July 28, 2015 – Linear Technology Corporation announces the LT8602, a 42V input capable, high efficiency quad output synchronous monolithic step-down switching regulator. Its quad-channel design integrates two high voltage 2.5A and 1.5A channels with two lower voltage 1.8A channels to provide four independent outputs, with output voltages as low as 0.8V. The synchronous rectification topology delivers efficiency up to 93%, while Burst Mode® operation keeps quiescent current under 30µA (all channels) in no-load standby conditions, making it ideal for always-on systems. For noise-sensitive applications, the LT8602 utilizes a pulse-skipping mode to minimize switching noise and meet CISPR25, Class 5 EMI requirements. The switching frequency can be programmed over the range of 250 kHz to 2.2 MHz and can be synchronized throughout this range.

The LT8602's 60ns minimum on-time enables 16VIN to 0.8VOUT step-down conversions while switching at 2MHz, enabling designers to avoid noise-sensitive frequency bands such as AM radio while maintaining a very small solution footprint. Its 3V to 42V input voltage range makes it ideal for automotive applications which must handle cold-crank and stop-start scenarios with a minimum input voltage as low as 3V, as well as load dump transients exceeding 40V. Each channel of the LT8602 maintains a minimum dropout voltage of only 200mV (at 1A) under all conditions, enabling it to withstand scenarios such as automotive cold-crank. Programmable power-on reset and a power good indicator for each channel ensure overall system reliability. The LT8602's 40-lead thermally enhanced 6mm x 6mm QFN package and high switching frequency keep external inductors and capacitors small, providing a compact, thermally efficient footprint.

The LT8602 integrates the necessary boost diode, oscillator, control, and logic circuitry onto a single die, resulting in a quad-stage, high-efficiency power switch design. Channels 1 and 3 are 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 drive the two lower 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. Proprietary design techniques and a new high-speed process enable high efficiency over a wide input voltage range, and the LT8602's current-mode topology enables fast transient response and excellent loop stability. Other features include internal compensation, a power-good flag, output soft-start tracking, short-circuit protection, and thermal protection.

The LT8602 is available in a thermally enhanced 40-lead 6mm x 6mm QFN package. It is available in three temperature grades, with operation from –40°C to 125°C (junction) for the extended E-grade and industrial I-grade. Pricing starts at $5.35 each in 1,000-piece quantities. All versions are available from stock. For more information, see www.linear.com/product/LT8602.

42V, quad output 2.2MHz synchronous step-down DC/DC converter

Product Features: LT8602

· Highly flexible power supply system providing four outputs with a wide input range

· Two high-voltage synchronous buck regulators:

o 3V ~ 42V input voltage range

o Output current up to 2.5A and 1.5A

o High efficiency up to 93%

· Two low-voltage synchronous buck regulators:

o 2.6V ~ 5.5V input voltage range

· Output current up to 1.8A & 94% efficiency

· Programmable and synchronizable resistor: 250kHz to 2.2MHz switching frequency

· Low ripple Burst Mode® operation:

o 30μA IQ at 12VIN

o Output ripple less than 15mV

· Programmable power-on reset

· Power Good Indicator

· Two-phase clock to reduce input current ripple

· Provides a 40-pin 6mm × 6mm QFN package with enhanced thermal performance