Its synchronous rectification topology delivers up to 93% efficiency while Burst Mode operation keeps quiescent current under 30 µA (all channels) in no-load standby conditions, suiting it for always-on systems. For noise-sensitive applications, the LT8602 uses its pulse-skipping mode to minimise switching noise and meet the CISPR25, Class 5 EMI requirements. Switching frequency can be programmed from 250 kHz to 2.2 MHz and is synchronisable throughout this range.
The LT8602’s 60 nsec minimum on-time enables 16VIN to 0.8VOUT step-down conversions while switching at 2 MHz, enabling designers to avoid critical noise-sensitive frequency bands such as AM radio, while using a very compact solution footprint. Its 3V to 42V input voltage range suits it for automotive applications that 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 LT8602 maintains a minimum dropout voltage of 200 mV (at 1A) under all conditions, handling automotive cold-crank. Programmable power-on reset and power-good indicators for each channel ensure overall system reliability. The LT8602’s 40-lead thermally enhanced 6 x 6 mm QFN package and high switching frequency keep external inductors and capacitors small, providing a compact, thermally efficient footprint.
The LT8602 uses quad 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 and 3 switch 180° out of phase with channels 2 and 4 to reduce output ripple. Each channel has a separate input for added design flexibility, but most applications will run the two low voltage channels directly from the two high voltage channels to provide a very simple, high frequency quad output design. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15mVP-P. Efficiency is maintained over a wide input voltage range, and the LT8602’s current-mode topology enables fast transient response and good loop stability. Other features include internal compensation, power good flags, output soft-start/tracking, short-circuit and thermal protection.
The LT8602 is available in a thermally enhanced 40-lead 6 x 6 mm QFN package. Three temperature grades are available, with operation from –40°C to 125°C (junction) for the extended E- and industrial I-grades; pricing starts at $5.67 (1000).
Linear Technology; www.linear.com/product/LT8602
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