Texas Instruments Corporation

Other

Mehedi Hassan

Grant Evan Falkenburg

Fredrick W Trafton

Lundy Findlay Taylor

Shinya Morita

Eugene G Dierschke

Bryan E Bloodworth

Davy H Choi

John Kevin Rote

Bert White

Robert E Whyte, Jr

James E Chloupek

Cecil J Aswell

Gregory Swize

John H Berlien, Jr

Kevin William Ziemer

Joao Carlos Brito

Vincent T Ng

Tianhong Yang

Alaa-Eldin Y El-Sherif

Sreejish Sreenivasan

An electronic device includes a precision reference circuit, which contains a bandgap reference circuit and an offset-correction circuit. The bandgap reference circuit has an output that is coupled to provide a bandgap reference voltage and an intermediate node that is separated from the output by a transimpedance resistor. The offset-correction circuit is coupled to the bandgap reference circuit and includes a DAC. The DAC is coupled to the intermediate node and is also coupled to receive an external digital value. The external digital value determines a fraction of a correction current that will be passed by the DAC.

Precision reference circuit

An AFE chip for a smoke detector includes a DC/DC boost converter having a boost input, a boost output, and a boost upper power supply input. The boost input is coupled to a first pin that is adapted for coupling to a battery through an inductor and the boost output is coupled to a second pin. The DC/DC boost converter is configured to not switch when a voltage on the second pin is greater than a programmed boost voltage. A set of power regulator circuits have a power input, which is coupled to a third pin, and a power output. The third pin is adapted for receiving an input voltage, the power output is coupled to provide an internal voltage, and the set of power regulator circuits are further coupled to the boost upper power supply input.

Integrated circuit for smoke detector having compatibility with multiple power supplies

A system on a chip (SoC) for smoke detection includes power regulator circuits coupled to respective pins and analog sensor amplifier circuits that are each coupled to a respective pin of the pins coupled to the power regulator circuits. A first analog sensor amplifier circuit of the analog sensor amplifier circuits has a photoelectric amplifier circuit, a first LED driver and a second LED driver. The SoC also has a digital core that includes a digital logic circuit, register bits, and an MCU communication circuit. The MCU communication circuit is coupled to a data pin, the register bits are coupled to control or modify operation of the power regulator circuits and the analog sensor amplifier circuits, and the register bits are operable to be written to by an MCU.

System-on-chip for smoke alarm

An electronic device includes a voltage regulator circuit having a power NFET coupled between an upper supply voltage and a pre-regulator output node and a current source coupled in series with a diode element between the upper supply voltage and a lower supply voltage. A gate of the power NFET is coupled to a first node between the current source and a diode element. A bypass circuit includes a power PFET coupled between the upper supply voltage and the pre-regulator output node. A comparison circuit is coupled to turn the bypass circuit off when the upper supply voltage is greater than a regulation threshold voltage.

Pre-regulator for an LDO

An apparatus, method and system for retracting a read/write head () to a landing position of a disk () in a disk drive system () which includes an actuator () coupled with the head () for retracting in a first direction toward an outside diameter of the disk () and a second direction toward an inside diameter of the disk () in response to corresponding signals. A control device () coupled with the actuator () which is adapted for determining a retract direction for the read/write head (), wherein a first signal indicative of a first direction and a second signal indicative of a second direction is provided to the actuator (), the control device () further providing the first signal following a loss of power which energizes the disk drive motor () of the disk drive system and providing the second signal subsequent to providing the first signal for retracting the read/write head () to the landing position.

Retract method to reduce head friction with the disk for a hard disk drive

A hard disk drive energy recovery circuit, a method of recovering energy from a motor of a hard disk drive and a hard disk drive. In one embodiment, the hard disk drive energy recovery circuit includes (1) a spindle resolver that generates transition signals as a spindle motor of the hard disk drive rotates among angular regions, (2) a spindle region state machine, coupled to the spindle resolver, that receives the transition signals and generates rectifier drive signals based thereon and (3) a synchronous rectifier, coupled to the spindle region state machine, that employs the rectifier drive signals to recover electrical energy from the motor.

Efficient hard disk drive energy recovery circuit and method and a hard disk drive incorporating the same

A circuit ( ) provides digital signals indicative of slew rates of phase signals ( ) of H-bridge power drive transistors ( ) of motor windings ( ) of a mass data storage device ( ). The circuit uses up and down phase control signals (UP,DN) to initiate up and down voltage changes in the motor phase signals. A portion of the circuit ( ) produces a state change in a phase status output signal ( ) when the phase signal ( ) is less than a supply voltage ( ). A digital comparison circuit ( ) compares the phase status output signal ( ) and the up and down control signals (UP,DN), and produces respective rise and fall digital outputs ( ) when the up and down phase control signals and the phase status output signal are the same. The respective rise and fall digital outputs ( ) have state change timings that indicate rise and fall times of said motor phase signals (

Digital method of measuring driver slew rates for reduced test time

A protection system for an integrated circuit is disclosed. A detection system detects an overvoltage condition and provides an overvoltage condition signal to indicate a condition in which overvoltage protection may be desired. In response to the overvoltage condition signal, one or more variable resistance devices in the system, such as power devices of associated driver circuitry, are controlled to limit the voltage across such devices.

System and method for overvoltage protection of an integrated circuit

A system and method are provided for controlling operation of an actuator for retracting a read/write head of a hard disk drive system. One aspect of the system and method relates to controlling the actuator in response to a retract request command by first decelerating the actuator for a time period and then braking of the actuator for another time period. Another aspect of the system and method relates to controlling operation of the actuator during retract based on a sensed back EMF relative to a target back EMF, which may be selected by a user.

System and method for controlling an actuator motor during retract

A circuit combination ( ) is presented for providing digital signals indicative of slew rates of drive signals ( ) provided to H-bridge power drive transistors ( ) of motor windings ( ) of a mass data storage device ( ). The circuit combination includes a plurality of predriver circuits ( ) producing predrive signals according to a commutation sequence for connection to respective the power drive transistors ( ). A multiplexer ( ) is connected to selectively direct at least some of the drive signals to a multiplexer output port, and a digital comparison circuit ( ) receives the at least some drive signals from the multiplexer output port and produces a digital outputs ( ) having state time changes in dependence upon rise and fall times of the predriver output signals.

A control circuit for motor current including a circuit to generate a voltage to indicate the actual motor current, a first convert circuit to convert the voltage indicative of the motor current to a current, a compare circuit to compare the current indicating the motor current with a reference current and generate a difference current between the current indicating the motor current and the reference current, and a second convert circuit to convert the difference current to a voltage to indicate a difference in motor current from the reference current.

Current mode approach to spindle motor current control and rotor position sense

A voltage to current conversion circuit is described. The circuit comprises a first differential amplifier for receiving an input voltage and producing an output voltage, and a second amplifier for converting the output voltage of the first amplifier to a current. The transfer function of the voltage to current conversion circuit is proportional to an exponential function that depends on the input voltage. The circuit is temperature and process independent. In a first preferred embodiment, the first amplifier comprises a first transistor for receiving an input voltage at its base terminal, a temperature dependent current source coupled to the emitter of the first transistor, and a positive voltage supply coupled to the collector through a diode coupled transistor, and a second transistor paired with the first transistor and having a base terminal coupled to an input voltage terminal, an emitter coupled to a temperature dependent current source, and a collector coupled to a voltage supply. The output voltage is a differential signal taken from the collector terminals to the second amplifier, which comprises a third transistor coupled to a fixed current source, the base terminal for receiving the voltage output of the first amplifier, and an emitter coupled to a fourth transistor's emitter, the fourth transistor receiving the output voltage of the first stage at its base terminal, and the collector providing an output terminal. A feedback circuit is coupled to the emitters of the transistors of the third and fourth circuits and to the collector of a fifth transistor, the feedback circuit providing negative feedback to limit the current available at the output when the current through the feedback circuit exceeds a predetermined limit.

Temperature and process independent exponential voltage-to-current converter circuit

A monolithic light-to-digital signal converter (1.10) includes a photodiode array (1.24) having a plurality of sections with each section producing a current signal in response to incident light, a current-to-digital signal converter circuit (1.28) for converting selected ones of the current signals to a digital signal, and a control circuit (1.26) for scaling the digital signal in response to user supplied programming signals. The control circuit (1.26) also responds to user supplied programming signals to supply control signals to current-to-digital signal converter circuit (1.28). Current-to-digital signal converter circuit (1.28) is responsive to the control signals for combining selected ones of the current signals into a composite current signal and converting the composite current signal to a digital signal.

Monolithic light-to-digital signal converter

A system for driving a hard disk drive spindle motor is disclosed. The system comprises a spindle motor control circuit (120) and a spindle motor power circuit (220). The system also includes at least one disk (22) attached to a rotatable spindle (21) and a spindle motor (400) which receives power signals from the spindle motor power circuit (220) and controls the rotation of the spindle (21). The spindle motor control circuit (120) comprises a multiplexor (127) which transmits either a pulse width modulation signal or a current control signal in response to a mode selection signal, and a spindle predriver (125) which receives the multiplexor output signal and transmits spindle motor control signals to the spindle motor power circuit (220).

Growing community of inventors

Plano, TX, United States of America

Mehedi Hassan