Allegro Microsystems, LLC

Other

Robert J Stoddard

Roger C Peppiette

Richard B Cooper

James McIntosh

Joshua J Wibben

Robert Douglas Christie

Timothy Reynolds

Lyndon Ambruson

William Boyd Alcorn

Robert Charles Ledzius

Greg Allen Hupp

Shalini Batra Sahni

Daniel P Orange, Ii

James Mcintosh

A motor drive circuit for driving an electric motor includes a plurality of driver circuits, each one of the plurality of driver circuit comprising a high side transistor coupled to a low side transistor in a half bridge arrangement, wherein each one of the high side transistors and each one of the low side transistors has a respective control node and respective first and second current passing nodes, wherein the second current passing node of each of the high side transistors is coupled to the first current passing node of a respective one of the low side transistors at a respective junction node, wherein each one of the plurality of driver circuits is operable to drive a respective current out of a respective junction node into a respective winding of the electric motor. The motor drive circuit further includes a capacitor coupled to the first current passing node of each one of the high side transistors, the capacitor operable to hold a capacitor voltage. The motor drive circuit further includes a power loss brake control circuit coupled to receive the capacitor voltage from the capacitor and operable to sense when a power supply voltage to the motor drive circuit is below a threshold voltage and, in a braking mode of operation, the high side transistors are off, and also in the braking mode of operation, when the power supply voltage is below the threshold voltage, the power loss brake control circuit is operable to generate at least one pulse signal having at least two state transitions and operable to communicate the at least one pulse signal to a respective at least one of the control nodes of a respective at least one of the low side transistors, resulting in on and off conditions of the at least one of the low side transistors, wherein the on condition of the at least one of the low side transistors results in the braking mode of operation during the on condition, and wherein the at least two state transitions results in a voltage boosting operation such that the capacitor voltage is a boosted voltage, the boosted voltage higher than a voltage that would be achieved without the at least two state transitions.

Electronic circuit for reducing rotation speed of an unpowered electric motor

Methods and apparatus for a voltage regulator having a boost module and a charge pump module. In embodiments, the charge pump module is configured to operate in multiple modes. In embodiments, an IC package includes the boost module and the charge pump with a shared component, such as a capacitor.

Voltage regulator having boost and charge pump functionality

Methods and systems for SDA of mixed signal electronic circuitry including embedded software designs for creating ASICs, sub-systems, and SoCs. The SDA system described extends IP reuse beyond the circuit and stand-alone verification capabilities that are common practice today which limit the benefits of reuse. By solving the integration problem first in a loosely coupled manner, complex mixed signal SoC devices may achieve higher levels of IP reuse with push button ease through the cloud, significantly improving time to market, design resource limitations, risks for first time silicon success, and the tasks of managing business multiple relationships of IP providers. SDA generated designs use a multi-agent method of operation, creating powerful and flexible designs that provide both NOC (Network on a Chip) and NBC (Network Beyond the Chip) for distributed system operation, and enhanced non-intrusive in-system monitoring for mission critical and safety related applications.

Methods and systems for system design automation (SDA) of mixed signal electronic circuitry including embedded software designs

Described embodiments provide an electronic circuit for controlling a motor. The electronic circuit includes a magnetic field sensing circuit responsive to magnetic field sensing elements disposed to sense rotation of the motor. The magnetic field sensing elements generate magnetic field signals, each having a state indicative of at least one of the rotational position and a rotation speed of the motor. A position and speed sensing circuit generates a signal representative of the rotational position of the motor and tracks state changes of the magnetic field signals. A gate driver circuit generates motor drive signals that drive the motor based upon the sensed rotational position. The position and speed sensing circuit generates a qualified control signal based upon a determined valid state change of the magnetic field signals. The gate driver circuit generates the motor drive signals based, at least in part, upon the qualified control signal.

Control timing and sequencing for a multi-phase electric motor

A regulator control circuit includes a switch control signal generator to generate a switch control signal and a soft start circuit to generate a soft start signal for use by the switch control signal generator. The soft start circuit includes a soft start controller and a decreasing circuit to decrease the soft start signal in response to the soft start controller. The soft start controller may comprise a non-regulation detector to detect a non-regulation condition. Embodiments include decreasing the soft start signal in response to a non-regulation condition lasting a predetermined time, detecting the non-regulation condition in response to a maximum duty cycle of the regulator switch, generating a soft start level indicator to control decreasing the soft start signal, and maintaining the soft start signal at a predetermined relationship with respect to a feedback signal.

Soft start circuits and techniques

A pulse width modulated (PWM) transistor driver circuit, for driving an inductive load, has a load-current sensing resistor and a comparator having an input connected to the sensing resistor and another input to which a PWM control reference voltage may be applied. A PWM driver-control circuit includes a set-dominant PWM latch, and a not.sub.-- regulating detector that may be composed entirely of logic circuit blocks or a combination of logic and analog circuits. By either means, the PWM bridge-control circuit includes a timer for repeatedly generating control pulses that set and hold a PWM latch beginning each PWM period, and the comparator resets the latch each time after the timer pulse the load current rises to exceed a corresponding reference voltage level. A sample-time-interval is defined beginning at the time of termination of a control pulse and a not.sub.-- regulating pulse generator produces a not.sub.-- regulating pulse only during the sample-time when the load current exceeds the level of the applied reference signal, indicating that the PWM system is failing to regulate the load current. Further, the not.sub.-- reg pulse width is, under most load conditions and over a wide range of applied reference voltage levels, a measure of the degree of failure of the PWM driver to regulate.

PWM driver for an inductive load with detector of a not regulating PWM

A bridge for driving one phase of a stepping motor includes a PWM driver control circuit that repeatedly turns on at least one of the driver transistors. A sense voltage is produced that is directly related to the bridge load current. When a driver-control reference voltage V.sub.ref is applied to the driver-control input, a sense-comparator pulse is generated when the sense voltage exceeds the applied reference voltage for turning off the one driver transistor. The remaining 'decay' portion of the PWM period ensues after the driver transistor turns off. A not.sub.-- regulating pulse is generated during a predetermined sample time portion of each driver on-time when the load sense voltage exceeds the applied V.sub.ref. In each PWM period, when a not.sub.-- regulating pulse occurs the bridge driver is operated in the four quadrant decay mode during an initial part of the PWM-period decay portion until time t.sub.m and operating in the two quadrant decay mode for the remainder of the PWM-period decay portion. The not.sub.-- regulating pulse may have a width that is directly related to the time interval during which the sense voltage exceeds the driver-control reference voltage, and the time t.sub.m may be delayed in the PWM period by an amount that is directly related to the not.sub.-- regulating pulse width, and/or delayed by an amount that is inversely related to the value of the applied V.sub.ref.

PWM inductive load bridge driver for dynamically mixing four and two

A bipolar driver circuit includes a primary driver transistor and an independently controlled pre-driver transistor having an emitter connected to the base of the primary driver transistor and a collector connected to the collector of the primary driver transistor. In one embodiment, the collector of the primary driver transistor is connected to the output terminal of the driver circuit for sinking current from a load and, in another embodiment, the emitter of the primary driver transistor is connected to the output terminal of the driver circuit for sourcing current to a load. A first current source is connected to the base of the primary driver transistor and a second current source is connected to the base of the pre-driver transistor. The current sources are commonly controllable by an input signal. Also provided is an inverse conduction prevention circuit for preventing the pre-driver transistor from diverting base current from the primary driver transistor in the sink driver embodiment.

Bipolar driver circuit including primary and pre-driver transistors

A semiconductor integrated circuit has a P-type substrate and a plurality of PN-junction isolated islands of N-type, a first one of the islands may contain a power device which during certain periods of operation causes the first island to become forward biassed and to inject electrons into the substrate. Collection of these injected charges by a second island at one side of the injecting island is reduced by a separate protective bipolar transistor formed in a third N-type island. The third island is preferably interposed between the injecting island and the islands to be protected, but may be located anywhere with respect to the injecting transistor. The emitter of the protective transistor is electrically connected to an N-type portion of the first island. The collector of the protective transistor is connected to the P-type isolation-wall portion of the substrate located between the injecting transistor and the small islands to be protected. The base of the protective transistor, and the isolation-wall portion of the substrate at the opposite side of the first island, are electrically connected to a circuit ground point in the integrated circuit. This causes preferential injection through that part of the forward biassed PN-junction of the injecting island, which part is farthest from the second island. It also generates a field under the first island, proportional to the magnitude of the injected current, that further diverts and prevents diffusion of the injected charges toward the second island.

Separate protective transistor

In an integrated circuit in which a first PN-junction-isolated island may momentarily become forward biased with respect to the surrounding substrate and inject unwanted charge that is collected by second islands adjacent one side of a first island, the injected charge is drawn away from the second islands and to a gatherer-collector island located at another side of the first island. The first island, gatherer-collector island and intervening substrate therebetween serve respectively as the emitter, collector, and base of a protective transistor. This transistor becomes a highly efficient collector of injected charge when the protective-transistor collector is hard wired to ground and the protective-transistor base is hard-wire connected to the substrate portion between the injecting first island and adjacent second island.

Growing community of inventors

Lincoln, MA, United States of America

Robert J Stoddard