High efficiency DC/DC converters step-down 5V rails to point-of-load

Nov 9, 2015 -- Intersil Corporation today announced five new highly integrated synchronous buck regulators that step-down 5V rails to point-of-load (POL) inputs as low as 0.6V for FPGAs, DSPs and microprocessors. The feature-rich 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 2mm 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 an innovative SYNCIN and SYNCOUT feature that connects and synchronizes 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 customers to leverage one design with smaller inductors for reduced costs and board area. In addition, the 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.

“As the number of voltage rails increases and design complexity continues to grow, power supply designers need switching regulators that deliver high efficiency, fast transient response and are simple to use,” said Mark Downing, senior vice president of Infrastructure and Industrial Power Products at Intersil. “The new 8A and 3A synchronous buck regulators give our customers the right set of features and flexibility in a compact solution size as small as 2 by 2mm required for point-of-load applications.”

Key Features and Specifications of ISL8018

• Delivers high peak efficiency up to 97%
• Complete converter occupies less than 97mm² of board space
• +/-10% output voltage margining
• Output voltage is adjustable from 0.6V to Vin, with a fixed output voltage option
• Adjustable current limit
• External synchronization up to 4MHz, with master-to-slave phase shifting capability
• Adjustable switching frequency from 500kHz to 4MHz, with default at 1MHz
• Start-up with pre-bias output, internal soft-start -- 1ms or adjustable, internal/external compensation
• Soft-stop output discharge during disabled
• Peak current limiting, hiccup mode short circuit protection and over-temperature protection

Key Features and Specifications of ISL80030, ISL80030A, ISL80031, ISL80031A

• Deliver high peak efficiency up to 95%, with 3A maximum output current
• Switching frequency up to 2MHz
• Provides quiescent current as low as 35uA
• Selectable PFM or PWM operation
• Short-circuit protection, and over-current, negative current, over-temperature/thermal protection
• Internal soft-start and soft-stop
• Vin under-voltage lockout and Vout over-voltage protection

These synchronous buck regulators can be combined with the ISL85033 dual 3A output synchronous buck regulator in POL applications, and the ISL85003 4.5V to 18V, 3A synchronous buck regulator for a two-stage solution converting a 12V rail to a 5V rail. The ISL85403 also can be used for a two-stage solution to step-down a 24V rail to a 5V rail.