Texas Instruments Corporation

Qualcomm Incorporated

Jialei Xu

Michael John Shay

Chunping Song

Stuart Pullen

Randy A Chappel

Ta-Tung Yen

Neal L Horovitz

Steve Hawley

Shashank Prakash Mane

Michael Bui

An apparatus is disclosed for operating a charge pump in a high-efficiency low-ripple burst mode. In an example aspect, the apparatus includes a charge pump with a flying capacitor, a switching circuit, and a burst-mode controller. The switching circuit is coupled to the flying capacitor and configured to selectively: be in a burst configuration to charge and discharge the flying capacitor based on a clock signal; or be in a pulse-skipping configuration. The burst-mode controller is coupled to the switching circuit and configured to trigger the switching circuit to transition from the pulse-skipping configuration to the burst configuration at a time that occurs between rising edges of the clock signal. The burst-mode controller is also configured to cause charging of the flying capacitor to occur for approximately half a period of the clock signal responsive to triggering the switching circuit to transition from the pulse-skipping configuration to the burst configuration.

High-efficiency low-ripple burst mode for a charge pump

In an actuator driver array, each actuator driver includes a transition stage to initiate a state change of a driver output signal, a static stage to maintain the state change, and an isolation resistor to couple the driver output signal to an output node of the actuator driver during a static mode. In an array of pad capacitors, each pad capacitor has: a first terminal at a connector pad communicatively coupled to the output node; and a second terminal coupled to an RF ground rail. The isolation resistor and the pad capacitor form a low-pass filter to filter RF harmonics from a respective actuator driver to respective actuator circuitry, and to filter RF energy generated outside of the respective actuator driver to its output node. In an RF actuator array, a state of each element is controllable by a corresponding actuator driver in the actuator driver array.

Dual-mode filtering actuator driver apparatus, systems and methods

Certain aspects of the present disclosure generally relate to reducing the size of parallel charging circuits for charging a battery in a portable device, while still effectively providing input current sensing and reverse current blocking capabilities. One example battery charging circuit generally includes: (1) a first charging circuit comprising a first charging output connectable to a battery and a first converter to provide power to the first charging output; and (2) a second charging circuit comprising a second charging output connectable to the battery, a second converter to provide power to the second charging output, a first transistor coupled between an output of the second converter and the second charging output, and a current-sensing circuit coupled to the output of the second converter to sense a current through the first transistor.

Master-slave charging circuit with slave charger input current sensing and adaptive battery current limiting

Certain aspects of the present disclosure provide methods and apparatus for current sensing and error correction, or at least adjustment, for a switching regulator. One example current-sensing circuit generally includes a first amplifier, a buffer, a low-pass filter, a first switch coupled between an output of the first amplifier and an input of the buffer, a second switch coupled between the output of the first amplifier and an input of the low-pass filter, a third switch coupled between an output of the buffer and the input of the low-pass filter, and a fourth switch coupled between the input of the low-pass filter and a reference node for the circuit.

Error correction for average current sensing in a switching regulator

In described examples, a multi-stage charge pump includes first, second and third charge pump stages connected in series. Each of the first, second and third charge pump stages includes a charge pump circuit of a first type that increases an input signal of a respective charge pump circuit by up to a given amount. The multi-stage charge pump also includes a level shifter that swings a level clock signal between a voltage of an output signal of the third charge pump stage and one of an offset voltage and ground. The multi-stage charge pump further includes a charge pump circuit of a second type that increases the voltage of the output of the third charge pump stage by up to another amount and provides an output and the other amount is set by the level shifter. Also, the multi-stage charge pump includes a charge pump circuit of a third type.

Multi-stage charge pump

A dual-mode driver includes a transition stage and a static stage. The transition stage switches a bias voltage or an RF ground potential to an output pad to change the state of an RF actuator device connected at the output pad. After waiting a predetermined period of time for the RF actuator device to change state, the transition stage of the driver is disabled. A high-side or low-side static stage transistor maintains the driver output state through an isolation resistor. The isolation resistor and a capacitor formed at the driver output pad form an RC low-pass filter to block spurious noise generated at the driver. The RC filter also blocks RF energy that might otherwise enter the actuator driver from the actuator. Some embodiments also include a second RC filter located proximate to the output pad to prevent RF energy generated in the RF actuator from entering the driver.

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Cupertino, CA, United States of America

Jialei Xu