AOZ1242AI Alpha & Omega

AOZ1242 EZBuck 3A Simple Buck Regulator General Description Features The AOZ1242 is a high efficiency, simple to use, 3A buck 4.5V to 32V operating input voltage range regulator flexible enough to be optimized for a variety of 70m internal NFET, efficiency: up to 95% applications. The AOZ1242 works from a 4.5V to 32V Internal soft start input voltage range, and provides up to 3A of continuous Output voltage adjustable down to 0.8V output current on each buck regulator output. The output voltage is adjustable down to 0.8V. 3A continuous output current Fixed 370kHz PWM operation The AOZ1242 comes in an SO-8 or DFN-8 package and Cycle-by-cycle current limit is rated over a -40C to +85C ambient temperature range Short-circuit protection Thermal shutdown Small size, SO-8 or DFN-8 package Applications Point of load DC/DC conversion Set top boxes DVD drives and HDD LCD monitors & TVs Cable modems Telecom/networking/datacom equipment Typical Application C7 VIN C1 22F VIN BS L1 6.8H VOUT EN LX AOZ1242 R1 C2, C3 VBIAS FB 22F x 2 R2 C4 GND COMP R C C C Figure 1. 3.3V/3A Buck Regulator Rev. 1.4 November 2010 www.aosmd.com Page 1 of 18AOZ1242 Ordering Information Part Number Ambient Temperature Range Package Environmental AOZ1242AI -40C to +85C SO-8 Green Product AOZ1242DI -40C to +85C DFN-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 LX VBIAS 1 8 LX VBIAS VIN 2 7 BST VIN 2 7 BST VIN 3 6 3 6 GND EN GND EN GND 4 5 FB COMP 4 5 FB COMP SO-8 DFN-8 (Top View) (Top Thru View) Pin Description Pin Number Pin Name Pin Function 1 LX PWM output connection to inductor. LX pin needs to be connected externally. Thermal connection for output stage. 2 BST Bootstrap voltage input. High side driver supply. Connected to 0.1F capacitor between BST and LX. 3 GND Ground. 4 FB Feedback input. It is regulated to 0.8V. The FB pin is used to determine the PWM output voltage via a resistor divider between the output and GND. 5 COMP External loop compensation. Output of internal error amplifier. Connect a series RC network to GND for control loop compensation. 6 EN Enable pin. The enable pin is active HIGH. Connect EN pin to V if not used. Do not leave the EN IN pin floating. 7V Supply voltage input. Range from 4.5V to 32V. When V rises above the UVLO threshold the IN IN device starts up. All V pins need to be connected externally. IN 8 VBIAS Compensation pin of internal linear regulator. Place a 1F capacitor between this pin and ground. Rev. 1.4 November 2010 www.aosmd.com Page 2 of 18