Step-down DC/DC converter delivers 93% efficiency

Burst Mode operation keeps quiescent current under 30µA (all channels) in no-load standby conditions, making the LT8601 suited for always-on systems. For noise sensitive applications, pulse-skipping mode minimises switching noise. The LT8601's switching frequency can be programmed from 250kHz to 2.2MHz and is synchronisable throughout this range.

The LT8601’s 60ns minimum on-time enables 16V_IN to 0.8V_OUT step-down conversions while switching at 2MHz, enabling designers to avoid critical noise-sensitive frequency bands, such as AM radio, while using a very compact solution footprint. Its 3 to 42V input voltage range is suited for automotive applications which must regulate through cold-crank and stop-start scenarios with minimum input voltages as low as 3V and load dump transients in excess of 40V. Each channel of the LT8601 maintains a minimum dropout voltage of only 250mV at 1A under all conditions, enabling it to excel in scenarios such as automotive cold-crank. Programmable power-on reset and power good indicators for each channel ensure overall system reliability.

The LT8601 utilises triple internal top and bottom high efficiency power switches with the necessary boost diodes, oscillator, control and logic circuitry integrated into a single die. Channel 1 switches 180° out-of-phase with channels 2 and 3 to reduce output ripple. Each channel has a separate input for added design flexibility, but most applications will run the low voltage channel directly from one of the two high voltage channels to offer a very simple, high frequency triple output design. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15mV_P-P. Unique design techniques and a new high speed process enable high efficiency over a wide input voltage range while the LT8601’s current mode topology enables fast transient response and excellent loop stability. Other features include internal compensation, power good flags, output soft-start/tracking, short-circuit and thermal protection. The converter meets the CISPR25, Class 5 EMI requirements.

The LT8601 is available in a thermally enhanced 40-lead 6x6mm QFN package. Two temperature grades are available, with operation from -40 to +125°C junction for the extended E and industrial I grades. The industrial grade’s electrical parameters are guaranteed throughout the temperature range. 1,000 unit pricing starts at $5.15 each with all versions are available from stock.