Abstract: The pulse-shaping look-up table with transient suppression (530) avoids hard turn-on and turn-off transients by modifying word segments of initial and final digital words during transmission of a digital data sequence. A controller (570) sends a mode signal and a digital data sequence to the pulse-shaping look-up table with transient suppression (530). A mode buffer and command block (560) uses the mode signal to control the creation of initial and final digital words created by a data buffer and control block (550) from the digital data sequence. The digital words are used by a look-up table (540) to create a sampled digital output waveform sequence. The pulse-shaping look-up table with transient suppression (530) provides an accurate output waveform sequence with reduced spectral emissions even during start-up and shut-down of digital data transmissions.

Abstract: A method of transferring data between a first electrical component (16) and a second electrical component (18), which are both coupled to a common oscillator (62) that oscillates at a first frequency, the first electrical component (16) generating a first bit stream having a second frequency that is a fraction of the first frequency and having a first number of bits, generating an indicator signal having a third frequency that is a fraction of the first frequency and that is indicative of a type of data represented by the first bit stream, and coupling the first bit stream and the indicator signal to the second electrical component. The second electrical component (18) sampling the first bit stream and the indicator signal at a fourth frequency that is substantially identical to the second frequency, thereby recovering the first bit stream generated by the first electrical component (16) and determining the type of data contained in the first bit stream.

Abstract: A transient-suppressing mode switch (100) uses a state machine (120) in conjunction with a soft switch (114) to control a first mode signal sent from a first mode signal source (112) to a first soft switch input and a second mode signal from a second mode signal source (130) to a second soft switch input. When switching from a first mode to a second mode, the state machine delays the transition of the second mode signal from a constant zero value to a non-zero value until after the amplitude of the first mode signal at the first soft switch input has decayed to a sufficiently small value in order to reduce transients caused by switching.

Abstract: The pulse-shaping look-up table with transient suppression (530) avoids hard turn-on and turn-off transients by modifying word segments of initial and final digital words during transmission of a digital data sequence. A controller (570) sends a mode signal and a digital data sequence to the pulse-shaping look-up table with transient suppression (530). A mode buffer and command block (560) uses the mode signal to control the creation of initial and final digital words created by a data buffer and control block (550) from the digital data sequence. The digital words are used by a look-up table (540) to create a sampled digital output waveform sequence. The pulse-shaping look-up table with transient suppression (530) provides an accurate output waveform sequence with reduced spectral emissions even during start-up and shut-down of digital data transmissions.

Abstract: A transmitter (107) includes amplifying circuitry (203) and control circuitry (215, 217, 219) for biasing the amplifying circuitry (203) so that it operates closer to saturation with increased efficiency. The gate voltage signal (213), which provides a gate bias, is coupled to the amplifying circuitry (203) and is dynamically varied by the processor circuitry (219) in response to the value of the amplifier control voltage (211) coupled to the amplifying circuitry (203). The amplifier control voltage (211), which has a value for maintaining the output power of the amplifying circuitry (203) at a constant, is produced by the integrating circuitry (217) in response to a comparison of the detected power output signal (216) produced by the detecting circuitry (215) and the power output control signal (218) produced by the processor circuitry (219).

Abstract: Radiotelephones often are powered by batteries (12). When a radiotelephone is bumped, the battery (12) can lose electrical contact with the radiotelephone. When power is interrupted (40), a timer is started (42). When the power is reapplied (44), the timer is sampled (46) and compared against a predetermined period of time. If the power was interrupted for a short time, then the radiotelephone is turned on (50). If the power was interrupted for a long time, then the radiotelephone stays off (48). The timer in the circuit is implemented as an RC circuit (26) starts to discharge. If the voltage level falls below Vref, the radiotelephone will not turn on when the power is reapplied.

Abstract: The bidirectional clocking apparatus provides automatic sensing of whether a reference clock being generated by another circuit needs to be divided down to a lower frequency. If this is true, the clock is divided down to a lower frequency and sent out to other circuits requiring the lower frequency clock. If the lower frequency clock is already generated from another circuit, the apparatus accepts this clock for use by other circuits. Only one terminal is required for either sourcing or accepting this lower frequency clock signal.