Alpha & Omega Semiconductor Patent Grants

Switching regulator implementing power recycling

Granted: January 16, 2024
Patent Number: 11876456
A controller for a switching regulator receiving an input voltage and generating a regulated output voltage includes a buck control circuit and a boost control circuit. The controller activates the buck control circuit to generate the regulated output voltage having a first voltage value less than the input voltage. The controller activates the boost control circuit to return charges stored on the output capacitor at the output node to the input node, thereby driving the regulated output…

Bottom source trench MOSFET with shield electrode

Granted: January 9, 2024
Patent Number: 11869967
An improved inverted field-effect-transistor semiconductor device and method of making thereof may comprise a source layer on a bottom and a drain disposed on a top of a semiconductor substrate and a vertical current conducting channel between the source layer and the drain controlled by a trench gate electrode disposed in a gate trench lined with an insulating material. A heavily doped drain region is disposed near the top of the substrate surrounding an upper portion of a shield trench…

High bandwidth constant on-time PWM control

Granted: January 2, 2024
Patent Number: 11863057
Apparatus and associated methods relate to dynamic bandwidth control of a variable frequency modulation circuit by selective contribution of a crossover frequency tuning engine (XFTE) in response to a transient in a switching frequency. In an illustrative example, the XFTE may generate a transient control signal (Ctrans) in response to a transient in a control output signal (Cout) indicative of switching frequency and received from a feedback control circuit. The XFTE may generate…

Circuit and method for controlling switching regulator with ultrasonic mode

Granted: December 19, 2023
Patent Number: 11848608
A control circuit for controlling a switching regulator includes a timer, a comparator, a driver circuit and a controller. The timer generates an input signal indicative of whether a predetermined amount of time has elapsed since an activation of a drive signal. The comparator is configured to compare a feedback voltage with a reference voltage to generate a comparison signal. The driver circuit is controlled by a control signal to generate the drive signal according to one of the input…

Port controller with real-time fault detection

Granted: November 7, 2023
Patent Number: 11809249
A port controller circuit is configured to control power transfer on a power path between a first terminal and a second terminal. The controller circuit includes first and second transistors connected in series between the first terminal and the second terminal, a control terminal of the first transistor receiving a first gate voltage and a control terminal of the second transistor receiving a second gate voltage. A first gate voltage control circuit generates the first gate voltage…

Semiconductor package having smart power stage and e-fuse solution

Granted: October 24, 2023
Patent Number: 11798882
A semiconductor package comprises a lead frame, a low side metal-oxide-semiconductor field-effect transistor (MOSFET), an E-fuse MOSFET, a high side MOSFET, a metal connection, a gate driver, an E-fuse IC, and a molding encapsulation. A buck converter comprises a smart power stage (SPS) network and an E-fuse solution network. The SPS network comprises a high side switch, a low side switch, and a gate driver. A drain of the low side switch is coupled to a source of the high side switch…

Semiconductor package having thin substrate and method of making the same

Granted: October 10, 2023
Patent Number: 11784141
A semiconductor package comprises a semiconductor substrate, a first metal layer, an adhesive layer, a second metal layer, a rigid supporting layer, and a plurality of contact pads. A thickness of the semiconductor substrate is equal to or less than 50 microns. A thickness of the rigid supporting layer is larger than the thickness of the semiconductor substrate. A thickness of the second metal layer is larger than a thickness of the first metal layer. A method comprises the steps of…

SiC MOSFET with reduced channel length and high V

Granted: October 3, 2023
Patent Number: 11776994
A silicon carbide MOSFET device and method for making thereof are disclosed. The silicon carbide MOSFET device comprises a substrate heavily doped with a first conductivity type and an epitaxial layer lightly doped with the first conductivity type. A body region of a second conductivity type opposite the first is formed in epitaxial layer and an accumulation mode region of the first conductivity type is formed in the body region and an inversion mode region of the second conductivity…

Method and circuit for sensing MOSFET temperature for load switch application

Granted: October 3, 2023
Patent Number: 11774296
A method and device for temperature monitoring of a power transistor formed in a semiconductor die comprising are disclosed. A side of a temperature-sensing resistor disposed in the semiconductor die is coupled to a voltage input side of the power transistor. A controller coupled to a second side of the temperature-sensing resistor is configured to detect a voltage across the resistor and trigger a temperature related corrective action using the detected voltage.

Semiconductor package having a lead frame including die paddles and method of making the same

Granted: June 27, 2023
Patent Number: 11688671
A semiconductor package comprises a lead frame, a first field-effect transistor (FET), a second low side FET, a first high side FET, a second high side FET, a first metal clip, a second metal clip, and a molding encapsulation. The semiconductor package further comprises an optional integrated circuit (IC) controller or an optional inductor. A method for fabricating a semiconductor package. The method comprises the steps of providing a lead frame; attaching a first low side FET, a second…

Multi-phase switching regulator with variable gain phase current balancing using slope-compensated emulated phase current signals

Granted: June 20, 2023
Patent Number: 11682974
A multi-phase current mode hysteretic modulator implements phase current balancing among the multiple power stages using slope-compensated emulated phase current signals and individual phase control signal for each phase. In some embodiments, the slope-compensated emulated phase current signals of all the phases are averaged and compared to the slope-compensated emulated phase current signal of each phase to generate a phase current balance control signal for each phase. The phase…

Flyback converter for controlling on time variation

Granted: May 30, 2023
Patent Number: 11664734
A flyback converter to control conduction time in AC/DC conversion technology. The flyback converter includes a primary side and a secondary side. The primary side includes a main switch connecting a primary coil to the input of the flyback converter in series. The secondary side includes a secondary coil coupling with the output terminal of the flyback converter. When a switching frequency of the main switch is at a preset first on time in the range between the off frequency and the…

Low capacitance transient voltage suppressor including a punch-through silicon controlled rectifier as low-side steering diode

Granted: May 30, 2023
Patent Number: 11664368
A transient voltage suppressor (TVS) device uses a punch-through silicon controlled rectifier (SCR) structure for the low-side steering diode where the punch-through SCR structure realizes low capacitance at the protected node. In some embodiments, the punch-through silicon controlled rectifier of the low-side steering diode includes a first doped region formed in a first epitaxial layer, a first well formed spaced apart from the first doped region where the first well is not biased to…

Port controller power path short detection

Granted: May 9, 2023
Patent Number: 11646570
A system and method in an electronic system including multiple serial ports, each coupled to a port controller circuit. In one embodiment, the method includes providing a monitor terminal at each port controller circuit, each monitor terminal having a first resistance value; connecting together electrically at least two of the monitor terminals of the port controller circuits of the multiple serial ports; and sensing, at each port controller circuit, a first voltage at the monitor…

Port controller power path short detection

Granted: May 9, 2023
Patent Number: 11646570
A system and method in an electronic system including multiple serial ports, each coupled to a port controller circuit. In one embodiment, the method includes providing a monitor terminal at each port controller circuit, each monitor terminal having a first resistance value; connecting together electrically at least two of the monitor terminals of the port controller circuits of the multiple serial ports; and sensing, at each port controller circuit, a first voltage at the monitor…

Enhancement on-state power semiconductor device characteristics utilizing new cell geometries

Granted: March 28, 2023
Patent Number: 11616123
A semiconductor device and a method of making thereof are disclosed. The device includes a substrate heavily doped with a first conductivity type and an epitaxial layer lightly doped with the first conductivity type formed on the substrate. A buffer layer between the substrate and the epitaxial layer is doped with the first conductivity type at a doping level between that of the substrate and that of the epitaxial layer. A cell includes a body region doped with the second conductivity…

High bandwidth constant on-time PWM control

Granted: March 14, 2023
Patent Number: 11606018
Apparatus and associated methods relate to dynamic bandwidth control of a variable frequency modulation circuit by selective contribution of a crossover frequency tuning engine (XFTE) in response to a transient in a switching frequency. In an illustrative example, the XFTE may generate a transient control signal (Ctrans) in response to a transient in a control output signal trans, (Cout) indicative of switching frequency and received from a feedback control circuit. The XFTE may generate…

Sawtooh electric field drift region structure for planar and trench power semiconductor devices

Granted: February 28, 2023
Patent Number: 11594613
A lateral super junction JFET is formed from stacked alternating P type and N type semiconductor layers over a P-epi layer supported on an N+ substrate. An N+ drain column extends down through the super junction structure and the P-epi to connect to the N+ substrate to make the device a bottom drain device. N+ source column and P+ gate column extend through the super junction but stop at the P-epi layer. A gate-drain avalanche clamp diode is formed from the bottom the P+ gate column…

Semiconductor package having wettable lead flank and method of making the same

Granted: February 14, 2023
Patent Number: 11581195
A semiconductor package comprises a lead frame, a chip, and a molding encapsulation. The lead frame comprises one or more die paddles, a first plurality of leads, and a second plurality of leads. A respective end surface of each lead of the first plurality of leads and the second plurality of leads is plated with a metal. A first respective window on a first side of each lead of the first plurality of leads and the second plurality of leads is not plated with the metal. A second…

Phase redundant power supply with oring FET current sensing

Granted: February 7, 2023
Patent Number: 11575304
A power stage in a multi-phase switching power supply incorporates a current sense circuit coupled to the output voltage disconnect transistor to conduct a portion of an inductor current flowing in the output inductor of the power stage. The current sense circuit is controlled by the same control signal controlling the output voltage disconnect transistor. The portion of the inductor current being conducted by the current sense circuit includes an upslope current and a downslope current…