LT3501EFE#TRPBF Power Path Management IC Dual Tracking 3A Step-Down Switching Regulator

FeaTures

n Wide Input Range: 3.1V to 25V
n Two Switching Regulators with 3A Output Capability n Independent Supply to Each Regulator
n Adjustable/Synchronizable Fixed Frequency Operation from 250kHz to 1.5MHz
n Antiphase Switching
n Outputs Can be Paralleled
n Independent, Sequential, Ratiometric or Absolute Tracking Between Outputs
n Independent Soft-Start and Power Good Pins
n Enhanced Short-Circuit Protection
n Low Dropout: 95% Maximum Duty Cycle
n Low Shutdown Current: <10μA
n 20-Lead TSSOP Package with Exposed Leadframe

ApplicaTions

n DSP Power Supplies
n Disc Drives
n DSL/Cable Modems
n Wall Transformer Regulation n Distributed Power Regulation

L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.

DescripTion

The LT®3501 is a dual-current mode PWM step-down DC/DC converter with two internal 3.5A switches. Inde- pendent input voltage, feedback, soft-start and power good pins for each channel simplify complex power supply tracking/sequencing requirements.

Both converters are synchronized to either a common external clock input or a resistor programmable xed 250kHz to 1.5MHz internal oscillator. At all frequencies, a 180° phase relationship between channels is maintained, reducing voltage ripple and component size. Programmable frequency allows for optimization between ef ciency and external component size.

Minimum input-to-output voltage ratios are improved by allowing the switch to stay on through multiple clock cycles, only switching off when the boost capacitor needs recharging, resulting in ~95% maximum duty cycle.

Each output can be independently disabled using its own soft-start pin, or by using the SHDN pin the entire part can be placed in a low quiescent current shutdown mode.

The LT3501 is available in a 20-lead TSSOP package with exposed leadframe for low thermal resistance.