May 24, 2012 – Linear Technology Korea (CEO Hong Sa-kwak) announced the development of the LT8610, a synchronous step-down switching regulator capable of 2.5A output and 42V input. The product's synchronous rectification feature provides high efficiency of 96%, while its Burst Mode® operation mode is characterized by standby quiescent current consumption of less than 2.5µA under no-load conditions. The LT8610's input voltage range of 3.4V to 42V is ideal for automotive and industrial applications. The internal 3.5A switch can deliver continuous current up to 2.5A at a low voltage of 0.97V. The LT8610's Burst Mode operation, with its very low quiescent current consumption, is well-suited for applications such as automotive 'always-on' systems that require extended battery operating life.
The LT8610's unique design approach maintains a minimum dropout voltage of 200mV (@1A) under all conditions, providing excellent performance in scenarios such as automotive cold crank. Furthermore, the fast minimum on-time of 50ns enables 2MHz fixed-frequency switching over the input range of 16V to 1.8V output, allowing designers to optimize efficiency while avoiding frequency bands sensitive to noise. The LT8610, utilizing a thermally enhanced 16-pin MSOP package and high switching frequency, enables the use of smaller inductors and capacitors, providing a compact and thermally efficient footprint.
The LT8610 integrates internal top and bottom high-efficiency power switches and features an integrated boost diode, oscillator, control and logic circuitry on a single die. Low-ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 10mVPK-PK. Through specialized design techniques and new high-speed processes, high efficiency is achievable across a wide input voltage range, and the LT8610's current-mode topology provides fast transient response and excellent loop stability. Additional features include internal compensation, power good flag, output soft start/tracking, and thermal protection.
The LT8611 includes all features of the LT8610 along with monitor and control pins and a built-in current sense amplifier, providing accurate input or output current regulation and limiting functions. This product is offered in a 3mm × 5mm 24-pin QFN package.
The LT8610EMSE is available in a thermally enhanced MSOP-16 package at $3.55 per unit. The industrial temperature version LT8610IMSE is tested and guaranteed to operate at junction temperatures from -40°C to 125°C at $3.91 per unit. The automotive temperature version LT8610HMSE operates over a temperature range of -40°C to 150°C at $4.16 per unit. All prices are based on quantities of 1,000 units, and these versions are available for immediate purchase and use.
The LT8611EUDD is offered in a 3mm × 5mm QFN-24 package at $3.80 per unit. The industrial temperature version LT8611IUDD is tested and guaranteed to operate over a temperature range of -40°C to 125°C at $4.16 per unit. The automotive temperature version LT8611HUDD operates over a temperature range of -40°C to 150°C at $4.41 per unit. All prices are based on quantities of 1,000 units, and these versions are available for immediate purchase and use. For detailed product information, refer to www.linear.com/product/LT8610 and www.linear.com/product/LT8611.

Photo Caption: 42V, 2.5A (IOUT), 2.2MHz Synchronous Step-Down DC/DC Converter with IQ = 2.5µA

Product Features: LT8610/LT8611
• Wide input voltage range: 3.4V to 42V
• Ultra-low standby current Burst Mode operation: 2.5μA IQ regulating 12VIN to 3.3VOUT, output ripple < 10mVP-P
• High efficiency synchronous operation
o 96% efficiency @ 1A, 5VOUT from 12VIN
o 94% efficiency @ 1A, 3.3VOUT from 12VIN
• Fast minimum switch-on time: 50ns
• Low dropout voltage under all conditions: 200mV @ 1A
• Small inductor usable
• Adjustable and synchronizable: 200kHz to 2.2MHz
• Current mode operation
• Precise 1V enable pin threshold
• Internal compensation
• Output soft start and tracking
• Rail-to-rail current sense amplifier with monitor function (LT8611)
• Thermally enhanced compact 16-pin MSOP package (LT8610)
• Thermally enhanced compact 3mm × 5mm 24-pin QFN package (LT8611)