Date: 30/07/2009

Semtech's new SC414/SC424 6A, 28V synchronous buck regulators with 5V LDO

Semtech's SC414 and SC424 are 6A, 28V synchronous buck regulators featuring with integrated power MOSFETs, a bootstrap switch, and a 5V LDO.

The 5V LDO is used to provide the bias voltage for the gate drive circuitry or for optimum efficiency; the internal crossover circuitry bypasses the LDO after startup, if the LDO and buck outputs are the same.

The buck controller uses a pseudo-fixed frequency adaptive on-time operation to provide fast transient response, which permits the use of smaller output capacitors.
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Key features are,

Operating voltage from 3V to 28V
Integrated 5V, 150mA LDO with bypass capability
Independent enable for switcher and LDO
Selectable ultrasonic power-save (SC414)
Selectable power-save (SC424)
1% of tolerance
Power good output
SmartDrive

SC414/SC424 also features built-in soft-start, cycle-by-cycle current limiting, over-temperature, and over- and under- voltage protection, soft shutdown, and selectable power-save. The device also provides separate enable inputs for the PWM controller and LDO as well as a power good output for the PWM controller.

The input voltage range, programmable frequency, and 5V LDO make the device flexible and easy to use in a broad range of applications. Support is provided for single cell or multi-cell battery systems in addition to traditional DC power supply applications.

SC414/SC424 applications are,

Notebook, desktop, tablet, and server computers
Networking and telecommunication equipment
Printers, DSL, and STB applications
Embedded computer applications
Power supply modules

Semtech's Smart Power Save technique enables these devices to re-enter continuous conduction mode when active loads try to pull the output high while in power save mode, pulling the output back down and avoiding over voltage latch-off.

Like the SC417 and SC427, the SC414 and SC424 also feature temperature compensated RDS (ON) sensed current limit, which effectively doubles the current limit precision.

"The SC414 and SC424 6A buck regulators complement the SC417 and SC427 very nicely, adding a smaller solution for lower current point-of-load applications with the same flexibility and ease of use that are already so popular. Having pin-to-pin compatible ultrasonic and regular power save versions makes it simple to change designs downstream as requirements change," said Alan Burchfield, Senior Product Marketing Manager for Semtech's Power Management Group. "The wide input operating range, single input rail capability, and compact package, along with high efficiency over the entire load range make them broadly applicable to applications such as ultra mobile, industrial and notebook PCs, wireless base stations, multi-function printers, and digital TV."

Package: Lead-free 4x4mm, 28 Pin MLPQ package
Price: Each $1.97 for 3k pieces
Availability: Now

For more information, visit www.semtech.com.