FIELD OF THE DISCLOSURE

The technology of the disclosure relates generally to radio frequency (RF) power amplifier circuits.

BACKGROUND

Mobile communication devices have become increasingly common in current society for providing wireless communication services. The prevalence of these mobile communication devices is driven in part by the many functions that are now enabled on such devices. Increased processing capabilities in such devices means that mobile communication devices have evolved from being pure communication tools into sophisticated mobile multimedia centers that enable enhanced user experiences. The redefined user experience requires higher data rates offered by wireless communication technologies, such as long-term evolution (LTE) and fifth-generation new radio (5G-NR). To help realize the higher data rates, a mobile communication device may employ sophisticated power amplifiers (PAs) to increase output power of radio frequency (RF) signals (e.g., maintaining sufficient energy per bit) communicated by the mobile communication device.

Envelope tracking (ET) is a power management technique that can improve efficiency levels of the PAs to help reduce power consumption and thermal dissipation in the mobile communication device. As such, the mobile communication device typically includes one or more ET circuits configured to operate in various ET scenarios, such as single-transmit (STX) ET and/or dual-transmit (DTX) ET. Further, the mobile communication device may employ a number of charge pump circuits to support the ET circuits operating in the various ET scenarios.

Notably, the charge pump circuits may operate based on a battery. Each of the charge pump circuits may include one or more switches that may be toggled between open and closed positions according to the various ET scenarios. When a switch is closed, it can draw a battery current from the battery. In some cases, it may be desirable to measure the battery current flowing through one or more switches in the charge pump circuits to help determine various operational parameters of the mobile communication device. For example, by measuring the battery currents in the switches, it may help detect/debug certain operational issues when the mobile communication device undergoes a factory test. Further, by measuring the battery currents in the switches, it may also help generate/capture various statistics in the field to help fine-tune the mobile communication device for optimal performance.

SUMMARY

Embodiments of the disclosure relate to a digital current sensing circuit and related apparatus. In one aspect, a digital current sensing circuit can be configured to estimate a battery current in a coupled circuit based on a voltage corresponding to the battery current. More specifically, the digital current sensing circuit generates an analog sense current proportional to the battery current based on the voltage and digitally processes the analog sense current to generate a battery current indication signal indicative of an estimation of the battery current. In another aspect, a number of digital current sensing circuits can be provided in an apparatus to concurrently estimate a number of battery currents in a number of circuits (e.g., charge pump circuits). As a result, it may be possible to test, debug, and/or fine-tune the apparatus based on the estimated battery currents for improved performance.

In one aspect, a digital current sensing circuit is provided. The digital current sensing circuit includes a voltage input configured to receive a voltage corresponding to a battery current in a coupled circuit. The digital current sensing circuit also includes an analog current sensing circuit configured to generate an analog sense current proportional to the battery current based on the voltage. The digital current sensing circuit also includes a sense current processing circuit. The sense current processing circuit is configured to estimate the battery current in the coupled circuit based on the analog sense current. The sense current processing circuit is also configured to generate a binary word representing the estimated battery current in the coupled circuit. The sense current processing circuit is also configured to generate a battery current indication signal indicative of an estimation of the battery current in the coupled circuit based on the binary word.

In another aspect, an apparatus is provided. The apparatus includes a first voltage circuit coupled to at least one amplifier circuit. The first voltage circuit includes a first tracker circuit configured to generate a first modulated voltage at a first output node based on a first supply voltage. The first voltage circuit also includes a first charge pump circuit configured to generate a first current at the first output node. The first voltage circuit also includes a first digital current sensing circuit. The first digital current sensing circuit includes a voltage input configured to receive a voltage corresponding to a battery current in the first charge pump circuit. The first digital current sensing circuit also includes an analog current sensing circuit configured to generate an analog sense current proportional to the battery current based on the voltage. The first digital current sensing circuit also includes a sense current processing circuit. The sense current processing circuit is configured to estimate the battery current in the first charge pump circuit based on the analog sense current. The sense current processing circuit is also configured to generate a binary word representing the estimated battery current in the first charge pump circuit. The sense current processing circuit is also configured to generate a battery current indication signal indicative of an estimation of the battery current in the first charge pump circuit based on the binary word. The apparatus also includes a second voltage circuit coupled to the at least one amplifier circuit. The second voltage circuit includes a second tracker circuit configured to generate a second modulated voltage at a second output node based on a second supply voltage. The second voltage circuit also includes a second charge pump circuit configured to generate a second current at the second output node. The apparatus also includes a third charge pump circuit configured to provide the first supply voltage and the second supply voltage to the first tracker circuit and the second tracker circuit, respectively.

Those skilled in the art will appreciate the scope of the present disclosure and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures.

