Silego intros GreenFET N-channel MOSFET drivers for ultra-low cost power supply sequencing

SANTA CLARA, USA: Silego Technology Inc. announced a family of GreenFET N-Channel MOSFET drivers. N-Channel MOSFETs are difficult to use, but are more efficient for an equivalent cost as compared to P-Channel MOSFETs.

GreenFET drivers allow the easy use of N-Channel MOSFETs instead of P-Channel MOSFETs in load switch applications saving money and reducing power consumption by up to 2 W.

The GreenFET drivers are targeted at sequencing multiple power rails in computer servers, Communication equipment, Industrial equipment and anywhere high current, low Rds(on) P-Channel MOSFETs are used to switch loads.

GreenFETs drivers, when used in combination for all system power rails result in the lowest cost, robust, high efficiency power supply sequencing system. Most GreenFET drivers come with a power good (PG) signal that indicates when the power rail is within specification. Complicated power supply sequencing systems may be easily designed by utilizing the PG feature and selectable delay and ramp rates.

Further, less costly and fewer components are required because no charge pumps, no discrete RC delays, and no associated signal transistors are needed, less power rail routing is required, and no expensive power controlling CPLDs, FPGAs, and power sequencing ASICs.

“Silego’s GreenFET drivers enable the greater efficiency of N-Channel MOSFETs to be enjoyed without the associated technical difficulty and cost,” said John McDonald, vice president of marketing and sales at Silego. “The success of the GreenFET family builds on Silego’s corporate goal of providing ICs that reduce component count, simplify design, while saving power and board space.”

GreenFET drivers consume <1 µA when not actively switching. Most N-channel MOSFET discrete load switching circuits leak current when OFF and do not pump the gate voltage high enough to achieve the best efficiency.

GreenFET drivers solve both issues by limiting current leakage while driving main power FET with a higher Vgs(ON) for lower Rds(ON). These energy saving features allow Energy Star requirements to be more easily met. GreenFET drivers are not used for driving DC/DC converter FETs.

All GreenFET drivers turn on N-Channel MOSFETs in a nearly perfect linear ramp after a user defined delay period. All GreenFET drivers have a supply discharge feature to ensure that the power rail turns off as nicely as it was turned on. N-Channel MOSFETs controlled by GreenFET drivers have little turn-on and turn-off variation as a function of temperature or voltage ensuring higher production yields and less concern with testing power sequencing corner conditions.