Intersil's high-efficiency, highly-integrated 8A and 3A synchronous buck regulators target point-of-load apps



Intersil's DC/DC converters step-down 5V rails to point-of-load

Intersil, a leading provider of innovative power management and precision analog solutions, 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.

Intersil's high efficiency DC/DC converters step-down 5V rails to point-of-load
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.

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 64mm2 of board space. And the ISL80031 and ISL80031A offer a light load mode to improve efficiency over all load currents when the system switches to a low power state.

"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.

Pricing and Availability
The ISL8018 8A synchronous buck regulator is available now in a 3mm x 4mm, 20-lead QFN package and is priced at $1.60 USD in 1k quantities. The ISL8018DEMO1Z demonstration board can be purchased for $20 USD each, and the full-featured ISL8018EVAL3Z evaluation board is $115 USD each. 

The ISL80030, ISL80030A, ISL80031 and ISL80031A 3A synchronous buck regulators are available now in 2mm x 2mm, 8-pin DFN packages. 1k unit pricing for the ISL80030 and ISL80030A is 0.59 USD each, and the ISL80031 and ISL80031A is $0.60 USD each. The ISL80030DEMO1Z and ISL80031DEMO1Z demonstration boards can be purchased for $18 USD each.