FDMF5839: Smart Power Stage (SPS) Module with Integrated Thermal Warning and Thermal Shutdown

The SPS family is Fairchild’s next-generation, fully optimized, ultra-compact, integrated MOSFET plus driver power stage solution for high-current, high-frequency, synchronous buck, DC-DC applications. The FDMF5839 integrates a driver IC with a bootstrap Schottky diode, two power MOSFETs, and a thermal monitor into a thermally enhanced, ultra-compact 5 mm x 5 mm package.

With an integrated approach, the SPS switching power stage is optimized for driver and MOSFET dynamic performance, minimized system inductance, and power MOSFET RDS(ON). The SPS family uses Fairchild's high-performance PowerTrench® MOSFET technology, which reduces switch ringing, eliminating the need for a snubber circuit in most buck converter applications.

A driver IC with reduced dead times and propagation delays further enhances the performance. A thermal warning function warns of a potential over-temperature situation. A thermal shutdown function turns off the driver if an over-temperature condition occurs. The FDMF5839 incorporates an Auto-DCM Mode (ZCD#) for improved light-load efficiency. The FDMF5839 also provides a 3-state 5 V PWM input for compatibility with a wide range of PWM controllers.

Features

• Ultra-Compact 5 mm x 5 mm PQFN Copper-Clip Package with Flip Chip Low-Side MOSFET
• High Current Handling: 35 A
• 3-State 5 V PWM Input Gate Driver
• Dynamic Resistance Mode for Low-Side Drive (LDRV) Slows Low-Side MOSFET during Negative Inductor Current Switching
• Auto DCM (Low-Side Gate Turn Off) Using ZCD# Input
• Thermal Warning (THWN#) to Warn Over-Temperature of Gate Driver IC
• Thermal Shutdown (THDN)
• HS-Short Detect Fault# / Shutdown
• Dual Mode Enable / Fault# Pin
• Internal Pull-Up and Pull-Down for ZCD# and EN Inputs, respectively
• Fairchild PowerTrench® MOSFETs for Clean Voltage Waveforms and Reduced Ringing
• Fairchild SyncFET™ Technology (Integrated Schottky Diode) in Low-Side MOSFET
• Integrated Bootstrap Schottky Diode
• Optimized / Extremely Short Dead-Times
• Under-Voltage Lockout (UVLO) on VCC
• Optimized for Switching Frequencies up to 1.5 MHz
• PWM Minimum Controllable On-Time: 30 ns
• Low Shutdown Current: < 3 µA
• Optimized FET Pair for Highest Efficiency: 10 ~ 15% Duty Cycle
• Operating Ambient Temperature Range: -40°C to +125°C
• Fairchild Green Packaging and RoHS Compliance