New Industry Products

ON Semi Introduces New Family Of PWM Buck Regulators

March 10, 2008 by Jeff Shepard

ON Semiconductor introduced the NCP312x family of dual output pulse width modulation (PWM) buck regulators that are said to offer unique auto-tracking and sequencing capabilities. Featuring integrated MOSFETs that deliver 2A (NCP3120, NCP3122) or 3A (NCP3121, NCP3123) output current with switching frequency up to 2.2MHz, the new devices are suitable for a variety of consumer applications including set-top-boxes (STB), LCD-TVs and cable modems.

"One of the biggest challenges facing power supply design engineers is the power-up and power-down timing requirements for multi-voltage systems," said Tim Kaske, ON Semiconductor Product Line Marketing Manager for the Power Regulation Product Group. "ON Semiconductor offers a solution to help ease this design challenge with the new NCP312x family of switching regulators. These new regulators eliminate the need to use expensive voltage tracking controllers with a unique built-in auto tracking and sequencing capability."

The auto-tracking and sequencing features of the NCP312x devices enables exact timing and control over both output channels. A Digital Signal Processor (DSP), Field Programmable Gate Array (FPGA) or other signal processor requires multiple power supplies generating different voltage levels for core and Input/Output (I/O) peripherals and specific timing of each voltage. This timing control prevents latchup conditions that can cause immediate damage or even latent damage that produces failures in the field. The NCP312x family of devices offers programmable ratiometric, sequential and tracking control to manage the output voltage behavior during start-up and power-down. Additionally, multiple NCP312x devices can also be daisy chained together to control multiple outputs.

NCP312x converters reduce input capacitance requirements by switching 180 degrees out-of-phase at a frequency of 200KHz up to 2.2MHz. The out-of-phase operation allows the use of a single low cost electrolytic capacitor or ceramic capacitor for the input filter versus two capacitors in a standard configuration. The outputs can also be paralleled to provide a dual-phase, single output regulator with low ripple voltage.

The NCP3120, NCP3121, NCP3122, and NCP3123 are available in a QFN-32 package with budgetary price from $1.30- $1.55 USD per unit in 1,000 unit quantities.