Ahmad Bahai

Bio: Ahmad Bahai is an academic researcher from Texas Instruments. The author has contributed to research in topics: Power management & Electric power system. The author has an hindex of 5, co-authored 10 publications receiving 134 citations. Previous affiliations of Ahmad Bahai include National Semiconductor.

Where Analog Meets Digital: Analog?to?Information Conversion and Beyond

Abstract: Energy efficiency, long battery life, and low latency are key attributes of many emerging ultralow-power sensing and monitoring systems. Applications such as always-on reactive sensors for natural human?device interfaces, as well as multiple consumer and industrial applications for the Internet of Things (IoT), require ultralow-power designs beyond the promise of state-of-the art data converters.

Active cell and module balancing for batteries or other power supplies

Abstract: A system includes multiple power modules (502, 802a-802n), each having multiple power cells (504, 804) coupled in series. Each power module has a charge that is based on charges of the power cells in that power module. The system also includes multiple active cell balancing circuits (100, 200, 300, 806a-806n, 900), each configured to substantially balance the charges of the power cells in an associated one of the power modules. The system further includes an active module balancing system (800) configured to substantially balance the charges of the power modules by charging a first subset of the power modules and/or discharging a second subset of the power modules. The active module balancing system could include multiple module balancing circuits (808a-808n), each associated with one of the power modules and configured to charge or discharge its associated power module. A direct current (DC) bus (810) can be configured to transport DC power between the module balancing circuits.

Integrated High-frequency Reference Clock Systems Utilizing Mirror-encapsulated BAW Resonators

Abstract: This work introduces an integrated reference clock system using a 2.5 GHz mirror-encapsulated BAW (bulk acoustic wave) resonator as the frequency source. With acoustic mirrors also placed on top of the resonator, this symmetrical DBAR (dual-Bragg acoustic resonator) structure offers extra design freedoms to alter the resonator’s acoustic properties. A DBAR requires no cavity on either side of the resonator yet still immune to mass loading effect from contamination and assembly. This advantage enables cost-effective system integration by directly marrying a DBAR and a CMOS die in a plastic package. System chips utilizing DBAR as the high-frequency reference clocks are demonstrated here. With compensation algorithm and careful design of the package, these DBAR-based clocking systems can achieve ±25 ppm stability over the entire operation temperature range (including aging, solder shift, etc.), resulting industry’s first crystal-less BLE (Bluetooth Low Energy) radio chip.

3.1 An Integrated BAW Oscillator with <±30ppm Frequency Stability Over Temperature, Package Stress, and Aging Suitable for High-Volume Production

Abstract: Wireless sensor nodes with low power and small form factor are desirable for emerging IoT applications. These nodes usually consist of a processor, memory, radio, sensors, battery, and two quartz crystals: one at 32kHz to synchronize data transmission and the other in the MHz range to synthesize RF signals. SoC integration of the memory, processor, and radio is common; however the MHz crystal remains external, which makes up a significant portion of the entire wireless node size.

Ultra-low energy systems: Analog to information

Abstract: Ultra-low power systems and circuits are increasingly pivotal for many fast growing segments of semiconductor industry. A confluence of multiple technologies has brought the promising opportunity for pervasive connectivity of people and things closer than ever. Innovative system partitioning, advances in analog and digital circuit design, modern embedded sensing technologies and intelligent power management are critical to achieve the ambitious ultra-low power targets of the modern sensor nodes. In this review, we address some of the challenges and opportunities of ultra-low power system and circuit design.

Switching Circuits For Extracting Power From An Electric Power Source And Associated Methods

Abstract: An integrated circuit chip includes a first input port, a first output port, and first and second transistors electrically coupled in series across the first input port. The second transistor is also electrically coupled across the first output port and is adapted to provide a path for current flowing through the first output port when the first transistor is in its non-conductive state. The integrated circuit chip additionally includes first driver circuitry for driving gates of the first and second transistors to cause the transistors to switch between their conductive and non-conductive states. The integrated circuit chip further includes first controller circuitry for controlling the first driver circuitry such that the first and second transistors switch between their conductive and non-conductive states to at least substantially maximize an amount of electric power extracted from an electric power source electrically coupled to the first input port.

Method and system for providing local converters to provide maximum power point tracking in an energy generating system

Abstract: A method for providing maximum power point tracking for an energy generating device (202) using a local buck-boost converter (206) coupled to the device (202) is provided. The method includes operating in a tracking mode, which includes initializing a conversion ratio for the buck-boost converter (206) based on a previous optimum conversion ratio. A device power associated with the initialized conversion ratio is calculated. The conversion ratio is repeatedly modified and a device power associated with each of the modified conversion ratios is calculated. A current optimum conversion ratio for the buck-boost converter (206) is identified based on the calculated device powers. The current optimum conversion ratio corresponds to one of a buck mode, a boost mode and a buck-boost mode for the buck-boost converter (206).

Method and system for providing maximum power point tracking in an energy generating system

Abstract: A method for providing a maximum power point tracking (MPPT) process for an energy generating device (202) is provided. The method includes coupling a local converter (204) to the energy generating device (202). A determination is made regarding whether the local converter (204) is operating at or below a maximum acceptable temperature. A determination is made regarding whether at least one current associated with the local converter (204) is acceptable. When the local converter (204) is determined to be operating at or below the maximum acceptable temperature and when the at least one current associated with the local converter (204) is determined to be acceptable, the MPPT process is enabled within the local converter (204).

System and method for integrating local maximum power point tracking into an energy generating system having centralized maximum power point tracking

Abstract: A system for integrating local maximum power point tracking (MPPT) into an energy generating system having centralized MPPT is provided. The system includes a system control loop and a plurality of local control loops. The system control loop comprises a system operating frequency, and each local control loop comprises a corresponding local operating frequency. Each of the local operating frequencies is spaced apart from the system operating frequency by at least a predefined distance. For a particular embodiment, a settling time corresponding to the local operating frequency of each local control loop is at least five times faster than a time constant corresponding to the system operating frequency.

System and method for over-voltage protection of a photovoltaic system with distributed maximum power point tracking

Abstract: A solar panel array for use in a solar cell power system is provided. The solar panel array includes a string of solar panels and multiple voltage converters. Each voltage converter is coupled to a corresponding solar panel in the string of solar panels. The solar panel array also includes multiple maximum power point tracking (MPPT) controllers. Each MPPT controller is coupled to a corresponding solar panel in the string of solar panels. Each MPPT controller is configured to sense an instantaneous power unbalance between the corresponding solar panel and an inverter.