STMicroelectronics Adds PWM Controllers for Motherboard Applications to Power Management Portfolio
November 8, 2007 // Published as a news service by IHS
| |
| IHS Parts Solutions |
| Source parts, manage obsolescence, comply with regulations and speed time-to-market. For more information and a price quote, please complete the form below. |
|
STMicroelectronics (ST) extended its portfolio of power management devices with a new family of pulse width modulation (PWM) controllers intended for motherboard and point of load (POL) markets.
Four new products - L6726A, L6727, L6728 and L6728A - integrate a voltage reference, control logic, gate drivers, monitoring and protection circuits into standard SO-8 or tiny 3 millimeter x 3 millimeter dual flat no-lead (DFN) packages.
Two of the chips offer additional features for high-level applications, including a PowerGOOD output to report power status and the output voltage sense for accurate overvoltage and undervoltage protection.
The L6726A and L6727 are low-cost single-phase PWM controllers, with embedded high-current drivers, enabling the creation of general-purpose direct current to direct current (DC/DC) step-down converters for a range of applications - from desktop PC subsystems, such as memories and chipsets, to general-purpose power supplies.
The L6728 and L6728A add to the simpler devices the characteristics required by the high-end motherboard market, including plus or minus 0.8% voltage accuracy over line and temperature variations, a PowerGOOD output to provide real-time information on output-voltage status and the chip-scale 10-lead DFN package.
They offer a fixed-frequency 300 kHz (L6728) or 600 kHz (L6728A) oscillator. It is the first time that all of these features have been integrated into such a small package, ST said. The devices can be used in servers and nonisolated POL (niPOL) applications.
In addition to use on server and PC motherboards, the controllers can be used for modems, set-top boxes (STBs), consumer applications and advanced DC/DC down-converters.
With embedded high-current, high-speed N-channel metal-oxide semiconductor field-effect transistor (MOSFET) drivers, the chips can be used in the design of power applications driving a few amps (A) to more than 30 A. They operate over an input voltage range of 1.5 volts (V) to 18 V, while the integrated 0.8V voltage reference ensures 1% (L6726A, L6727) or up to 0.8% (L6728, L6728A) output accuracy.
Sensorless current monitoring, through a low-side power MOSFET, avoids the cost of an external current-sensing resistor and saves board space, and the single- or dual-level overcurrent protection has programmable thresholds.
The L6726A and L6727 are in volume production now and are available in an SO-8 package. Samples of the L6728 and L6728A are available, with volume production in 4Q 2007. They are supplied in a 3 millimeter x 3 millimeter DFN package.
Source: STMicroelectronics (ST).