High-integration 8 &3A synchronous regulators with phased slaving

November 11, 2015 // By Graham Prophet
Five high efficiency DC/DC converters step-down 5V rails to point-of-load (POL) rails as low as 0.6V for FPGAs, DSPs and microprocessors. ISL8018 delivers up to 8A of continuous output current from a 2.7V to 5.5V input supply, while offering up to 97% efficiency and higher integration than competitive devices.

The 2 x 2 mm ISL8003x family of devices delivers up to 3A of continuous output current from a 2.7V to 5.5V input supply and offers up to 95% peak efficiency for delivering general POL conversions in telecom, cloud computing, industrial, instrumentation and medical equipment.

The ISL8018 provides a SYNCIN and SYNCOUT feature that connects and synchronises multiple regulators at the same switching frequency in a master/slave configuration using a phase shifting time delay. This prevents ON time overlapping and reduces RMS current, ripple and input capacitance requirements to improve EMI and efficiency. With the ISL8018’s VSET feature, the voltage output margining can be set at ±10% to compensate for output voltage IR drop. The ISET feature provides programmable output current limits to support 8A, 5A and 3A applications. This allows designers to make the most of one design with smaller inductors for reduced costs and board area. ISL8018’s programmable switching frequency from 500 kHz up to 4MHz enables the use of smaller passive components for faster transient response and further board space savings.

The ISL80030, ISL80030A, ISL80031, and ISL80031A are pin-compatible and integrate very low RDS(ON) high-side PMOS and low-side NMOS MOSFETs, which reduces external component count and power losses. With lower die temperatures, these buck regulators allow the system to operate without cooling fans or heatsinks and still deliver a continuous 3A to the load, significantly increasing reliability. They also offer internal compensation, which eliminates additional external components to reduce design complexity. The complete converter occupies less than 64 mm² of board space. ISL80031 and ISL80031A offer a light load mode to improve efficiency over all load currents when the system switches to a low power state.

The ISL8018 8A synchronous buck regulator is available in a 3 x 4 mm, 20-lead QFN package and is priced at $1.60 (1000). The ISL8018DEMO1Z demonstration board is $20 and the full-featured ISL8018EVAL3Z evaluation board is $115.

Intersil; www.intersil.com/products/isl8018

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