ISL6208

The ISL6208 and ISL6208B are high frequency, dual MOSFET drivers, optimized to drive two N-Channel power MOSFETs in a synchronous-rectified buck converter topology. They are especially suited for mobile computing applications that require high efficiency and excellent thermal performance. These drivers, combined with an Intersil multiphase Buck PWM controller, form a complete single-stage core-voltage regulator solution for advanced mobile microprocessors. ISL6208 and ISL6208B have the same function but different packages. The descriptions in this datasheet are based on ISL6208 and also apply to ISL6208B. The ISL6208 features 4A typical sinking current for the lower gate driver. This current is capable of holding the lower MOSFET gate off during the rising edge of the Phase node. This prevents shoot-through power loss caused by the high dv/dt of phase voltages. The operating voltage matches the 30V breakdown voltage of the MOSFETs commonly used in mobile computer power supplies. The ISL6208 also features a three-state PWM input that, working together with Intersil’s multiphase PWM controllers, will prevent negative voltage output during CPU shutdown. This feature eliminates a protective Schottky diode usually seen in a microprocessor power systems. MOSFET gates can be efficiently switched up to 2MHz using the ISL6208. Each driver is capable of driving a 3000pF load with propagation delays of 8ns and transition times under 10ns. Bootstrapping is implemented with an internal Schottky diode. This reduces system cost and complexity, while allowing the use of higher performance MOSFETs. Adaptive shoot-through protection is integrated to prevent both MOSFETs from conducting simultaneously. A diode emulation feature is integrated in the ISL6208 to enhance converter efficiency at light load conditions. This feature also allows for monotonic start-up into pre-biased outputs. When diode emulation is enabled, the driver will allow discontinuous conduction mode by detecting when the inductor current reaches zero and subsequently turning off the low side MOSFET gate.