High bandwidth, rail-to-rail differential amplifier with output stage amplifier
Granted: August 16, 2011
Patent Number:
7999618
An error amplifier expected to exhibit rail-to-rail operation, high bandwidth, and high slew rate, is described, the error amplifier comprising a first stage to receive an input differential voltage and to provide transconductance gain, an intermediate stage to provide current gain, and an output stage to drive a load.
Trench-gate MOSFET with capacitively depleted drift region
Granted: July 12, 2011
Patent Number:
7977193
A trench-gate metal oxide semiconductor field-effect transistor includes a field plate that extends into a drift region of the transistor. The field plate is configured to deplete the drift region when the transistor is in the OFF-state. The field plate is formed in a field plate trench. The field plate trench may be formed using a self-aligned etch process. The conductive material of the field plate and gate of the transistor may be deposited in the same deposition process step. The…
Trench-gate MOSFET with capacitively depleted drift region
Granted: July 12, 2011
Patent Number:
7977742
A trench-gate metal oxide semiconductor field-effect transistor (MOSFET) includes a field plate that extends into a drift region of the MOSFET. The field plate, which is electrically coupled to a source region, is configured to deplete the drift region when the MOSFET is in the OFF-state. The field plate extends from a top surface of a device substrate, which comprises an epitaxial layer formed on a silicon substrate. The field plate has a depth greater than 50% of a thickness of the…
Chip scale package for power devices and method for making the same
Granted: May 17, 2011
Patent Number:
7944048
A chip scale package is disclosed that includes a semiconductor die further comprising an array of power buses electrically coupled to a high power integrated circuit, and a plurality of Under Bump Metallization (UBM) multi-layer power buses disposed parallel to one another and spanning substantially across the entire length of the semiconductor die. The plurality of multi-layer UBM power buses, electrically coupled to the array of power buses, further includes a thick metal layer…
Switching regulator with automatic multi mode conversion
Granted: May 17, 2011
Patent Number:
7944191
Methods and apparatus are disclosed for efficient switching regulators that adapt automatically to, and operate with, input voltages that are above, below, or equal to the output voltage. The disclosed switching regulators demonstrate advantages of both buck and boost converters at high efficiency.
System and method for implementing a single-wire serial protocol
Granted: May 17, 2011
Patent Number:
7944807
Methods and apparatus for a single-wire serial communication system are disclosed herein. In one embodiment, a method includes defining a predetermined short pulse as data to be transmitted and a predetermined long pulse as a data separator for the data to provide serial communication for a data stream.
Method and apparatus for synchronous buck with active negative current modulation
Granted: April 19, 2011
Patent Number:
7928713
A circuit is disclosed that includes a buck voltage regulator electrically coupled to an active current modulator. The active current modulator is operable to detect a negative current in the low-side switch of the buck voltage regulator circuit during a light mode operation. Whenever the negative current is detected, the active negative current modulator causes the low-side switch to stay ON in a linear mode and limits the negative current to a predetermined current level.
Single-ended DC to AC power inverter
Granted: March 29, 2011
Patent Number:
7915833
An inverter comprising a low-side switching element in series with a first primary winding; a high-side switching element in series with a second primary winding, where the combination of the low-side switching element and first primary winding is connected in parallel with the combination of the high-side switching element and the second primary winding; and a clamping capacitor having one terminal connected to the first primary winding and having a second terminal connected to the…
Mode control circuit for switching regulators and method therefor
Granted: March 29, 2011
Patent Number:
7915873
A mode control method and apparatus for a switching regulator is disclosed. The method receives an input signal and amplifying the input signal to get an amplified signal. The amplified signal is sent to a sample circuit to get a sample signal. The sample signal is delivered to an averaging circuit to get an averaged sensed output signal. The averaged sensed output signal is compared with a first pre-determined threshold or an second pre-determined threshold to get a PWM enable signal.…
Method and apparatus for controlling a discharge lamp in a backlighted display
Granted: March 22, 2011
Patent Number:
7911150
The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is…
Method and apparatus for synchronous boost voltage regulators with active negative current modulation
Granted: February 22, 2011
Patent Number:
7893677
A switch-mode synchronous boost voltage regulator is disclosed that includes a boost voltage regulator and an active current modulator. The active current modulator detects a negative current flowing through the high-side switch during a light load condition. When the negative current is detected, the active current modulator is operable to maintain the high-side switch “on” in a linear mode and to limit the negative current to a predetermined current level.
Method and apparatus for fault detection scheme for cold cathode fluorescent lamp (CCFL) integrated circuits
Granted: February 22, 2011
Patent Number:
7894174
A fault detection circuit and a short-circuit detection circuit for a Cold Cathode Fluorescent Lamp (CCFL) driver integrated circuit having a power bridge and a CCFL load are disclosed that includes a reference circuit operable to generate a reference current in response to an external component, a replica component having a dimension substantially less than the components of the power bridge, a multiplexer circuit, and a comparator circuit. The replica component and the multiplexer…
Method for starting a discharge lamp using high energy initial pulse
Granted: February 1, 2011
Patent Number:
7880397
The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). Additionally, during striking of the CCFL, a higher energy initial energy pulse is used. During normal operation, a lower energy pulse is used.
Short circuit current ratcheting in switch mode DC/DC voltage regulators
Granted: February 1, 2011
Patent Number:
7880455
A regulator with a high side pass device and a low side pass device coupled in series to the high side pass device is disclosed. The apparatus further includes a control module coupled to the high side pass device and the low side pass device. The control module is coupled to the high side pass device and the low side pass device to control the high side pass device and the low side pass device. The control module is operable to lock out the high side pass device under certain…
DC/DC voltage regulator with automatic current sensing selectability for linear and switch mode operation utilizing a single voltage reference
Granted: February 1, 2011
Patent Number:
7880456
A switch-mode DC/DC converter and a linear low drop out (LDO) DC/DC regulator are connected in parallel to drive a single load. Both regulators share a common voltage reference, feedback network, input supply and output such that the regulated voltage is identical during each mode of operation. During heavy loads the switch-mode regulator is in operation and the linear regulator is disabled for the highest efficiency possible. Conversely at light loads the linear regulator is in…
Double-edge PWM controller and its control method thereof
Granted: February 1, 2011
Patent Number:
7880522
The present invention discloses a double-edge pulse width modulation (PWM) controller based on the output current and output voltage which is modulated in real time by the output current and the output voltage. The controller uses an extra first adder to sum up the compensation signal and a triangular signal (or a saw-tooth signal); a second adder to sum up the output current signal to a bias value; a PWM comparator, with its non-inverting input receiving the output of said first adder,…
Layout schemes and apparatus for high performance DC-DC output stage
Granted: February 1, 2011
Patent Number:
7882482
A layout method that enables a high power switch mode voltage regulator integrated circuit to generate a large output current and achieve substantially low switching loss is disclosed. The layout method includes forming an array of switching elements on a semiconductor die, each switching element including a plurality of discrete transistors configured to have a substantially reduced ON resistance; and forming a plurality of gate driver circuits on the same die among the switching…
High-impedance level-shifting amplifier capable of handling input signals with a voltage magnitude that exceeds a supply voltage
Granted: January 25, 2011
Patent Number:
7876152
A level-shifting amplifier is provided for level-shifting an input signal with a voltage magnitude that exceeds a supply voltage of the amplifier. In operation, the amplifier has an input impedance of greater than 100 MOhms.
Low-power voltage reference
Granted: January 18, 2011
Patent Number:
7872455
A circuit provides a voltage reference using very low power. It can also be used as a shut regulator for a quiescent current as low as 1.5 ?A. It includes a transconductance amplifier, a gain stage, and a power transistor. One embodiment of this invention utilizes a work function difference between p+ gate and n+ gate to generate a predetermined reference voltage. In another embodiment of this invention, the predetermined reference voltage can be pre-adjusted using gate materials with…
Method and apparatus for high performance class D audio amplifiers
Granted: November 30, 2010
Patent Number:
7843260
The present disclosure provides a method and apparatus for high performance class D audio amplifier circuit that includes: a modulator circuit for receiving a PWM input signal and generating a control signal, a driver control circuit, a switching circuit, and a feedback circuit. The driver control circuit is adapted to generate a drive signal for the switching circuit. The driving signal provides compensation for noise and distortions in a PWM output signal at each cycle by selecting…
