Linear Technology Korea announced the launch of the LT8641, a synchronous step-down switching regulator capable of 3.5A output current and 65V input. The proprietary Silent Switcher® architecture, combined with wide-spectral frequency modulation capabilities, reduces EMI/EMC emissions by more than 25dB even at switching frequencies exceeding 2MHz. This enables it to easily pass the peak and average limits of the automotive CISPR25 class 5. Synchronous rectification provides high efficiency of 94% at a switching frequency of 2MHz. The product's 3V to 65V input voltage range makes it ideal for single or dual-cell automotive, transportation, and industrial applications.

The LT8641's internal high-efficiency switch provides a continuous output current of up to 3.5A and a peak current of 5A at a low voltage of 0.81V. The device's Burst Mode® operation is well-suited for applications such as automotive “always-on” systems that need to extend battery life by maintaining a standby current of 2.5µA or less under no-load standby conditions.



The LT8641's proprietary design maintains a minimum dropout voltage of only 130mV at 1A under all conditions, enabling outstanding performance in scenarios such as automotive cold cranking. Furthermore, a fast minimum on-time of just 35ns enables 2MHz constant-frequency switching from 24V input to 3.3V output, allowing designers to optimize efficiency while avoiding critical noise-sensitive frequency bands. The LT8641's 18-pin 3mm x 4mm QFN package and high switching frequency keep external inductors and capacitors small, providing a compact yet thermally efficient footprint.


The LT8641 utilizes an integrated, high-efficiency upper and lower power switch that combines essential boost diodes, oscillators, control, and logic circuitry onto a single die. The low-ripple burst mode maintains output ripple of less than 10 mVP-P while preserving high efficiency at low output currents. Specific design techniques and a new high-speed process enable high efficiency across a wide input-output range, while the LT8641's current-mode topology delivers fast transient response and excellent loop stability. Other features include internal compensation, a power good flag, output soft-start/tracking, and thermal shutdown.

The LT8641EUDC is available in a 3mm x 4mm QFN package. The industrial temperature version, the LT8641IUDC, has been tested and guarantees operation over operating junction temperatures ranging from –40°C to 125°C. Priced at $4.35 per unit in 1,000-unit quantities, both versions are available immediately. For more information, visit www.linear.com/product/LT8641.