( Figure 3 )
Abstract:
Control device for a rectifier of a switching converter; the converter is powered by an input voltage and is suitable for providing an output current (Iout). The rectifier (T1, T2) is suitable for rectifying said output current of the converter and comprises at least one transistor (T1); the control device (100, 200, 300) is suitable for driving said at least one transistor. The control device comprises first means (100) suitable for identifying the start and the end of every converter switching half-cycle and measuring the duration thereof, second means (200) suitable for generating a signal (EN-SR) for turning on said transistor after a given number (n) of measured converter switching half-cycles and when the output current (Iout) of the converter becomes greater than a reference current (Iref). ( Fig. 3 )
Abstract:
A solution is proposed for controlling a resonant switching system (110), which includes a first switch (Ml) and a second switch (Mh) in a half-bridge configuration for driving a resonant load (L,105,C1). A corresponding control system (115) includes command means (405-410,4151,415h) for switching on and switching off the switches alternatively according to a working frequency of the switching system. In a solution according to an embodiment of the invention, the control system includes detection means (420-430) for detecting a zeroing (tz) of a working current (I(L)) being supplied by the switching system to the resonant load in a temporal observation window (Tm); the observation window follows each switching off of at least one of the switches (Ml), and has a length equal to a fraction of a working period of the switching system. Correction means (435;535) are then provided for modifying the working frequency in response to each detection of the zeroing in the observation window.