TPS65251-3 Datasheet | Texas Instruments

Features - 1 Wide Input Supply Voltage Range (4.5 to 18 V) - Output Range 0.8 V to VIN - 1 V - Continuous Loading: 3 A (Buck 1), 2 A (Buck 2 and 3) - Maximum Current: 3.5 A (Buck 1), 2.5 A (Buck 2 and 3) - Adjustable Switching Frequency 300 k Hz to 2.2 MHz Set by External Resistor - Dedicated Enable for Each Buck - External Synchronization Pin for Oscillator - Adjustable Current Limit Set by External Resistor - Soft-Start Pins - Current-Mode Control With Simple pensation Circuit - Power Good - Automatic PFM/PWM Operation - VQFN Package, 40-Pin 6-mm × 6-mm RHA 2 Applications - Set Top Boxes - Blu-ray™ DVD - DVR - DTV - Car Audio/Video - Security Camera 3 Description The TPS65251-x features three synchronous wideinput range, high-efficiency buck converters. The converters are designed to simplify its application while giving the designer the option to optimize their usage according to the target application. The converters can operate in 5-, 9-, 12- or 15-V systems and have integrated power transistors. The output voltage can be set externally using a resistor divider to any value between 0.8 V and close to the input supply. Each converter features an enable pin that allows a delayed start-up for sequencing purposes, soft-start pin that allows adjustable softstart time by choosing the soft-start capacitor, and a current limit (RLIMx) pin that enables the designer to adjust current limit by selecting an external resistor and optimize the choice of inductor. The current mode control allows a simple RC pensation. The switching frequency of the converters can either be set with an external resistor connected to ROSC pin or can be synchronized to an external clock connected to the SYNC pin if needed. The switching regulators are designed to operate from 300 k Hz to 2.2 MHz. 180° out-of-phase operation between Buck 1 and Buck 2, 3 (Buck 2 and 3 run in phase) minimizes the input filter requirements. TPS65251-x features a supervisor circuit that monitors each converter output....