AOZ1051PI EZBuck 3 A Synchronous Buck Regulator General Description Features The AOZ1051PI is a high efficiency, easy to use, 3 A z 4.5 V to 18 V operating input voltage range synchronous buck regulator. The AOZ1051PI works from z Synchronous Buck: 70 m internal high-side switch 4.5 V to 18 V input voltage range, and provides up to 3 A and 40 m internal low-side switch (at 12 V) of continuous output current with an output voltage z Up to 95 % efficiency adjustable down to 0.8 V. z External soft start The AOZ1051PI comes in an exposed pad SO-8 z Output voltage adjustable to 0.8 V package and is rated over a -40 C to +85 C operating z 3 A continuous output current ambient temperature range. z 500 kHz PWM operation z Cycle-by-cycle current limit z Pre-bias start-up z Short-circuit protection z Thermal shutdown z Exposed pad SO-8 package Applications z Point of load DC/DC converters z LCD TV z Set top boxes z DVD and Blu-ray players/recorders z Cable modems Typical Application VIN C1 C SS 10F VIN SS L1 4.7H EN VOUT LX AOZ1051PI R1 COMP C2, C3 R C FB 22F AGND PGND R2 C C Figure 1. 3.3 V 3 A Synchronous Buck Regulator, Fs = 500 kHz Rev. 1.0 June 2011 www.aosmd.com Page 1 of 14 Not Recommended For New DesignsAOZ1051PI Ordering Information Part Number Ambient Temperature Range Package Environmental AOZ1051PI -40 C to +85 C EPAD SO-8 Green Product AOS Green Products use reduced levels of Halogens, and are also RoHS compliant. Please visit www.aosmd.com/web/quality/rohs compliant.jsp for additional information. Pin Configuration 1 8 PGND NC 2 7 VIN SS PAD (LX) 3 6 AGND EN 4 5 FB COMP Exposed Pad SO-8 (Top View) Pin Description Pin Number Pin Name Pin Function 1 PGND Power ground. PGND needs to be electrically connected to AGND. 2 VIN Supply voltage input. When VIN rises above the UVLO threshold and EN is logic high, the device starts up. 3 AGND Analog ground. AGND is the reference point for controller section. AGND needs to be electrically connected to PGND. 4 FB Feedback input. The FB pin is used to set the output voltage via a resistive voltage divider between the output and AGND. 5 COMP External loop compensation pin. Connect a RC network between COMP and AGND to compensate the control loop. 6 EN Enable pin. Pull EN to logic high to enable the device. Pull EN to logic low to disable the device. If on/off control in not needed, connect EN to VIN and do not leave it open. 7 SS Soft-start pin. 5 A current charging current. 8 NC No Connect Pin. Pin 8 is not internally connected. Connect this pin externally to LX and use it for better thermal performance. Exposed pad LX Switching node. LX is the drain of the internal PFET. LX is used as the thermal pad of the power stage. Rev. 1.0 June 2011 www.aosmd.com Page 2 of 14 Not Recommended For New Designs