Motorola Corporation

Other

Keith Edward Jackoski

Edgar Herbert Callaway, Jr

Scott R Humphreys

Gary L Pace

John Wayne Simmons

George A Drapac

Paul J Godfrey

Gerald Paul Schwieterman

A selective call radio ( ) includes receiver ( ). The receiver in turn includes an antenna ( ) for receiving a radio signal having a first operating frequency, an amplifier( ) coupled thereto for generating an amplified signal; and a frequency translation circuit ( ). The frequency translation circuit includes a selectivity filter ( ) and an integrated frequency conversion circuit ( ). The selectivity is coupled to the amplified signal for generating a filtered signal. The integrated frequency conversion circuit is coupled to the filtered signal and is incorporated into at least one IC (integrated circuit). The integrated frequency conversion circuit includes an oscillator ( ), a divider ( ), and a mixer ( ). A first input of the mixer is coupled to the filtered signal generated by the selectivity filter. The divider is coupled to the oscillator and its output is coupled to a second input of the mixer. The mixer generates an output signal having a second operating frequency, the second operating frequency having a frequency value different from the frequency value of the first operating frequency of the radio signal.

Selective call radio having an integrated frequency conversion circuit

An oscillator circuit (10) having an optimized start up time includes an inverting amplifier (12) coupled in parallel to a crystal (14), a first bank of capacitors (16) coupled to the crystal, and a second bank of capacitors (20) switchably coupled (18) in parallel to the frequency resonant network, wherein the second bank of capacitors has a higher capacitance load than the first bank of capacitors. The oscillator circuit may also include a processor (62) for controlling when the second bank of capacitors gets switched and coupled to the crystal.

Method and apparatus for optimizing an oscillator start up time

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

Growing community of inventors

Wellington, FL, United States of America

Keith Edward Jackoski