Analog Devices LTC3634

Description

The LTC®3634 is a high efficiency, dual-channel monolithic synchronous step-down regulator which provides power supply and bus termination rails for DDR1, DDR2, and DDR3 SDRAM controllers. The operating input voltagerange is 3.6V to 15V, making it suitable for point-of-load power supply applications from a 5V or 12V input, as well as various battery powered systems.The VTT regulated output voltage is equal to VDDQIN•0.5. An on-chip buffer capable of driving a 10mA load pro- vides a low noise reference output (VTTR) also equal to VDDQIN •0.5.The operating frequency is programmable and synchronizable from 500kHz to 4MHz with an external resistor. The two channels can operate 180° out-of-phase, which relaxes the requirements for input and output capacitance.The unique controlled on-time architecture is ideal for powering DDR applications from a 12V supply at high switching frequencies, allowing the use of smaller external components.The LTC3634 is offered in both 28-pin 4mm × 5mm QFN and 28-pin exposed pad TSSOP packages.

Features

• 3.6V to 15V Input Voltage Range
• ±3A Output Current per Channel
• Up to 95% Efficiency
• Selectable 90°/180° Phase Shift Between Channels
• Adjustable Switching Frequency: 500kHz to 4MHz
• VTTR = VDDQ/2 = VTT Reference
• ±1.6% Accurate VTTR at 0.75V
• Optimal VOUT Range: 0.6V to 3V
• ±10mA Buffered Output Supplies VREF Reference Voltage
• Current Mode Operation for Excellent Line and Load Transient Response
• External Clock Synchronization
• Short-Circuit Protected
• Input Overvoltage and Overtemperature Protection
• Power Good Status Outputs
• Available in (4mm × 5mm) QFN-28 and Thermally Enhanced 28-Lead TSSOP Packages

Note: Inductor Selection Table is mentioned in page 14

Typical applications

• DDR Memory Power Supplies

More information

• Datasheet
• IC product information