42V, 3.5A-out buck regulator operates at 175°C ambient

June 02, 2016 // By Graham Prophet
LT8610AX is a 3.5A, 42V input-capable synchronous step-down switching regulator, which operates in ambient temperatures up to 175°C. Synchronous rectification delivers efficiency as high as 95% while Burst Mode operation keeps quiescent current under 3.5 µA in no-load standby conditions.

The device’s 3.7V to 42V input voltage range is suitable for high temperature applications such as down-hole drilling equipment with power sources ranging from 5V to 40V. The LT8610AX’s electrical parameters are 100% tested at 175°C, offering a VREF accuracy of 2% over the entire -40°C to 175°C temperature range. At ambient temperatures of 175°C, the LT8610AX offers over 90% efficiency (for 12 VIN to 3.3 VOUT conversions) over a load current range of 10 mA to 1A, for battery powered applications commonly found in down-hole drilling systems. The LT8610AX’s Burst Mode operation offers ultralow quiescent current, suited for applications requiring extended operating battery life. The LT8610AX’s 16-lead thermally enhanced MSOP package provides a compact, thermally efficient footprint.


The LT8610AX employs internal top and bottom high efficiency power switches with the necessary boost diode, oscillator, control and logic circuitry integrated into a single die. This eliminates the need for any external Schottky diodes, which can be problematic at high temperatures. The LT8610AX’s lack of thermal shutdown is ideal for high temperature environments. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 10 mVP-P. The LT8610AX’s current mode topology enables fast transient response and excellent loop stability. Specialized Cu/Ni/Au bond pad plating ensures long life in high temperature environments. Other features include internal compensation, a power-good flag and output soft-start/tracking.


The LT8610AXMSE is packaged in a thermally enhanced MSOP-16 package, for $125.00 each (1,000).


Linear Technology; www.linear.com/product/LT8610AX


next page; feature listing;