1FEATURES
• Fully Integrated Power Switches With Drivers
for Single and Multiphase Synchronous Buck
Converters
• Full Compatibility With TI Fusion Digital Power
Supply Controllers, (UCD91xx and UCD92xx
Families)
• Compatible With Analog Domain Controllers
• Wide Input Voltage Range: low–
4.5 V to 18 V
– Operational Down to 2.2-V Input With an
External Bias Supply
• Up to 6-A Output Current
• Operational to 2-MHz Switching Frequency
• Current Limit With Current Limit Flag
• Onboard Regulated 6-V Driver Supply From
VIN
• Thermal Protection and Monitoring

lowAPPLICATIONS
• Digitally-Controlled Synchronous-Buck Power
Stage for Single and Multi-Phase Applications
• High Efficiency Small Size Regulators for
Desktop, Server, Telecom and Notebook
Applications
• Synchronous-Buck Power Stages

DESCRIPTION
The UCD74106 is a complete power system ready to
drive a buck power supply (Figure 1). High-side
MOSFETs, low-side MOSFETs, drivers, current
sensing circuitry and necessary protection functions
are all integrated into one monolithic solution to
facilitate minimum size and maximum efficiency.
Driver circuits provide high charge and discharge
current for the high-side NMOS switch and the low–
side NMOS synchronous rectifier in a synchronous
buck circuit. The MOSFET gates are driven to 6.25 V
by an internally regulated VGG supply. The internal
VGG regulator can be disabled to permit the user to
supply an independent gate drive voltage. This
flexibility allows a wide power conversion input
voltage range of 2.2 V to 18 V. Internal Under
Voltage Lockout (UVLO) logic insures VGG is good
before allowing chip operation.
A drive logic block allows operation in one of two
modes. In synchronous mode, the logic block uses
the PWM signal to control both the high-side and lowAPPLICATIONS
side gate drive signals. Dead time is optimized to
prevent cross conduction. The synchronous rectifier enable (SRE) pin controls whether or not the low-side
FET is turned on when the PWM signal is low.