Motorola Corporation

Other

Gary L Pace

Edgar Herbert Callaway, Jr

David H Overton

James David Hughes

Vance H Peterson

Silvia M Viteri

Barry W Herold

Joan S DeLuca

John M McKee

Charles W Mooney

Gregory O Snowden

Kevin T McLaughlin

Walter J Grandfield

George A Drapac

George W Smoot

Pha C Nguyen

Frederick Loring Kampe

Pamela A Rakolta

Paul J Godfrey

William W Tan

Keith Edward Jackoski

Brian P Lenhart, Jr

Margaret Graham-Meighan

George W McClurg

Larry Charles Robbins, Jr

James E Berry

Wei Len Tan

An adaptive gate drive for an inverter includes control circuitry having a Field Programmable Gate Array (FPGA) and includes power circuitry having a plurality of FETs for operating a switching device, such as a Trench Gate Insulated Gate Bipolar Transistor (IGBT device). The control circuitry provides switching signals for operating the switching device. In addition, the control circuitry receives signals of output current of the IGBT device, temperature of the IGBT device, and DC link voltage. The FPGA has a plurality of operating points stored therein. Each operating point has corresponding parameters for a control signal that is used to control the turn-on or turn-off behavior of the IGBT device. During operation, the control circuitry compares the measured current, voltage and temperature operating points stored in the FPGA and sends the corresponding parameters to the gate drive circuit. The gate drive modifies the signal on the gate of the IGBT accordingly and thereby optimizes the turn-on and/or turn-off behavior of the device based on actual operating conditions.

Adaptive gate drive for switching devices of inverter

A selective call receiver (100) operating from a battery (102), includes a battery monitor (114), a radio receiver (108), a regulator (104), a capacitor (105) coupled to the regulator and the radio receiver, and a processor (116) for controlling the foregoing elements. The processor is adapted to determine from the battery monitor an energy level of the battery, configure the regulator to supply a first limited current to the radio receiver and the capacitor for a first predetermined time when the energy level is above a predetermined threshold, or configure the regulator to supply a second limited current to the radio receiver and the capacitor for a second predetermined time when the energy level is at or below the predetermined threshold. After configuring the regulator, the processor is then adapted to enable the regulator to charge the capacitor and to power the radio receiver.

Apparatus for improving the battery life of a selective call receiver

A driver circuit (100) is utilized to drive a high current load (116) in an electronic device powered by a battery (118) having a terminal voltage which varies in relation to a level of energy being consumed. The driver circuit (100) includes a differential amplifier (110) which is responsive to a predetermined reference voltage and to the terminal voltage for generating a drive control signal which proportionally reduces a current supplied to the high current load (114) when the terminal voltage is substantially equal to and lower than the predetermined reference voltage. A slope control element (112) is coupled to the differential amplifier (110) to control a rate at which the drive control signal reduces proportionally the current supplied to the high current load (116). A load control element (114), coupled to the differential amplifier (100), provides the supply of current to the high current load (116).

Driver circuit providing controllable battery overload protection

A selective call receiver (100) includes a radio frequency amplifier (202) having an output power level that is controllable. A radio frequency level sensor (500) generates a sensor output signal in response to an input signal level received at the radio frequency amplifier (202). The receiver also includes a RSSI signal (208) that indicates a relative strength of an on-channel signal received at the radio frequency amplifier and recovered by the selective call receiver. The amplifier output power level adjustment circuit that operates to adjust a power gain of the radio frequency amplifier (202) in an unconditionally stable feed-forward manner based on the sensor output signal and the RSSI signal, such that the output power level remains substantially constant when the input signal level sensed by the radio frequency level sensor (500) substantially reaches or exceeds a first predetermined signal overload level or the received on-channel signal substantially reaches or exceeds a second predetermined signal level.

Feed-forward RSSI assisted radio frequency amplifier power control

A receiver circuit (10), and method for automatic frequency control of a receiver circuit (10) suitable for receiving a radio frequency (RF) signal, featuring determination of at least one parameter other than a frequency error of a signal which is mixed with the RF signal received by the receiver circuit; and adjusting the frequency of the signal which is mixed with the RF signal based on the frequency error if the at least one parameter satisfies a predetermined criterion.

Method and apparatus for an automatic frequency control receiver

An electronic driver for use with linear and non-linear transducers includes a voltage controlled oscillator (1630) to generate an output signal (1603) in response to a frequency control signal (1625); a transducer driver (1604), coupled to the voltage controlled oscillator (1630) and to the transducer (600), includes an electromagnetic driver (604) to generate an electromagnetic field in response to the output signal (1603), and a power control circuit (2104, 2106) to suspend generation of the electromagnetic field for a portion of the output signal, the electromagnetic field generating movement of a magnetic motional mass (636) which is transformed into tactile energy; and a tactile energy monitor (1606) coupled to the electromagnetic driver (604) for monitoring a level of tactile energy generated by the movement of the magnetic motional mass (636), and in response thereto generates the frequency control signal (1625) to maximize the level of tactile energy generated.

Electronic driver for an electromagnetic resonant transducer

A zero-intermediate frequency receiver circuit (11) for receiving a radio frequency signal detected by an antenna (14). The receiver circuit (10) comprises a second local oscillator circuit (25) and an oscillator circuit (60) of a phase locked loop demodulator (36) which are identical and track each other so as to provide a more accurate reference for processing a demodulated signal. A current reference (39) providing a current reference signal utilized by the second local oscillator circuit (25) and the oscillator circuit (60) of the phase locked loop demodulator (36).

Zerox-IF receiver with tracking second local oscillator and demodulator

A phase locked loop (PLL) circuit for use as a demodulator and other applications. The PLL circuit (200) comprises a phase detector (210), a transconductance amplifier (212) and a current controlled oscillator (ICO) (214). The phase detector has two signal inputs and two outputs, and detects a phase difference between signals at its inputs. A capacitor C1 is connected to the output of phase detector (210) and develops an output voltage signal vo(t). A transconductance amplifier (212) is coupled to the capacitor C1 and converts the output voltage signal vo(t) to an output current signal. The ICO (214) is coupled to the transconductance amplifier (212) and the second output of the phase detector (210) and generates an output signal having a frequency which is proportional to an input current signal. The output signal of the ICO (214) is coupled to the second signal input of the phase detector (212).

Phase locked loop circuit current mode feedback

A high current driver (100) for driving a high current load (110) in an electronic device powered by a battery (112) comprises a voltage reference (104) for generating a reference voltage, and a drive current controller (102, 302) responsive to a drive control signal for selectively switching the drive current controller (102, 302) from an active state for supplying current to the high current load (110), to an-inactive state for inhibiting the supply of current to the high current load (110). The drive current controller (102, 302) further controls the amount of current supplied to the high current load (110) when the battery (112) terminal voltage is substantially equal to the reference voltage. A load control element (108) is coupled to the drive current controller (102, 302) and drives the high current load (110) when the drive current controller (102, 302) is in the active state.

High current driver providing battery overload protection

A peak and valley measuring circuit (40) featuring a single digital-to-analog converter (DAC) (100), a peak counter (110), a valley counter (120), and a comparator (130). The peak and valley measuring circuit (40) uses the peak counter (110) when detecting peaks of the recovered audio signal and the valley counter (120) when detecting valleys of the recovered audio signal. The DAC (100) is used in conjunction with one of the counters (110) or (120) depending on whether peaks or valleys are being detected, and is preferably a current-mode DAC.

Peak and valley signal measuring circuit using single digital-to-analog

A differential direct current (DC) offset compensation circuit for providing DC offset compensation to a circuit device (110). The DC offset compensation circuit (100) comprises a differential integrator (120) and a summing network (130). The circuit device (110) is one of several types of devices, such as a DC coupled amplifier. The differential input (112) of the circuit device (110) is suitable for coupling to a differential input source (140) and the differential output (114) of the circuit device is suitable for connection to a load (150). The differential integrator (120) features a transconductance amplifier (18) at least one other amplifier (13), and a capacitor element (16) having a capacitance of C1. The summing network (130) sums the differential integrator output with the differential input signals of the differential input source (140) and cancels DC offsets of the differential input source (140) and the circuit device (110).

Differential DC offset compensation circuit

A detector circuit (301) is utilized in a DC to DC converter (300) having an inductor (356) coupled to a switch (358) for interrupting an electric current through the inductor (356), thereby allowing the inductor (356) to transfer stored energy to a capacitive load (364). The detector circuit (301) includes a capacitor (302) coupled to the inductor (356) for generating a transient current (428) in response to a completion of a transfer of stored energy from the inductor (356). The detector circuit (301) further includes a reference current generator (306) for generating a reference current, and a summing node (304) coupled to the capacitor (302) and coupled to the reference current generator (306) for summing the transient current (428) and the reference current. The two summed currents form a transient control current (436) responsive to the completion (424) of the transfer of stored energy from the inductor (356).

Apparatus for detecting completion of energy transfer in an inductive DC

A differential transconductance amplifier consisting of a bipolar differential amplifier (110) and an active load circuit (120) for the bipolar differential amplifier (110). The transconductance amplifier is suitable for driving a load (130). The active load circuit (120) comprises a bipolar differential amplifier (140), a metal-oxide-silicon (MOS) amplifier (150), and a resistor R1. The active load circuit (120) generates active load currents IAL1 and IAL2. The output of the transconductance amplifier are the differential output currents I1 and I2 which are supplied to the load (130). Differential output currents I1 and I2 are the sum of the currents into the nodes between the bipolar amplifier circuit (110) and the active load circuit (120). The gain of the transconductance amplifier is controlled by a current source that biases the differential amplifier (110).

Fully differential transconductance amplifier with common-mode output

A non-contact pager programming system includes a controller (30) which is responsive to command and data signals to generate first signals (34) including command and data words to govern a transmitting circuit (36) to transmit over the air a programming signal (46) digitally modulated in accordance with a reception protocol. The programming system may also include a receiving circuit (42) which is governed by at least one second signal (40) generated by the controller to receive over-the-air signals (52) generated by the pager being programmed in response to the programming signal.

Non-contact pager programming system and a pager for use therewith

A temperature compensated current source (300) is provided that senses a first reference voltage (301) to control a second reference current (302). The current source comprises means (304, 305, 306) for deriving a first reference current (303) in response to the first reference voltage (301) and means (304, 305, 307, 309, 310, 311, 312, 313) for maintaining a desired temperature coefficient of the second reference current (302) by sensing the first reference voltage (301) to control the second reference current (302).

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Boca Raton, FL, United States of America

Gary L Pace