Abstract: 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.

Abstract: A code-controlled voltage divider (20) is disclosed. The voltage divider (20) includes an upper portion with a resistor (22) and a dummy switching transistors (23), which is biased to be in an on-state. A lower portion of the voltage divider (20) includes multiple parallel legs, each including a resistor (24) and a corresponding switching transistor (26) that has its gate receiving one bit of a digital control word. A decoder (30) may be provided within the voltage divider (20) to generate the digital control word from an incoming code word, for example from a central processing unit (10). The lower portion resistors (24) of the voltage divider (20) are binary-weighted, and the sizes of the corresponding switching transistors (26) are binary-weighted so that the portion of the series resistance of each parallel leg that is due to the on-resistance of the switching transistor (26) is substantially constant over all of the parallel legs.

Abstract: A class-AB MOS output stage that provides higher gain and significantly lower distortion. The class-AB MOS output stage includes a PMOS output transistor and an NMOS output transistor coupled between positive and negative supply voltages such that the MOS output transistors operate in a common source mode, a first biased class-AB control circuit coupled between the output transistor gates, a first current source coupled between the gate of the PMOS output transistor and the positive supply, a second biased class-AB control circuit, and a second current source coupled between the second control circuit and the positive supply. The second class-AB control circuit is coupled between the second current source and a non-inverting input of the output stage. The gate of the NMOS output transistor is employed as the inverting input of the output stage, which further includes two differential amplifiers for controlling the first and second current sources.

Abstract: A system provides primary and alternate control circuits to a controlled system through an output port. A monitoring circuit that monitors a parameter of the controlled system selects the control methodology. The primary control circuit, consisting of a primary active part and a regulator, and an alternate control circuit receive feedback from the controlled system. A switching mechanism, controlled by an output of the monitoring circuit, connects the appropriate control circuit to the controlled system and switches internal connections as needed. During alternate mode, a simulator of the controlled system as driven by the primary active control circuit provides an output representative of the output of the regulator that would cause the current output of the controlled system if the system were in primary mode. This simulator output is used when transitioning back to primary mode to minimize transients in the output of the controlled system.

Abstract: An electrostatic discharge (ESD) protection device formed in the semiconductor layer of a semiconductor-on-insulator device, wherein the semiconductor layer has first and second wells. A discharge circuit is formed in the first well, operable to discharge the ESD pulse to ground. A pump circuit is formed in the second well, operable to use a portion of an ESD pulse's voltage to pump current into the first well for allowing the discharge circuit to turn on uniformly. The discharge circuit has a plurality of body nodes to the first well. The pump circuit comprises an input pad for receiving a portion of the ESD pulse's voltage; an MOS transistor having source, gate and drain; a capacitor connected between the input pad and the gate, whereby a rising input voltage pulls the gate transiently high for pumping current into the first well; the source is connected to the body nodes of the discharge circuit, and the drain connected to the input pad.

Abstract: To apply a desired voltage at a node driving a load impedance, a voltage source providing the desired voltage is connected to the node. In addition, a current source supplying an amount of current that would be drawn by the impedance if the voltage source alone were connected across the impedance. As a result, the voltage source may be freed substantially from supplying current, which may be advantageously used in several situations. For example, the approach can be used to connect a voltage source directly to a high load without potentially requiring a buffer between the voltage source and the node. Alternatively, the approach can be used to apply the same desired voltage at each of multiple nodes connected in series using the same voltage source without being affected by the routing resistance generally present between each pair of the nodes.

Abstract: The present invention discloses a circuit (10) adapted to compensate for RMR variations and shunt resistance across the RMR comprising a first current source (idc1) coupled to a first resistor (r1), a second current source (idc2) coupled to a second resistor (r2), wherein the first resistor (r1) and the second resistor (r2) are coupled, a resistive sensor (RMR) coupled on either side to a third resistor (r3) and to a fourth resistor (r4), and a transconductance feedback block (GM) coupled to the resistive sensor (RMR), the third resistor (r3), and to the fourth resistor (r4).

Abstract: Improve the productivity and cost for the manufacturing of a semiconductor device referred to as a wafer level CSP. The manufacturing method for a semiconductor device related to this invention contains each of the processes that form a wiring (18) for the purpose of electrically connecting each electrode pad (10a) and external connecting terminals on top of a wafer (10) on which semiconductor elements are formed, connect conductive balls that are preformed by a separate process on top of this, and next, cover the above-mentioned wafer with a resin (32) such that the upper portion of the conductive supporting posts (30) are exposed. In a later process, solder balls (34) are arranged as external connecting terminals on the upper portion of the conductive supporting posts, and in the final process, semiconductor elements are formed by dicing the above-mentioned wafer along the boundary lines of the above-mentioned semiconductor elements.

Abstract: A class AB output circuit includes a P-channel pullup transistor (M13) having a source coupled to a supply voltage, a drain coupled to an output(10), a gate coupled to respond to an input signal on an input(9), an N-channel pulldown transistor (M1) having a drain coupled to the output, a source coupled to ground, and a gate coupled to respond to the input signal. A first N-channel transistor (M2) has a drain coupled to a gate of the output transistor and the supply voltage by means of a current source (8) and a source coupled to ground by means of a second current source (13). A first diode-connected N-channel transistor (M3), a second diode-connected N-channel transistor (M4), and a first level shifting circuit (17) are coupled in series between ground and a gate of the N-channel transistor, and a current source (7) is coupled between the first supply voltage and the gate of the first N-channel transistor.

Abstract: A method and circuit is provided for improving the control of the trimming procedure for various devices without the need for additional dedicated control pins. Instead, the trimming procedure is controlled through sensing of changes in current and/or voltage applied through the existing available pins or bondpads of the devices to determine whether a command for trim programming has occurred. As a result, package-level trimming of the devices can be conducted in standard device packages having low pin count configurations, such as operational amplifiers, instrumentation amplifiers, difference amplifiers, low drop-out regulators, voltage references and other similar types of devices. A device to be trimmed is configured with internal circuitry configured to sense changes in current and/or voltage in the output or supply voltage of the device, and a test system for applying changes in the current and/or voltage through the existing available pins or bondpads of the devices.

Abstract: An apparatus configured according to characteristics for driving a write head to write to a memory device includes: (a) a current directing circuit directing a write current through a first circuit path or a second including the write head in response to a first or second write signal; (b) at least one of: (1) an impedance system for including at least one impedance unit within each of the first and second current paths; and (2) a current system for including at least one circuit element between a locus at each end of said write head and a supply voltage; and (c) a control unit coupled with at least one of the impedance system and the current system for effecting the including for at least one of the impedance system and the current system to effect configuring the apparatus.

Abstract: A low distortion compression amplifier comprising an amplifier circuit having an input and an output, wherein an input signal is received at the input and amplified in accordance with a gain to form an output signal at the output. The amplifier circuit further comprises a comparator circuit operable to receive the output signal and generate a first control signal in response thereto. A digital gain control circuit is coupled to the amplifier circuit, and is operable to generate a digital gain control signal based at least in part on the first control signal. The gain control signal is then employed to modulate the gain of the amplifier circuit in a digital fashion. The invention also comprises a method of digitally controlling a gain associated with an amplifier circuit. The method comprises comparing an output signal to a threshold and modulating the gain in a digital fashion, wherein the gain is modulated up in a plurality of rates or down in a plurality of rates in response to the comparison.

Abstract: A CMOS circuit including a P-channel pull-up transistor (MP) and an N-channel pull-down transistor (MN) includes a first feedback circuit (6) producing a first delayed signal (V7) on the gate of the pull-down transistor (MN) to turn on the pull-down transistor (MN) a first predetermined amount of time after the pull-up transistor (MP) is turned completely off so as to prevent any shoot-through current from flowing through the pull-up transistor (MP) and the pull-down transistor (MN) and a second feedback circuit (4) producing a second delayed signal (V5) on the gate of the pull-up transistor (MP) to turn on the pull-up transistor (MP) a second predetermined amount of time after the pull-down transistor (MN) is turned completely off so as to prevent any shoot-through current from flowing through the pull-up transistor (MP) and the pull-down transistor (MN).

Abstract: A pulse width modulation (PWM) controller includes a shutter circuit interposed between a PWM modulator and a driver circuit. The shutter circuit receives a raw PWM output signal from the PWM modulator and processes the raw PWM signal to eliminate double pulsing that may be present on the raw PWM signal. Bypass logic responsive to a switch or software controlled enable input is provided to permit the shutter circuit to be included in the PWM controller or alternatively, to be bypassed.

Abstract: A system and method are disclosed to limit a maximum duty cycle and/or provide a volt-second clamp for a pulse-width modulated (PWM) signal. Depending on the circuit topology, this approach can limit the absolute duty cycle or operate as a volt-second clamp in which the duty cycle is limited as a function of a variable input control voltage, such as a line voltage. The duty cycle can be selectively programmed by setting one or more external reference components, such as one or more respective resistors. Additionally, through component matching, desired clamping can be achieved with a high level of accuracy.

Abstract: A method and circuit for gain and/or offset correction in a CDAC circuit are provided. The gain and/or offset correction can be realized by adjusting the sampling capacitance of a capacitor array, with a positive array of the CDAC circuit being trimmed for gain correction, and a negative array of the CDAC circuit being trimmed for offset correction. Accordingly, corrections to variations in gain and/or offset caused by process variations can be suitably addressed. To facilitate gain correction, an exemplary CDAC circuit comprising an N-bit capacitor array includes on the positive side of the capacitor array an additional capacitor configured to capture the sampling voltage. An exemplary CDAC circuit can also be configured to have one or more capacitors shifted out of the total capacitance of the capacitor array, and thus reduce the amount of charge stored during sampling.

Abstract: The present invention comprises a circuit and method for controlling current to a load. In an exemplary embodiment, the circuit makes the maximum charge time (“MCT”) of a battery charging circuit (100) a function of the charging current. The MCT changes as the battery charging current changes. For low current the MCT would increase and for high current the MCT would decrease. The result is that MCT will always occur a short time after the battery is fully charged. In operation, the charging current can also be made a function of the temperature of devices within the charging circuit.

Abstract: Disclosed is a method of measuring the time signal of an electronic device including steps for measuring a true signal and an inverted signal. The measured true path signal and inverted path signal are combined to reduce measurement error and provide an accurate measurement of the time signal of the device under test. Also disclosed is an interface for use between a device-under-test and test equipment. The interface includes means for alternately switching a time signal from the device-under-test to provide a true signal path and an inverted signal path for measurement. A system embodiment of the invention is also disclosed in which an interface and measuring means are used to alternately measure and combine a true signal and an inverted signal to provide an accurate time measurement result.

Abstract: A circuit for closing a relay when an active AC voltage connected to one of the contacts of the relay is approximately zero volts includes a monitoring circuit that monitors the active AC voltage and outputs a phase-shifted voltage that crosses zero volts at predetermined times before the active AC voltage traverses zero volts. A pulse generating circuit initiates a pulse when the phase-shifted voltage enters a predefined voltage region and terminates the pulse when the voltage exits that region. An input signal is strobed onto the control input of the relay by the pulse so that the relay changes state coincident with the zero crossing of the active AC voltage.

Abstract: A complementary output stage in integrated circuit includes a P-channel transistor (MP1) the segmented into a first group of sections (MP1-1,2 . . . 12) and an N-channel transistor (MN1) segmented into a second group of sections (MN1-1,2 . . . 12). The sections of the first group are disposed in a plurality of N-type well regions (35), respectively, and the sections of the second group are disposed in a plurality of P-type well regions (36), respectively. The sections of the first group are alternately located with respect to the sections of the second group so as to form an interdigitated output stage area of the integrated circuit including the P-channel transistor (MP1) and the N-channel transistor (MN1) so that the higher amount of heat normally generated in the N-channel transistor is dissipated over the entire interdigitated output stage area and reduces peak temperatures in the N-channel transistor.