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AnalogicTech Introduces Low-Power Load Switch For Biometric Devices

AAT4702 integrated load switch protects notebook and smartphone applications
SANTA CLARA, Calif., Sept. 8 /PRNewswire-FirstCall/ -- Advanced Analogic Technologies, Inc. (Nasdaq: AATI), an analog semiconductor company focused on powering innovative solutions in consumer, industrial, and telecom markets, introduced the AAT4702, a highly integrated load switch that requires half the board footprint of discrete alternatives. In addition to its small size, the AAT4702 consumes a 15 micro-A quiescent current, far less than any other integrated load switch/low-dropout (LDO) regulator on the market.

Packaged in a compact 8-pin, 2x2-mm FTDFN package, the AAT4702 is a current-limited P-channel metal-oxide-semiconductor field-effect transistor (MOSFET) power switch with an integrated LDO regulator that offers a variety of protection features including auto restart, reverse current blocking and a fault flag to deliver the highest available level of load current protection in a load switch.

"A growing number of applications, such as fingerprint sensing circuits, require both a system power supply and load current protection. The AAT4702 does both," said CJ Zhang, product line vice president. "By integrating a current limited load switch and an LDO in a single compact IC that requires minimal power resources, our new load switch gives notebook and mobile device designers an opportunity to support these applications in a much smaller, lower power circuit."

A member of AnalogicTech's Application Specific Power MOSFET (ASPM) product family, the AAT4702's load switch current limit is set at 150 mA as a default, but it is programmable up to 1A via an external set resistor. To further protect system loads or peripheral circuits from over-current conditions, the new load switch adds an auto-restart function that wakes up and re-enables the device every 40 ms to check for the continued existence of an over-current condition. If the over-current condition remains, the AAT4702 stays in shutdown mode with both the load switch and LDO regulator output pulled low to ground. This allows the device to automatically resume operation once the over-current condition ends, eliminating the risk of damage.

An integrated FAULT flag feature that indicates an over-current or over-temperature condition is also available, adding a 5 ms blanking time to prevent reports of false events. The AAT4702 also adds reverse current blocking to protect the load switch from reverse current potentials when the device is shut down. The integrated load switch/LDO operates from inputs ranging from 2.4V to 5.5V.

The LDO integrated into the AAT4702 delivers a regulated 1.8V supply voltage with plus or minus 2 percent accuracy at load levels up to 100 mA. It may be powered either directly from an input source supply or via the load switch output. Quiescent current for the AAT4702 is 15 micro A typical, by far the lowest specification in the industry for integrated solutions of this type. Shutdown current is less than 1 micro A. The single-chip solution offers up to a 50 percent board space savings compared to comparable discrete solutions.

Price and Availability

Qualified across the -40 C to +85 C temperature range, the AAT4702 is available in a compact 8-pin, 2x2-mm FTDFN package and is priced at $0.59 in 1K quantities.

More information: http://www.analogictech.com/products/product_part.php?PID=175

About Advanced Analogic Technologies, Inc.:

Advanced Analogic Technologies (NASDAQ: AATI) develops advanced semiconductor system solutions that play a key role in the continuing evolution of feature-rich, energy efficient electronic devices. The company focuses on addressing the application-specific power management needs of consumer devices such as mobile handsets, digital cameras, and netbooks/notebooks, as well as devices in a broad range of industrial, medical and telecom applications. AATI also licenses device, process, package, and application-related technologies. Headquartered in Silicon Valley, AATI has design centers in Santa Clara and Shanghai, and Asia-based operations and logistics. For more information, please visit www.analogictech.com (AnalogicTech - G).