POWER AND LINEAR IC SOLUTIONS

PWM Buck Regulators Feature Auto-Tracking and Sequencing

ON Semiconductor’s NCP312x family of dual-output Pulse Width Modulation (PWM) buck regulators offer advanced auto-tracking and sequencing capabilities that enable exact timing and control over both output channels.

Featuring integrated MOSFETs that deliver up to 3A output current with switching frequency up to 2.2MHz, the new devices are aimed at a variety of consumer applications including set-top-boxes, LCD-TVs and cable modems. Their auto-tracking and sequencing features enable exact timing and control over both output channels, eliminating the need for expensive external voltage-tracking controllers.



Today’s Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs) and other complex devices require multiple power supplies generating different voltage levels to power core logic, I/O and peripherals. Just as important, these voltages must be powered up and down under tight timing constraints. This timing control not only ensures correct operation, but also prevents latch-up conditions that can cause immediate or latent damage.

The NCP312x family of devices offers programmable ratiometric, sequential and tracking control to manage output voltage behaviour during start-up and power-down. Additionally, multiple NCP312x devices can be daisy-chained together to control multiple outputs. The outputs can also be paralleled to provide a dual-phase, single output regulator with low ripple voltage.

The 2A (NCP3120, NCP3122) and 3A (NCP3121, NCP3123) converters reduce input capacitance requirements by switching 180° out-of-phase. This allows the use of a single low-cost electrolytic or ceramic capacitor for the input filter.

With low shutdown current requirements (less than 100µA), the devices are suitable for use in power-constrained applications. Available in QFN-32 packaging, they feature cycle-by-cycle current limiting and UnderVoltage LockOut (UVLO).

Features

• 2A and 3A synchronous converters
• Programmable ratiometric, sequential and tracking control
• Daisy-chaining to control multiple outputs
• Output voltage range of +5V to +12V
• Adjustable 200kHz to 2.2MHz operation
• Stable with low-ESR ceramic output capacitor
• 0.8V ±1.5% reference voltage
• External soft-start
• Enable/disable capability
• Low shutdown power: less than 100µA
• UVLO
• QFN-32 package

Applications

• Set-top boxes
• LCD TVs
• Cable modems
• Consumer products

For further information, including Datasheets for the NCP3120/1/2 and 3, please click here