Abstract: At least some embodiments include a LED driver system. The system includes multiple branches of series-coupled LEDs, multiple current sources, and control logic. Each of the current sources is coupled to a separate branch of series-coupled LEDs. The control logic is coupled to the current sources, and is configured to regulate current through each branch based at least in part on a feedback voltage measured at a node in one of the branches.

Abstract: At least some embodiments include a LED driver system. The system includes multiple branches of series-coupled LEDs, multiple current sources, and control logic. Each of the current sources is coupled to a separate branch of series-coupled LEDs. The control logic is coupled to the current sources, and is configured to regulate current through each branch based at least in part on a feedback voltage measured at a node in one of the branches.

Abstract: A power management bus for controlling power over multiple device subsystems includes a master power bus controller which transmits power management information to control one or more power resources through a transmit interface. The transmitted information is received at one or more receive interfaces. A broadcast message can be transmitted to control multiple power resources by subsystem, resource group and resource type. A single address message can be transmitted to control a single power resource. A power down can be initiated at any of the receive interfaces.

Abstract: A power management bus for controlling power over multiple device subsystems includes a master power bus controller which transmits power management information to control one or more power resources through a transmit interface. The transmitted information is received at one or more receive interfaces. A broadcast message can be transmitted to control multiple power resources by subsystem, resource group and resource type. A single address message can be transmitted to control a single power resource. A power down can be initiated at any of the receive interfaces.

Abstract: At least some embodiments include a LED driver system. The system includes multiple branches of series-coupled LEDs, multiple current sources, and control logic. Each of the current sources is coupled to a separate branch of series-coupled LEDs. The control logic is coupled to the current sources, and is configured to regulate current through each branch based at least in part on a feedback voltage measured at a node in one of the branches.

Abstract: A wireless telephone (10) including audio amplifier circuitry (20) that produces reduced “pop” noise in speakers such as in handsfree headsets (HS) is disclosed. The audio amplifier circuitry (20) includes an audio amplifier (22) that drives the headset speaker (HSS). A first transistor (26) has its source-drain path connected between an output (HSO) of the audio amplifier (22) and a power supply voltage (Vdd), and a second transistor (28) has its source-drain path connected between the amplifier output (HSO) and a reference voltage such as ground. The first and second transistors (26, 28) are controlled by control logic (24), in response to the state of various register locations (30) that indicate the powered-up and enabled state of the audio amplifier circuitry (20). Normal and automatic modes for the precharge control are available, with the automatic mode eliminating the need for the precharge enable register location (30d) being written during operation.

Abstract: A mobile communications device (50) includes a plurality of LDOs (30) for supplying a stable voltage to various circuits on the device. In a normal mode, the LDO's main bandgap voltage source (12) supplies a voltage to a main amplifier (16). During deep sleep mode, sleep logic (40) places the LDOs in a sleeping state, where a low current sleep bandgap voltage source (32) supplies a voltage to a smaller, sleep amplifier (36), which maintains a charge on capacitors (24, 26) for a fast transitions to a full ON state.

Abstract: A mobile communications device (50) includes a plurality of LDOs (30) for supplying a stable voltage to various circuits on the device. In a normal mode, the LDO's main bandgap voltage source (12) supplies a voltage to a main amplifier (16). During deep sleep mode, sleep logic (40) places the LDOs in a sleeping state, where a low current sleep bandgap voltage source (32) supplies a voltage to a smaller, sleep amplifier (36), which maintains a charge on capacitors (24, 26) for a fast transitions to a full ON state.

Abstract: A wireless telephone (10) including audio amplifier circuitry (20) that produces reduced “pop” noise in speakers such as in handsfree headsets (HS) is disclosed. The audio amplifier circuitry (20) includes an audio amplifier (22) that drives the headset speaker (HSS). A first transistor (26) has its source-drain path connected between an output (HSO) of the audio amplifier (22) and a power supply voltage (Vdd), and a second transistor (28) has its source-drain path connected between the amplifier output (HSO) and a reference voltage such as ground. The first and second transistors (26, 28) are controlled by control logic (24), in response to the state of various register locations (30) that indicate the powered-up and enabled state of the audio amplifier circuitry (20). Normal and automatic modes for the precharge control are available, with the automatic mode eliminating the need for the precharge enable register location (30d) being written during operation.

Abstract: A mobile communications device (50) includes a plurality of LDOs (30) for supplying a stable voltage to various circuits on the device. In a normal mode, the LDO's main bandgap voltage source (12) supplies a voltage to a main amplifier (16). During deep sleep mode, sleep logic (40) places the LDOs in a sleeping state, where a low current sleep bandgap voltage source (32) supplies a voltage to a smaller, sleep amplifier (36), which maintains a charge on capacitors (24, 26) for a fast transitions to a full ON state.