STATISTICAL PHASE DETECTION AND STARTING ALGORITHM

    公开(公告)号:JPH1175390A

    公开(公告)日:1999-03-16

    申请号:JP18496798

    申请日:1998-06-30

    Abstract: PROBLEM TO BE SOLVED: To improve a method and equipment for starting the rotation of a rotor in a multi-phase DC motor, by controlling the operation of a three-phase DC motor. SOLUTION: A microcontroller 40 controls drive currents in coils 8, 9, 10 through a serial interface 54, a sequencer 56 and a predriver circuit 58. The microcontroller 40 supplies data from a port 60 to the serial interface 54, and the serial interface 54 generates signals based on the data and supplies the signals to the sequencer 56. The sequencer 56 has a set of 8-bit registers, and each register retains information for giving instructions to the predriver circuit 58 for making driving transistors 13, 14, 15, 16, 18 and 20 to either conducting state or non-conducting state.

    METHOD AND EQUIPMENT IN WHICH TRANSITION FROM PULSE WIDTH MODULATION TO LINEAR CONTROL IS IMPROVED

    公开(公告)号:JPH11206177A

    公开(公告)日:1999-07-30

    申请号:JP30258398

    申请日:1998-10-23

    Inventor: MENEGOLI PAOLO

    Abstract: PROBLEM TO BE SOLVED: To enable quick switching from a pulse width modulation mode to a linear control mode with high reliability, by installing a disable circuit which makes a voltage bias terminal charge a capacitor or connects the terminal with a supply source for discharge. SOLUTION: A circuit 50 has a frequency lock loop or a phase lock loop circuit 52 which respond to a zero-cross signal from a floating coil and supply pulses to a driver. The phase lock loop 52 supplies a signal whose frequency depends on the final RPM target to a motor. The phase lock loop 52 supplies pluses to a first input terminal of a comparater 54 and a first input terminal of a mutual conductance operational amplifier 58. Second input terminals of the comparater 54 and the transconductance operational amplifier 58 are connected with the output terminal of a detection buffer amplifier 68. The comparater 54 has an output terminal connected with the input terminal of a multiplexer MUXH 56.

    DMOS TRANSISTOR HAVING SCHOTTKY DIODE BODY STRUCTURE

    公开(公告)号:JPH10284731A

    公开(公告)日:1998-10-23

    申请号:JP8310798

    申请日:1998-03-30

    Inventor: MENEGOLI PAOLO

    Abstract: PROBLEM TO BE SOLVED: To prevent a parasitizer in the constitution of a DMOS transistor from being activated by forming a Schottky diode, together with a DMOS transistor standing in a row with the main body diode, on the same integrated circuit. SOLUTION: An opening is made by etching through a BPSG oxide layer 96 above an N -drain region 64, N -source regions 90 and 92, a P-region 88, and an epitaxial layer 60. That opening is positioned to expose a P-ring region 88 and a part of the epitaxial layer 60, a P -region 94, and a part of N -source region 90 and 92. Gate electrodes 84 are connected electrically in common by a proper contact, for example, such as a conductive mesh, a second level mutual connector, or the like. Metallic layers 98 and 100 are made, being stuck by a proper technique, suitably by PVD, thus a final DMOS transistor M can be obtained.

    BEMF RECTIFICATION DURING POWER-OFF PERIOD FOR PREVENTION PARASITIC EFFECT

    公开(公告)号:JPH11127591A

    公开(公告)日:1999-05-11

    申请号:JP18602898

    申请日:1998-07-01

    Abstract: PROBLEM TO BE SOLVED: To prevent parasitic effects when the power to a DC motor is turned down during a power-off period of the motor by clamping related power nodes to a reference voltage. SOLUTION: A BEMF control circuit 10 is provided with three input follower means 12, 13, 14, and the three means 12, 13, 14 are basically identical. The circuit 10 monitors the voltage on wires 70, 70', 70" corresponding to low-side driver output nodes A, B, C and continuously compares them with one another. If any one falls below the others, a current is produced via the current path corresponding to the circuit. A mirror circuit corresponding to the current path is provided with a transistor 30, 30' or 30", and a current passing through one of them causes a current passed via a corresponding mirror transistor 46, 46' or 46" to be varied, and controls the current passed through the collector of the respective transistor on the wire 72, 72', or 72". As a result, parasitic effect can be prevented, when power breakdown occurs.

    ADAPTIVE SLEW RATE CONTROL
    5.
    发明专利

    公开(公告)号:JPH1155984A

    公开(公告)日:1999-02-26

    申请号:JP15083998

    申请日:1998-06-01

    Inventor: MENEGOLI PAOLO

    Abstract: PROBLEM TO BE SOLVED: To reduce generation of undesired noise, by supplying a control current based on a control signal representing a motor speed, and supplying a control voltage based on the control current to a control terminal of a driving transistor via a transmitting circuit. SOLUTION: The gate of a transistor M2 is connected to an altspeed control signal representing a rotor speed. If the rotor speed is lower than a threshold speed, the control signal is low, and the transistor M2 is turned OFF. Meanwhile, when the rotor speed exceeds the threshold speed, the control signal becomes high, and the transistor M2 is turned ON. And, current via the transistors Q2, M2 starts to flow. Thus, a control circuit 15 controls a slew rate of the low side driving transistor in response to the rotor speed. And, the slew rare is reduced during a period of high current recalculation via a coil. Thus, generation of sound noise due to rapid ON and OFF of the switch is prevented.

    PROTECTION OF JUNCTION SEPARATION TYPE INTEGRATED CIRCUIT AGAINST PARASITIC ADVERSE INFLUENCE

    公开(公告)号:JPH1126603A

    公开(公告)日:1999-01-29

    申请号:JP12624298

    申请日:1998-05-08

    Inventor: MENEGOLI PAOLO

    Abstract: PROBLEM TO BE SOLVED: To avoid the parasitic effect such as below-ground effect of a junction separation type IC by forcedly turning on a specified driver transistor forming a part of a parasitic transistor. SOLUTION: An IC 10 comprises a sequence control circuit 16 having a three-phase full-wave bridge circuit 14 for driving a load 12 and elements for commutating the operation of elements of a bridge circuit for applying an accurately timed current generated by a feed Vcc to segments of the load 12. The circuit 16 has various control loops for operation of the IC 10 as a brushless motor driver circuit and often so-called peripheral circuits. The circuit 14 has power transistor drivers 18A-18C, 19A-19C for comparing with a lower current of the circuit 16 to flow, e.g. a considerable current of at least several amperes, thereby avoiding the adverse parasitic effect of an IC having power devices.

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