LTC3309B Datasheet

• Pin Compatible with LTC3307(3A) and LTC3308(4A)
• High Efficiency: 8mΩ NMOS, 31mΩ PMOS
• Programmable Frequency 3MHz-10MHz
  • Tiny Inductor and Capacitors
• Peak Current Mode Control
  • 22ns Minimum On-Time
  • Wide Bandwidth, Fast Transient Response
• Silent Switcher^™ Architecture
  • Ultralow EMI Emissions
• Low Ripple Burst Mode^® Operation with IQ of 40μA
• Safely Tolerates Inductor Saturation in Overload
• V_IN Range: 2.25V to 5.5V
• V_OUT Range: 0.5V to V_IN
• V_OUT Accuracy: ±1% Over Temperature Range
• Precision 400mV Enable Threshold, 1μA in Shutdown
• Power Good, Internal Compensation and Soft Start
• Thermally Enhanced 2mm × 2mm LQFN Package
• AEC-Q100 Qualified for Automotive Applications

• Optical Networking, Servers, Telecom
• Automotive, Industrial, Communications
• Distributed DC Power Systems (POL)
• FPGA, ASIC, µP Core Supplies

The LTC3309B is a very small, high efficiency, low noise, monolithic synchronous 6A step-down DC/DC converter operating from a 2.25V to 5.5V input supply. Using constant frequency, peak current mode control at switching frequencies 3MHz-10MHz and minimum on-time as low as 22ns, this regulator achieves fast transient response with small external components. Silent Switcher architecture minimizes EMI emissions.

The LTC3309B operates in forced continuous or pulse skip mode for low noise, or the low-ripple Burst Mode operation for high efficiency at light loads, ideal for battery-powered systems. The IC regulates output voltages as low as 500mV. Other features include output over-voltage protection, short-circuit protection, thermal shut-down, clock synchronization, and up to 100% duty cycle operation for low dropout. The device is available in a low profile 12-lead 2mm × 2mm × 0.74mm LQFN package with exposed pad for low thermal resistance.