PWM buck regulator with LDO standby mode
Granted: June 20, 2006
Patent Number:
7064531
A voltage regulator is disclosed having a PWM portion and an LDO portion on a single chip. The PWM portion switches a large MOS transistor (or synchronous MOS transistors) at a high frequency to supply medium and high currents (e.g., 600 mA) to a load. During a standby mode, the regulator switches to an LDO mode and disables the PWM portion. The LDO mode controls a very small MOS series transistor to supply the standby mode current. Since the gate of the series MOS transistor is small,…
JFET controlled schottky barrier diode
Granted: June 20, 2006
Patent Number:
7064407
A JFET controlled Schottky barrier diode includes a p-type diffusion region integrated into the cathode of the Schottky diode to form an integrated JFET where the integrated JFET provides on-off control of the Schottky barrier diode. The p-type diffusion region encloses a portion of the forward current path of the Schottky barrier diode where the p-type diffusion region forms the gate of the JFET and the enclosed portion of the forward current path forms the channel region of the JFET.…
Method of making truncated power enhanced drift lateral DMOS device with ground strap
Granted: June 13, 2006
Patent Number:
7060545
A method and system for providing a power enhanced lateral DMOS device is disclosed. The method and system comprise providing a semiconductor substrate with a plurality of source/body structures thereon. The method and system further comprise providing a slot in the semiconductor substrate between the plurality of source/body structures to provide a truncated source; and providing a metal within the slot to provide a ground strap device.
Method for optimizing the accuracy of an electronic circuit
Granted: May 23, 2006
Patent Number:
7049833
The present invention provides an apparatus and method for improving the accuracy of circuits. The apparatus includes a replicate circuit and a trim determination circuit. The trim determination circuit includes a measurable circuit element and determines the state of the measurable element. The replicate circuit includes a replicate circuit element which has similar electrical characteristics as the measurable element, and is configured to aid in determining an adjustable test current.…
Reducing transient current caused by capacitance during high speed switching
Granted: May 23, 2006
Patent Number:
7049858
An isolation resistor is inserted in series between a current source and the emitters of bipolar switching transistors in a differential amplifier. The switching transistors may also be MOSFETs. The in-rush current through the resistor, due to a parasitic or added capacitance, creates a certain increased voltage drop across the resistor, reducing dv/dt and thus reducing the transient in-rush current into the capacitor. This results in reduced waveform distortion. Such an isolation…
Buried power buss utilized as a ground strap for high current, high power semiconductor devices and a method for providing the same
Granted: April 25, 2006
Patent Number:
7033901
A method and system for providing a ground strap on a semiconductor device is disclosed. The method and system includes providing a substrate region and providing an epitaxial (EPI) layer over the substrate region. The method and system includes etching a plurality of device structures in the EPI layer and providing a slot in the semiconductor substrate that is in contact with the substrate region. Finally, the method and system includes oxidizing the slot except at the bottom of the…
Current sense resistor circuit with averaging Kelvin sense features
Granted: April 18, 2006
Patent Number:
7031855
A current sense resistor circuit using Kelvin connection sense features provides an average voltage across net sense resistance and average voltage across net reference resistance to be available at the Kelvin connection points. The Kelvin connections can be used by a negative feedback gain loop to hold the average current through respective reference elements and sense elements substantially constant.
Integrated circuit including high voltage devices and low voltage devices
Granted: March 28, 2006
Patent Number:
7019377
An integrated circuit includes a high voltage Schottky barrier diode and a low voltage device. The Schottky barrier diode includes a lightly doped p-well as guard ring while the low voltage devices are built using standard, more heavily doped p-wells. By using a process including a lightly doped p-well and a standard p-well, high voltage and low voltage devices can be integrated onto the same integrated circuit. In one embodiment, the lightly doped p-well and the standard p-well are…
Current-limiting circuitry
Granted: March 21, 2006
Patent Number:
7015680
A field effect transistor (FET) driver circuit includes an error amplifier for providing a FET control signal and a current limiting amplifier for preventing excessive current flow through the FET. The current limiting amplifier generates an overcurrent signal when an excessive current is detected. In response to the overcurrent signal, a voltage control circuit adjusts the voltage at the output of the error amplifier to turn off the FET. Meanwhile, a pulldown circuit at an input of the…
Wide swing, low power current mirror with high output impedance
Granted: March 14, 2006
Patent Number:
7012415
A current mirror includes a serially connected diode-connected transistor of a first conductivity type, a saturated (fully-on) transistor of a second conductivity type, and a current source for providing a reference current. A gate voltage generated by the diode-connected transistor in response to the reference current is provided to the gate of a matching transistor. This causes the matching transistor to mirror the reference current. Meanwhile, an output transistor cascoded with the…
Device and method for improved serial bus transaction using incremental address decode
Granted: March 14, 2006
Patent Number:
7013355
An incremental or bit by bit address decode scheme allows each device on a serial bus to determine as soon as possible if it is the device being addressed by a master device. As each address bit is received serially into a device, it is immediately compared with a corresponding bit of the device's address. As soon as there is a bit not matching, the device in question is determined to not be the one addressed by the master device. It can then be disengaged from the communication process…
Resistance multiplier circuit and compact gain attenuator
Granted: March 14, 2006
Patent Number:
7012343
A resistance multiplier circuit coupled to a first node of a first circuit for providing a high-value resistance at the first node includes a first transistor, a second transistor being N times larger than the first transistor, and a resistor. In one embodiment, the first and second transistors are NPN bipolar transistors. The first transistor has its base and collector terminals coupled to the first node and an emitter terminal coupled to a second node. The second transistor has a base…
Common-mode feedback circuit
Granted: February 28, 2006
Patent Number:
7005921
A common-mode feedback circuit is provided for fully-differential operational amplifier stages of a multistage amplifier. A first stage of the circuit establishes a substantially constant current output level for a feedback generating stage of the circuit. An exemplary embodiment using MOSFET devices illustrates using a diode-connected MOSFET and mirror MOSFET first stage and a generating the current for a common-source connected MOSFET second stage connected to the respective outputs…
Integrated schottky diode using buried power buss structure and method for making same
Granted: February 21, 2006
Patent Number:
7002187
An integrated Schottky diode and method of manufacture of such a diode is disclosed. In a first aspect, a Schottky diode comprises a semiconductor substrate. The semiconductor substrate includes an epitaxial layer (EPI) on the substrate region. The diode includes a plurality of guard rings in the EPI layer and a plurality of oxidized slots. Finally, the diode includes metal within the plurality of slots to form a Buried Power Buss. A portion of the metal is completely oxide isolated from…
Elimination of recirculation current loss in load-shared switching mode power supplies
Granted: February 21, 2006
Patent Number:
7002263
In master-slave current-tracking load-share systems using switching power supplies, a method and apparatus for preventing current recirculation at light-load and no-load operational conditions. The slave power supply is run in a discontinuous mode when load current falls to light-load or no-load state, preventing the slave from sinking current, therefore preventing recirculation from the master to the slave. The slave power supply is run at a lower current level than the master,…
Circuit for driving a voltage controlled oscillator for frequency modulation
Granted: February 21, 2006
Patent Number:
7002416
A circuit provides an output signal for modulating the oscillation frequency of a voltage-controlled oscillator (VCO) in response to a control signal where the VCO includes a first voltage-controlled variable capacitance device for varying the oscillation frequency of the VCO according to the output signal. The circuit includes a charge pump providing a charge current to a first node, a first capacitor having a fixed capacitance and a second capacitor both coupled to the first node, and…
Wireless device and method using frequency hopping and sweep modes
Granted: February 7, 2006
Patent Number:
6996399
Device and method in a frequency hopping spread spectrum wireless communication system allow reception without the need to lock in synchronous steps with the frequency hopping channels. The transmitter will operate in the frequency hopping mode while the receiver operate in a frequency sweeping mode. The receiver has an IF pass band that effectively sweeps rapidly across the frequency hopping channels to intercept the active channel in the transmission spectrum. A less expensive radio…
Electrical field alignment vernier
Granted: January 10, 2006
Patent Number:
6984531
A test structure pattern includes a first comb having a first set of tines, and a second comb having a second set of tines of the same width and spacing as the first set of tines. When the test structure pattern is stepped between fields on a wafer, the first comb and the second comb at least partially overlap on photoresist over a scribe lane between the fields. When the photoresist is developed, the overlap of the first comb and the second comb generates a metal comb. Electrical…
Compensator to achieve constant bandwidth in a switching regulator
Granted: December 6, 2005
Patent Number:
6972974
A switching regulator includes a compensation circuit for applying a scaling factor to the loop gain of the feedback control loop of the regulator. In operation, the loop gain of the feedback control loop has a dependency on the input and output voltages of the switching regulator. The compensation circuit applies a function as the scaling factor where the function is a reciprocal function of the loop gain dependency on the input voltage and output voltage. In one embodiment, the loop…
Method and apparatus for delay adjustment and channel reordering in baseband communication receiving system
Granted: November 15, 2005
Patent Number:
6965651
Apparatus and method receives and reorders a multi-dimensional signal transmitted through a communication channel using a slicer/encoder coupled to a pair-swap and symbol alignment module. The slicer/encoder uses a code that reduces the number of bits for each symbol in the multidimensional signal as required to pass through the pair-swap and symbol alignment module that detects and corrects pair-swap and symbol misalignment in the multidimensional signal. Decoders reverse the encoding…
