LT8616 Step-Down Regulator

The Analog Devices LT8616 is a 42 V input-capable, high-efficiency, dual-synchronous, monolithic, step-down switching regulator. Its dual-channel design delivers independent 2.5 A and 1.5 A continuous current to outputs as low as 0.8 V. A dual-channel synchronous rectification topology delivers up to 95% efficiency, while Burst Mode® operation keeps quiescent current under 6.5 µA (both channels enabled) in no-load standby conditions, making it ideal for always-on systems. Switching frequency can be programmed from 200 kHz to 3 MHz and is synchronizable throughout this range.

The LT8616’s 35 ns minimum on-time enables 16 V_IN to 1.8 V_OUT step-down conversions, while switching at 2 MHz helps designers avoid critical noise-sensitive frequency bands, such as AM radio, while having a very compact solution footprint. Its 3.4 V to 42 V input voltage range makes it ideal for automotive applications which must regulate through cold-crank and stop-start scenarios with minimum input voltages as low as 3.4 V and load dump transients in excess of 40 V. Each channel of the LT8616 maintains a minimum dropout voltage of only 400 mV (at 1 A) under all conditions, enabling it to excel in scenarios such as automotive cold-crank. The LT8616’s 28-lead thermally-enhanced TSSOP package and high switching frequency keeps external inductors and capacitors small, providing a compact, thermally-efficient footprint.

The LT8616 utilizes dual internal top and bottom high-efficiency power switches with the necessary boost diodes, oscillator, control, and logic circuitry integrated into a single die. Each channel switches 180 degrees out-of-phase to reduce output ripple. Each channel has a separate input for added design flexibility. Low-ripple Burst Mode operation maintains high-efficiency at low-output currents while keeping output ripple below 15 mV_pp. Unique design techniques and a new high-speed process enable high efficiency over a wide input voltage range, and the LT8616’s current-mode topology provides fast transient response and excellent loop stability. Other features include internal compensation, power good flags, output soft-start/tracking, and thermal protection.