ACT  -  Series DataSheet
ACT4082A  -  16V, 1.2A, 1.4MHz Step-Down DC/DC Converter in SOT23-6  -  Active Semi  -  DC-DC

FEATURES
• Wide 4.5V to 16V Input Voltage Range
• 1.2A Output Current (12VIN to 5VOUT)
• Output Adjustable Down to 0.81V
• 0.3Ω Internal Power MOSFET
• Up to 92% Efficiency
• Stable with Low ESR Ceramic Output Capacitors
• Fixed 1.4MHz Operating Frequency
• Internal Soft-Start Function
• Over Current Protection with Hiccup-Mode
• Thermal Shutdown
• Available in a SOT23-6 Package
APPLICATIONS
• TFT LCD Monitors
• Portable DVDs, Headphones, MP3 Players, etc.
• Car-Powered or Battery-Powered Equipment
• Set-Top Boxes
• Telecom Power Supplies
• DSL and Cable Modems and Routers
GENERAL DESCRIPTION
The ACT4082A is a current-mode step-down DC/DC converter that supplies up to 1.2A into 5V from a 12V input. 1.4MHz switching frequency allows the use of tiny external components, and internal loop compensation provides simple, stable power supplies with a minimum of external components.
Optimized for use with ceramic input and output capacitors, the ACT4082A provides a very compact 1.2A power supply for space constrained mobile and consumer applications.
The ACT4082A operates over a wide input voltage range and utilizes current-mode operation to provide excellent line and load transient response while requiring no external compensation components.
Fault protection includes cycle-by-cycle current limiting, frequency fold-back, hiccup mode, and thermal shutdown. Internal soft-start provides a controlled startup with no overshoot, even at light loads.
The ACT4082A is available in a tiny SOT23-6 package and requires very few external components.