ISL6208A

Features:

• Dual MOSFET Drives for Synchronous Rectified Bridge
• Adaptive Shoot-Through Protection
- Active Gate Threshold Monitoring
- Programmable Dead-Time
• 0.5 On-Resistance and 4A Sink Current Capability
• Supports High Switching Frequency up to 2MHz
- Fast Output Rise and Fall Time
- Low Propagation Delay
• Three-State PWM Input for Power Stage Shutdown
• Internal Bootstrap Schottky Diode
• Low Bias Supply Current (5V, 100A)
• Diode Emulation for Efficiency and Pre-Biased Startup
• VCC POR (Power-On-Reset) Feature Integrated
• Pin-to-pin Compatible with ISL6207, ISL6208, ISL6209
• QFN Package:
- Compliant to JEDEC PUB95 MO-220 QFN - Quad Flat No Leads - Package Outline
- Near Chip Scale Package footprint, which improves PCB efficiency and has a thinner profile
• Pb-Free Plus Anneal Available (RoHS Compliant)




Application

• Supplies for Intel^® and AMD^® Mobile Microprocessors
• High Frequency, Low Profile DC/DC Converters
• High Current Low Output Voltage DC/DC Converters
• High Input Voltage DC/DC Converters




Pinout






Specifications

Supply Voltage (VCC) . . . . . . . . . . . . .. . . . . . . . . . . -0.3V to 7V
Input Voltage (V_FCCM, V_PWM). . . . . . . ...... . . . . . -0.3V to VCC + 0.3V
BOOT Voltage (V_BOOT-GND). . . . . . . . . . . . . . . . . . . . -0.3V to 33V
BOOT To PHASE Voltage (V_BOOT-PHASE) ..... . . . . . -0.3V to 7V (DC) -0.3V to 9V (<10ns)
PHASE Voltage (Note 1) . . . . . . . . . .... . . . . . . . . .GND - 0.3V to 30V GND -8V (<20ns Pulse Width, 10J)
UGATE Voltage . . . . . . . . . . . . . . .............. . V_PHASE - 0.3V (DC) to VBOOT V_PHASE - 5V (<20ns Pulse Width, 10J) to VBOOT
LGATE Voltage . . . . . . . . . . . . ............... . . GND - 0.3V (DC) to VCC + 0.3V GND - 2.5V (<20ns Pulse Width, 5J) to VCC + 0.3V
Ambient Temperature Range. . . . . . . . . . . . . . . . . . .-40°C to 125°C




Description

The ISL6208A is a high frequency, dual MOSFET driver, optimized to drive two N-Channel power MOSFETs in a synchronous-rectified buck converter topology. It is especially suited for mobile computing applications that require high efficiency and excellent thermal performance. This driver, combined with an Intersil multiphase Buck PWM controller, forms a complete single-stage core-voltage regulator solution for advanced mobile microprocessors.

The ISL6208A 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 ISL6208A 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 ISL6208A. Each driver is capable of driving a 3000pF load with propagation delays of 15ns and transition times under 10ns. Bootstrapping is implemented with an interna 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 ISL6208A 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. Programmable dead-time control with gate threshold monitoring is also integrated to prevent both MOSFETs from conducting simultaneously.