Abstract: A cascode current mirror circuit includes a cascode connected input stage (401) that operates to conduct an input current (400) in response to an input voltage of an input signal coupled to an effective transconductance of the cascode connected input stage (401). An input mirroring transistor (404) operates to control a mirror reference current (406) in response to the input voltage of the input signal. A diode connected transistor (409) coupled to a second control node of the cascode connected input stage (410) generates a control bias proportional to the mirror reference current (406) and to the input signal. A cascode connected output stage (411) has a first control node (413) coupled to the input signal and a second control node (414) coupled to the diode connected transistor (409) and the second control node (410) of the cascode connected input stage (401) for establishing an output current (415) that is substantially equivalent to the input current (400).

Abstract: A frequency synthesizer (100) is used for generating a plurality of signals operating at a plurality of frequencies that are integer multiples of a reference frequency. The frequency synthesizer (100) includes a plurality of phase lock loops coupled to a single phase error detector. The phase error detector (103) is connected to a reference signal (104), a first generated signal (116) and a sampler signal (136) derived from a second generated signal (132). The phase error detector (103) includes a shared counter (118), and first and second registers (106, 122) connected to the output of the shared counter (118). First and second phase lock loops (101, 105) are used for phase locking to the reference signal (104). The first and second phase lock loops (101, 105) derive phase error signals from the first and second registers (106, 122), thereby adjusting the first and second generated signals (116, 132).

Abstract: A selective call messaging peripheral (100) capable of receiving at least one message and communicating it to an electronic information processing device (200) comprises a microcontroller (105) including a processor (106) for executing a microcode program that controls operation of the peripheral and a receiver (103) that operates to receive and demodulate an information signal to provide a recovered information signal including an address signal and the message. A correlator (109) compares the recovered address signal with a predetermined address and generates an address detection, indicating selection of the peripheral.

Abstract: A current controlled variable frequency oscillator (260) operates at a characteristic frequency that is determined primarily by a scaled current. A filter cascade (320) receives the scaled current for setting a filter cascade frequency substantially equal to the characteristic frequency. Additionally, the filter cascade (320) receives a triangular signal at a non-inverting input, the filter cascade (320) converting the triangular signal into a sinewave signal. A lowpass filter (330) receives the scaled current for setting a lowpass filter frequency to a frequency substantially less than the characteristic frequency. The lowpass filter (330) also receives the sinewave signal and provides an average signal therefrom. A comparator (340) receives the scaled current, wherein the comparator (340) compares the sinewave signal and the average signal for providing a substantially squarewave signal therefrom.

Abstract: 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 sensor output signal is conditioned by a filter (401, 402) to generate a control signal representing an effective value of the input signal level received at the radio frequency amplifier (202). The control signal is then coupled to an amplifier output power level adjustment circuit (403) that operates to adjust a power gain of the radio frequency amplifier (202) in an unconditionally stable feed-forward manner 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 predetermined signal overload level.

Abstract: A selective call receiver (5) has a programmable baud detector (12, 14) which is programmed (30) to test (33) for an absence of a paging signal having a predetermined baud rate at a first falsing rate and the programmed (36) to test (38) for either the presence or absence of the signal at a second baud rate lower than the first falsing rate, wherein samples from the first test (33) are also used in the determination made by the second test (38).

Abstract: A selective call receiver (100) includes a radio frequency amplifier (202) having an output power level that is controllable in an unconditionally stable manner. The selective call receiver (100) includes a loading diode (403) coupled to an output of the radio frequency amplifier (202) and a feed-forward load control (201) coupled to an input of the radio frequency amplifier (202). The feed-forward load control (201) detects an input signal strength and regulates conduction of a current through the loading diode (403). In response to the input signal strength substantially reaching or exceeding a predetermined activation threshold corresponding with a predetermined input signal strength and a maximum output power level, the feed-forward load control (201) adjusts the current causing an impedance of the loading diode (403) to vary in a manner that causes the output power level to remain substantially constant.

Abstract: A selective call messaging peripheral (100) capable of receiving at least one message and communicating the at least one message to an electronic information processing device (200). An information signal is received and demodulated to provide a recovered information signal including an address signal and at least one message. A correlator (109) generates a detection indicating selection of the selective call messaging peripheral when the recovered address is substantially equivalent to a predetermined address. In response to selection of the selective call messaging peripheral (100), a PCMCIA communication interface (119) communicates the at least one message between the selective call messaging peripheral (100) and the electronic information processing device (200).

Abstract: A voltage track and hold circuit operates to track a tuning voltage and holding the tuning voltage (404) as a reference voltage (408). In the track mode, the track and hold circuit includes a first operational transconductance amplifier (401) and a first charge storage device (402) coupled to a first input (403) of the first operational transconductance amplifier (401). The first charge storage device (402) accumulates a charge that corresponds with the tuning voltage (404). A second charge storage device (405) is coupled to a second input (406) and an output (407) of the first operational transconductance amplifier (401). The second charge storage device (405) accumulates a reference charge such that the reference voltage (408) present at the second charge storage device (405) is substantially equivalent to the tuning voltage (404).

Abstract: In a radio telephone (100, 200) having a keypad (206) for receiving first information (302), a memory (112) for storing second information (313), and an intelligent editing function. There is provided a method of transmitting information representing a phone number using the intelligent editing function that selects a prefix mode when a phone number has been automatically entered and selects an appending edit mode when the information representing a phone number has been manually entered. The information is then edited to form a complete phone number (315), and transmitted (102, 104, 105, 106).

Abstract: A selective call receiver includes receiver circuitry (20) and decoder circuitry (32). The receiver circuitry (20) receives selective call signals, including reprogramming messages (100). The decoder circuitry (32) decodes the reprogramming messages (100) and produces data in response thereto. The data includes program information (110) and reprogramming data (112). A reprogrammable memory device (70) stores option information for control of various operational features of the selective call receiver. A processor (34) is coupled to the decoder circuitry (32) and the reprogrammable memory device (70) and reprograms the option information in response to the reprogramming data (112) and according to the program information (110).

Abstract: A method and apparatus in a selective call receiver allow a user to receive maildrop message without losing access to previously received but unread maildrop messages in the same message slot. The selective call receiver comprises an address correlator (107) which determines whether received selective call signals comprise an individual or maildrop address assigned to the selective call receiver. A message memory (122) comprises an individual message portion (126) having an individual memory directory (127) and a maildrop message portion (128) having a maildrop memory directory (129).

Abstract: A selective call receiver (100) comprising an information display (118) and a processor (106) operationally coupled to the information display (118). The information display (118) presents at least information representing an area map (402) with a plurality of operating regions (403, 404, 405) in which the selective call receiver can receive an information signal from a selected channel. Each region in the plurality of operating regions (403, 404, 405) corresponds to a predetermined selective call signaling channel that may be selected for operation by activating at least one user activated control (407). The at least one user activated control (407) is operationally coupled to the processor (106) for effecting selection and reception of the information signal on the channel associated with the selected region on the information display (118).

Abstract: A radio telephone communication system (200) having a base station (203) including at least one frequency agile time division duplex transceiver (207) for facilitating communication with at lest one radio telephone (100) on the at least one radio frequency channel. The radio telephone (100) scans a plurality of channels capable of being generated by the at least one frequency agile transceiver (207) to find an available channel and provide an indication representing a base station busy status when all the at least one frequency agile transceivers are in use. A base station busy status is indicated when one of a bidirectional time division duplex communication including a base station identification signal is being communicated by the at least one frequency agile transceiver or a unidirectional time division duplex communication including a base station identification signal is being communicated by the at least one frequency agile transceiver (207).

Abstract: A paging receiver (15) for receiving secure radio frequency (RF) communications comprises a receiver circuit (102) for receiving and demodulating a signal to obtain information. A memory device (108) is coupled to the receiver circuit (102) for storing the information. A de-encrypter (110) is coupled to the memory device (108) for de-encrypting the information and a decoder (112) is coupled to the de-encrypter (110) for decoding the de-encrypted information to derive a message. User input controls (120) selectably generate a user input signal. A controller (114) is coupled to the memory device (108) and the user input controls (120) for causing the memory device (108) to provide the information stored therein to the de-encrypter (110) in response to the user input signal being equivalent to a predetermined de-encryption signal.