Texas Instruments BQ500511RHAR

Overview

BQ500511RHAR from Texas Instruments is a wireless power transmitter controller IC designed for Qi-compliant WPC v1.2 A11 transmitters. It integrates digital control, Foreign Object Detection (FOD), Dynamic Power Limiting™ (DPL), and LED status indication, and operates with the bq50002 analog front end to drive a full-bridge power stage. It supports up to 5 W output, delivers >75% system efficiency, and targets compact 5-V wireless charging pads for smartphones and wearables.

For engineers reviewing the BQ500511RHAR datasheet, BQ500511RHAR pinout, BQ500511RHAR application, or BQ500511RHAR equivalent, key selection considerations include its 40-pin VQFN package, I²C interface, dual PWM/CLK outputs for frequency/duty-cycle control, FOD calibration via external resistors, and thermal shutdown capability via TSENSE input - all critical for robust, certified wireless power design.

Technical Context

The BQ500511RHAR implements closed-loop power regulation by dynamically adjusting operating frequency (110–205 kHz) while maintaining fixed 50% duty cycle until maximum frequency is reached. It communicates exclusively with receivers via bidirectional analog COMM1/COMM2 channels derived from the bq50002, not over I²C - which is used only for host configuration and status readback.

FOD operation relies on real-time loss estimation using measured input current (ISENSE), input voltage (VSENSE), peak coil voltage (VPEAK), and receiver-reported power; thresholds are set via resistor-divided voltages on FOD_THR (pin 35) and FOD_CAL (pin 10), enabling ±1000 mW/A load-dependent correction and 0–1000 mW absolute loss detection.

Key Specifications

Pinout & Package

The BQ500511RHAR is housed in a thermally enhanced 6.00 mm × 6.00 mm, 40-pin VQFN (RHA) package with exposed thermal pad for improved heat dissipation in high-power wireless charging applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar wireless power transmitter controller applications.

Compared with bq51013BRHAR and MP-A21, the BQ500511RHAR offers superior design flexibility through its split-architecture interface with bq50002, enabling optimized thermal management and higher efficiency (>75%) in compact 5-W systems - but requires careful coordination of two ICs and external FOD resistor selection.

Availability

BQ500511RHAR is available at Aetrix Electronics and suitable for smartphone charging pads, medical wearable bases, automotive in-car transmitters, and industrial IoT device chargers requiring stable component supply, long-term lifecycle support, and WPC v1.2 compliance assurance.

Supply support for BQ500511RHAR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company delivering analog and embedded processing solutions, with leadership in power management, signal chain, and wireless connectivity technologies.

The BQ500511RHAR belongs to TI's Wireless Power Transmitter Controller product line, engineered specifically to enable compact, efficient, and standards-compliant 5-V Qi v1.2 A11 charging systems in collaboration with the bq50002 analog front end.

FAQ

What is the role of the BQ500511RHAR in a wireless power transmitter system?

The BQ500511RHAR serves as the digital intelligence core of a two-chip wireless power transmitter, handling protocol compliance (WPC v1.2 A11), Foreign Object Detection, Dynamic Power Limiting, LED status indication, and closed-loop power regulation. It does not drive power MOSFETs directly - instead, it commands the bq50002 analog front end via PWM and MODE signals to control the full-bridge power stage. The BQ500511RHAR relies on external analog inputs (ISENSE, VSENSE, VPEAK, TSENSE) and communicates with receivers through COMM1/COMM2 channels derived from the bq50002.

How does the BQ500511RHAR implement Foreign Object Detection (FOD)?

The BQ500511RHAR implements FOD by continuously estimating unaccounted-for power loss using measured input current (ISENSE), input voltage (VSENSE), peak coil voltage (VPEAK), and receiver-reported power. Loss threshold is set via analog voltage on FOD_THR (Pin 35), with 1 V = 400 mW default. Load-dependent compensation is applied using FOD_CAL (Pin 10), enabling correction from –1000 to +1000 mW/A. This dual-resistor method allows empirical tuning to meet WPC v1.2 heating limits without requiring firmware updates - a key differentiator from fixed-threshold alternatives.

Can the BQ500511RHAR operate without the bq50002 analog front end?

No, the BQ500511RHAR cannot operate standalone. It is explicitly designed as the digital controller in a two-chip solution and requires the bq50002 analog front end to provide essential functions: full-bridge gate driving, COMM1/COMM2 analog demodulation, oscillator generation (CLK_IN), and analog signal conditioning. Pins like CLK_IN (Pin 21), COMM1 (Pin 22), COMM2 (Pin 23), and DRV_EN (Pin 37) are defined solely for interfacing with the bq50002. Attempting to use the BQ500511RHAR without bq50002 results in non-functional power transfer and undefined behavior.

What are the key design considerations for the LED interface on the BQ500511RHAR?

The BQ500511RHAR provides three dedicated LED sink outputs (LED_A, LED_B, LED_C) that each require a 1-kΩ series resistor to drive standard LEDs. LED behavior is selected at power-up via LED_MODE (Pin 34) using a resistor divider to 3 V - nine predefined schemes (e.g., 2-LED standby/fault, 3-LED charge-complete/FOD-warning) are supported. Brightness is tuned by adjusting individual resistor values, but total sink current must remain within device limits. The BUZZ pin (Pin 15) provides optional 400-ms, 4-kHz acoustic feedback for charge initiation - useful where visual indicators are insufficient.

How does Dynamic Power Limiting™ (DPL) function in the BQ500511RHAR?

Dynamic Power Limiting™ (DPL) in the BQ500511RHAR monitors input voltage droop and automatically reduces output power to prevent supply collapse - critical for operation from current-limited sources like USB ports. When active, DPL modifies the frequency/duty-cycle control signals sent to the bq50002, lowering delivered power while maintaining communication. The LED indication changes per the selected LED_MODE scheme to visually signal DPL engagement. Unlike open-loop current limiting, DPL responds dynamically to real-time supply conditions and resumes normal operation upon receiving a negative Control Error Packet (CEP) from the receiver - ensuring seamless interoperability with compliant devices.