LT8620 Series Regulator

By Analog Devices Inc 88

LT8620 Series Regulator

Linear Technology's LT8620 is a 2 A, 65 V input capable synchronous step-down switching regulator. Synchronous rectification offers efficiency as high as 95% while Burst Mode® operation keeps quiescent current under 2.5 µA in no-load standby conditions. Its 3.4 V to 65 V input voltage range makes it ideal for automotive (single and dual battery) and industrial applications. Its internal high-efficiency switches can deliver up to 2 A of continuous output current to voltages as low as 0.97 V. The LT8620's Burst Mode operation offers ultralow quiescent current, making it well suited for applications such as automotive "always-on" systems, which need to extend operating battery life. The LT8620's design maintains a minimum dropout voltage of only 250 mV at 1 A under all conditions, enabling it to excel in scenarios such as automotive cold-crank.

The fast minimum on-time of only 30 ns enables 2 MHz constant frequency switching from a 16 V input to a 1.5 V output, enabling designers to optimize efficiency while avoiding critical noise-sensitive frequency bands. It's 24-lead 3 mm x 4 mm QFN or thermally-enhanced MSOP-16E package and a high switching frequency keeps external inductors and capacitors small, providing a compact, thermally efficient footprint.

The LT8620 integrates internal top and bottom high-efficiency power switches with the necessary boost diode, oscillator, control and logic circuitry integrated into a single die. Low-ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 10 mVPK-PK. Special design techniques and high-speed process enable high-efficiency over a wide input voltage range, and the LT8620's current-mode topology enables fast transient response and excellent loop stability.

Features and Benefits
  • Wide input voltage range: 3.4 V to 65 V
  • Ultralow quiescent current Burst Mode operation: 2.5 μA IQ regulating 12 VIN to 3.3 VOUT output ripple < 10mVP-P
  • High-efficiency synchronous operation: 94% efficiency at 1 A, 12 VIN to 5 VOUT and 92% efficiency at 1 A, 12 VIN to 3.3 VOUT
  • Fast 30 ns minimum switch-on time
  • Low dropout under all conditions: 250 mV at 1 A safely tolerates inductor saturation in overload
  • Low EMI
  • Adjustable and synchronizable: 200 kHz to 2.2 MHz
  • Accurate 1 V enable pin threshold
  • Internal compensation
  • Output soft-start and tracking
  • Small thermally-enhanced 24-lead 3 mm × 5 mm QFN package
  • Automotive and industrial supplies
  • General purpose step-down
  • GSM power supplies