Abstract: An object detecting device utilizes a pyroelectric sensor providing a sensing current, a voltage amplifier providing an amplified voltage proportional to the sensing current, and a level monitor providing a detection signal when the amplified voltage exceeds a detection threshold. The device has a standby mode where the voltage amplifier receives a limited source current to provide the voltage of low amplification, and the level monitor provides a wake-up signal when the low amplified voltage exceeds a preliminary threshold lower than the detection threshold. In response to the wake-up signal, the device is switched to an operation mode where the amplifier receives a rated source current to provide a voltage of high amplification for comparison with the detection threshold. Thus, the amplifier is kept to be less-power consuming in the absence of the wake-up signal, reducing a power requirement.

Abstract: An object detecting device utilizes a pyroelectric sensor providing a sensing current, a voltage amplifier providing an amplified voltage proportional to the sensing current, and a level monitor providing a detection signal when the amplified voltage exceeds a detection threshold. The device has a standby mode where the voltage amplifier receives a limited source current to provide the voltage of low amplification, and the level monitor provides a wake-up signal when the low amplified voltage exceeds a preliminary threshold lower than the detection threshold. In response to the wake-up signal, the device is switched to an operation mode where the amplifier receives a rated source current to provide a voltage of high amplification for comparison with the detection threshold. Thus, the amplifier is kept to be less-power consuming in the absence of the wake-up signal, reducing a power requirement.

Abstract: A motor drive circuit, in which a first transistor at a drive stage, a second transistor at an output stage to be driven by the first transistor and a third transistor downstream the output stage for a short braking operation are formed in a common substrate or a common well of the substrate, a region of either a P type or an N type in either the substrate or the well is connected with the first transistor via a conductor so that a parasitic transistor is formed in which the substrate or the well serves as its base, whereby a current flowing from the first transistor to the second transistor during the short braking operation is sinked by turning on the parasitic transistor.

Abstract: There is disclosed a motor drive circuit, into which an output circuit for supplying a drive output to a motor is incorporated, having a temperature compensating circuit or an output current regulating circuit added to a transistor, interposed between a servo IC for generating a servo signal and the output circuit, for supplying the output circuit with a drive current corresponding to the control output. A dependency on the temperature is obviated by arbitrarily setting an operating point of the output current and compensating temperature characteristics, and the motor is thereby protected from an excessive current.