Linear's latest synchronous step-down regulator operates to 175°C



The LT8610AX 3.5A, 42V input capable synchronous step-down switching regulator

Linear Technology announced the LT8610AX, 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 3.5µA in no-load standby conditions. Its 3.7V to 42V input voltage range is ideal 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 12VIN to 3.3VOUT conversions) over a wide load current range of 10mA to 1A, ideal for battery powered applications commonly found in down-hole drilling systems. The LT8610AX’s Burst Mode operation offers ultralow quiescent current, well 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 utilizes 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 10mVP-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, priced at $125.00 each in 1,000-piece quantities and available from stock. 

Summary of Features: LT8610AX
100% Tested at 175°C
±2% Reference Accuracy Over -40°C to 175°C Range
Wide Input Voltage Range: 3.7V to 42V
Ultralow Quiescent Current Burst Mode® Operation: 3.5µA
High Efficiency Synchronous Operation
91% Efficiency at 0.5A, at 175°C, 3.3VOUT from 12VIN
92% Efficiency at 0.5A, at 175°C, 5VOUT from 12VIN
Adjustable & Synchronizable Frequency: 200kHz to 2.2MHz
No Thermal Shutdown
Internal Compensation
Output Soft-Start & Tracking
Power Good Flag
Small Thermally Enhanced 16-Lead MSOP Package


Linear Technology