New Industry Products

# 95% Efficient 2A and 3A Synchronous Buck Regulators in DFN3x3 Exposed Pad Package

February 07, 2019 by Scott McMahan

Alpha and Omega Semiconductor Limited introduced AOZ6662DI-01 and AOZ6663DI-01, high-efficiency, synchronous buck regulators. The AOZ6662DI-01 and AOZ6663DI-01 are both available in a thermally enhanced DFN3x3 exposed pad package, delivering an output current of 2A and 3A, respectively.

The new devices provide a low on-resistant power stage, enabling cooler power conversion for a variety of consumer electronics application such as LCD TVs, set-top boxes, as well as DVD players and recorders.

"Today's consumer electronics products are built with features that require flexibility to meet a broad range of applications. Design engineers are looking for dc-dc converters that offer high light load efficiency at specific voltage ranges"

The low on-resistance of the internal power MOSFETs in these regulators allows higher efficiency and produces less heat. At full load operation, they have over 90 percent efficiency and maintain 87 percent efficiency while in 10mA light load operation. When operating in low output current conditions, the buck regulators will run in a proprietary pulse energy mode (PEM) to achieve high efficiency. Under heavy-load, steady-state conditions, the device will operate in a fixed frequency and Continuous-Conduction Mode (CCM).

The small standby current combined with a thermally enhanced package obtains enhanced efficiency and thermal performance compared to the leading competitor's previous generation solution.

"Today's consumer electronics products are built with features that require flexibility to meet a broad range of applications. Design engineers are looking for dc-dc converters that offer high light load efficiency at specific voltage ranges," said Kenny Hu, Power IC Marketing Manager at AOS. "The AOZ6662DI-01 and AOZ6663DI-01 meet these design challenges with adaptable light load capability."

The AOZ6663DI-01 has an input range from 4.5V to 18V and features a feedback tolerance of ±1.5% compared. The AOZ6663DI-01 has an exposed-pad DFN3x3 package. At a light load of 10mA with a Vin of 2V and Vout of 5V, the device achieves 87.1% efficiency.

The thermal characteristics are where the new device far exceeds the performance of the competition with a thermal impedance of just 50°C/W compared to a much higher 93°C/W for the competitor. And operating with an output of (3A) at 15W, the device has a temperature of 84°C compared to a significantly higher 121°C for the competition.

The buck regulators have a maximum load current of 2A or 3A depending on the model, and have a minimum Vout of 0.6V or 0.8V. The devices operate at a frequency of either 550kHz or 750kHz and have a quiescent current of 550µA or 250µA respectively. The AOZ6662DI-01 has a synchronous buck of 145mΩ internal high-side switch and 90mΩ Internal low-side switch and features a 2A continuous output current. The AOZ6663DI-01 has a synchronous buck of 145mΩ internal high-side switch and 80mΩ Internal low-side switch and features a 3A continuous output current.

#### Features for both AOZ6662DI-01 and AOZ6663DI-01

• 4.5V to 18V operating input voltage range
• Up to 95% efficiency
• Pulse Energy Mode for light load efficiency. (Vin=12V, Vout=5V, 87%@10mA)
• Output voltage adjustable to 0.6V
• 750kHz PWM operation
• External compensation
• Internal Soft Start
• Cycle-by-cycle current limit
• Pre-bias start-up
• Short-circuit protection
• Thermal shutdown

The AOZ6662DI-01 and the AOZ6663DI-01 are immediately available in production quantities with a lead-time of 12 weeks. The unit price for 1,000 pieces is $0.42 for the AOZ6662DI-01 and$0.52 for the AOZ6663DI-01.