New Control MOSFET with 40% reduced Qg and Synchronous MOSFET with 25% improved RDS(on) Boost Battery Life in Portable Electronics Applications
International Rectifier introduces the IRF7821 and IRF7832 synchronous buck converter chip set designed to increase battery life in notebook computers. Other applications for the new HEXFET® MOSFETs include buck converters for computer server power systems and graphics cards, as well as point-of-load converters in telecom and datacom systems.
For maximum MOSFET efficiency, the goal is to reduce device on-resistance, or RDson, to minimize conduction loss, and to reduce gate charge (Qg) and gate-to-drain charge (Qgd) to minimize switching loss. IR's stripe trench HEXFET® MOSFET technology enables devices characterized with dramatically reduced RDS(on), Qg and Qgd, resulting in more than 1% increased system efficiency compared to systems using similar competing devices. In addition, reverse recovery charge, Qrr, has been reduced to minimize reverse recovery loss.
The IRF7821 has 10nC Qg and 2.5nC Qgd, making it well suited as a control MOSFET, and features a 40% reduction in gate charge compared to similar competing devices.
The IRF7832 has 4.0mOhm max. RDS(on) at 10VGS, making it ideal for the synchronous MOSFET application, and delivers a 25% improvement in device on-resistance compared to similar competing devices. The IRF7832 can also be used for secondary-side synchronous rectification in isolated converters.
Ralph Monteiro, Product Marketing Engineer for Computing Products at International Rectifier said, "The IRF7821 and IRF7832 chip set features improved efficiency over the entire load range. The low gate charge results in higher efficiency at light loads, which is important for longer battery life in portable applications. The higher efficiency also enables improved thermal characteristics and reduces part count. This makes the IRF7821 and IRF7832 the ideal MOSFET chip set for Vcore power in the new Intel® CentrinoTM processor."
| Part Number | Package | BVDSS Max.(V) | RDS(on) @10V Max.(mW) | RDS(on) @4.5V Max. (mW) | VGS Max. (V) | QG Typ. (nC) | QGD Typ. (nC) | Function |
| IRF7821 | SO-8 | 30 | 9.1 | 12.5 | 20 | 10.0 | 2.5 | Control FET |
| IRF7832 | SO-8 | 30 | 4.0 | 4.8 | 20 | 34.0 | 14.0 | Synch FET |
Pricing and Availability
The new IRF7821 and IRF7832 synchronous buck chip set is available now. Pricing is US $0.42 each for the IRF7821 and US $0.70 each for the IRF7832 in 10,000-unit quantities.
