Reduces EMI/EMC emissions with copper pattern design
Suitable for applications with long battery life

Analog Devices announced the release of the new LT8640S synchronous step-down switching regulator, which supports 6A, 42V input.

This product features the Silent Switcher® 2 architecture. It is characterized by the use of internal BST and INTVCC capacitors to minimize hot loop area, including two internal input capacitors.

The LT8640S significantly reduces EMI/EMC emissions by adopting a design that utilizes stabilized switching edges, internal circuits coupled to the ground plane, and copper pillars instead of bonding wires. Thanks to this enhanced EMI/EMC performance, it is less affected by board layout, which not only simplifies the design but also reduces risk when using 2-layer PC boards. The LT8640S operates at a switching frequency of 2 MHz across the entire load range, easily passing automotive CISPR 25, Class 5 peak EMI standards. EMI/EMC can also be further reduced through spread-spectrum frequency modulation.



The LT8640S's synchronous rectification provides a high efficiency of 95% when operating at a switching frequency of 2 MHz. It supports a wide input voltage range of 3.4 V to 42 V, making it suitable for automotive and industrial applications. The built-in high-efficiency switch provides a continuous output current of up to 6A and a peak load of 7A for a low voltage of 0.97V.

The Burst Mode® operation of the LT8640S consumes only 2.5µA of standby current, making it ideal for applications requiring long battery life, such as automotive always-on systems.

The LT8640S's unique design maintains an extremely low dropout voltage of 100mV (at 1A) under any conditions, enabling exceptional performance in situations such as automotive cold-crank. Furthermore, with a minimum on-time of just 30ns, it allows for constant frequency switching at 2MHz from a 16V input to a 1.5V output, enabling designers to optimize efficiency and avoid noise-sensitive critical frequency bands. The LT8640S's 24-pin, 4mm x 4mm LQFN package and high switching frequency provide a compact and thermally efficient footprint by allowing the use of small external inductors and capacitors.

The LT8640S utilizes internal high-efficiency power switches at the top and bottom, along with essential boost diodes, oscillators, control, and logic circuits integrated on a single die. Low-ripple burst mode operation maintains high efficiency at low output currents and keeps output ripple below 10 mVP-P. For applications requiring very low-noise operation, the LT8640S can be configured to operate in forced continuous mode across the entire load range.


The switching frequency can be programmed and synchronized in the range of 200kHz to 3MHz. Special design techniques and a new high-speed process are applied to provide high efficiency over a wide input voltage range, and the LT8640S's current mode topology ensures fast transient response and excellent loop stability. In addition, it includes features such as internal compensation, a power good flag, output soft-start/tracking, and overtemperature protection.