April 2, 2012 – Linear Technology Korea (CEO Hong Sa-kwak) announced the development of a monolithic, dual-output step-down switching regulator (product name: LT3992) capable of supplying up to 3A of continuous output current from each channel. Operating over an input voltage range of 3V to 60V, this product is ideal for automotive applications requiring continuous output voltage regulation during load dump and cold crank conditions. Individual input, shutdown, feedback, soft-start, current limit, and comparator pins for each channel simplify complex power supply tracking and sequencing requirements. The LT3992's switching frequency is user-programmable from 250kHz to 2.25MHz, allowing designers to optimize efficiency while avoiding demanding, noise-sensitive frequency bands.
To optimize efficiency and component size, the two internal converters feature programmable maximum current limiting capabilities and can be synchronized via the LT3992's internal oscillator or an external clock input. These converters are capable of 180° out of phase, further reducing voltage ripple and external component size. Multiple regulators can be synchronized via an external clock output to provide additional voltage rails. These outputs can also be combined for high-current applications, and the LT3992 can provide a continuous output current of up to 6A. The device offers a compact and highly thermally efficient footprint by enabling the use of ultra-small external capacitors and inductors in 5mm x 5mm QFN-32 or heat-enhanced TSSOP-38 packages, along with high switching frequency characteristics. The LT3992's main switcher utilizes a high-efficiency 3.5A, 325mVCESAT switch, and the control and logic circuits, including the essential oscillator, are integrated on a single die.
This device enables high efficiency over a wide input voltage range through unique design technology, and provides fast transient response and excellent loop stability via the application of a current-mode topology. The LT3992 features a frequency divider on one channel, allowing it to operate at 1/2, 1/4, or 1/8 the frequency of the other channel, while offering high step-down ratios and minimizing external component size. Furthermore, protection capabilities have been further enhanced through improved short-circuit protection and die temperature monitoring. Other features include thermal shutdown and an independent power good flag.
The LT3992EUH is available in a 5mm x 5mm 32-pin QFN package, while the LT3992EFE is available in a thermally enhanced FMEA-tolerant TSSOP-38 package. Both are priced at $4.65 and $5.05, respectively. The industrial-grade versions, the LT3992IUH and LT3992IFE, are both tested and guaranteed to operate over a temperature range of -40°C to 125°C, priced at $5.12 and $5.56, respectively. The high-temperature grade LT3992HFE is tested and guaranteed to operate over a temperature range of -40°C to 150°C, priced at $5.81 per unit. All prices are based on a quantity of 1,000 units, and all versions of the LT3992 are available for immediate purchase. For more information, please visit www.linear.com/product/LT3992 .

Photo Caption: 60V, Dual 3A (IOUT), Step-down DC/DC Converter

Product Features: LT3992

• Wide input voltage range: Operates from 3V to 60V
• Individual supply, shutdown, soft start, UVLO, programmable current limiting for each 3A regulator, and programmable power good
• Die temperature monitor
• Adjustable/synchronizable fixed frequency operation in the 250kHz to 2.25MHz range with synchronized clock output
• Optimize component size with individual synchronized switching frequencies
• Anti-face switching
• Output can be connected in parallel
• Flexible output voltage tracking
• Low Dropout: 95% Max Duty Cycle
• 5mm x 5mm QFN package
• FMEA compatible 38-pin exposed pad TSSOP package