Dual (2.5A + 1.5A) Synchronous Step-Down DC/DC Converter Delivers 95% Efficiency & Operates from 3.4V to 42V Inputs

May 12 2015 - MILPITAS, CA
  • Linear Technology Corporation announces the LT8616, a 42V input capable, high efficiency dual synchronous monolithic step-down switching regulator. Its dual channel design delivers independent 2.5A and 1.5A continuous current to outputs as low as 0.8V. A dual channel synchronous rectification topology delivers up to 95% efficiency while Burst Mode® operation keeps quiescent current under 6.5µA (both channels enabled) in no-load standby conditions, making it ideal for always-on systems. Switching frequency can be programmed from 200kHz to 3MHz and is synchronizable throughout this range.

    42V, Dual Output 3MHz Synchronous Step-Down DC/DC Converter


    The LT8616’s 35ns minimum on-time enables 16VIN to 1.8VOUT step-down conversions, while switching at 2MHz helps designers avoid critical noise-sensitive frequency bands, such as AM radio while having a very compact solution footprint. Its 3.4V to 42V 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 3.4V and load dump transients in excess of 40V. Each channel of the LT8616 maintains a minimum dropout voltage of only 400mV (at1A) 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 15mVP-P. 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.

    The LT8616 is available in a thermally enhanced 28-lead TSSOP package. Three temperature grades are available, with operation from –40°C to 125°C (junction) for the extended (E) and industrial (I) grades and a high temperature (H) grade of –40°C to 150°C. The 1,000 piece price starts at $4.15. All versions are available from stock. For more information, visit www.linear.com/product/lt8616.

    Summary of Features: LT8616

    • Wide Input Voltage Range: 3.4V to 42V
    • 2.5A and 1.5A Buck Regulators with Separate Inputs
    • Fast Minimum Switch On-Time: 35ns
    • Ultralow Quiescent Current Burst Mode® Operation:
      • 6.5µA IQ Regulating 12VIN to 5VOUT and 3.3VOUT
      • Output Ripple < 15mV
    • 180° Out-of-Phase Switching
    • Adjustable and Synchronizable: 200kHz to 3MHz
    • Accurate 1V Enable Pin Thresholds
    • Internal Compensation
    • Output Soft-Start and Tracking
    • TSSOP Package: Output Stays at or Below Regulation Voltage During Adjacent Pin Short or When a Pin Is Left Floating
    • Thermally Enhanced 28-Lead TSSOP Package



    The USA list pricing shown is for budgetary use only. International prices may differ due to local duties, taxes, fees and exchange rates.

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