AOZ1284 EZBuck 4A Simple Buck Regulator General Description Features The AOZ1284 is a high voltage, high efficiency, 3.0V to 36V operating input voltage range simple to use, 4A buck regulator optimized for a 50m internal NMOS variety of applications. The AOZ1284 works from a Efficiency up to 95% 3.0V to 36V input voltage range, and provides up to Adjustable soft-start 4A of continuous output current. The output voltage is adjustable from 30V down to 0.8V. Output voltage adjustable from 0.8V to 30V 4A continuous output current Adjustable switching frequency from 200kHz to The AOZ1284 integrates an N-channel high-side 2MHz power MOSFET. The switching frequency can set Cycle-by-cycle current limit from 200kHz to 2MHz with an external resistor. The Short-circuit protection soft-start time can be set with an external capacitor. Over-voltage protection Over-temperature protection EPAD SO-8 package Applications Point of load DC/DC conversion Set top boxes and cable modems Automotive applications DVD drives and HDDs LCD Monitors & TVs Telecom/Networking/Datacom equipment Typical Application Figure 1. 36V/4A Buck Regulator Rev. 0.5 March 2012 www.aosmd.com Page 1 of 14 AOZ1284 Ordering Information Part Number Temperature Range Package Environmental AOZ1284PI -40C to +85C EPAD SO-8 Green Product AOZ1284PI-1 AOS Green Products use reduced levels of Halogens, and are also RoHS compliant. Please visit www.aosmd.com/media/AOSGreenPolicy.pdf for additional information. Pin Configuration 1 8 LX EN 2 7 BST SS Exposed PAD 3 6 GND FB VIN 4 5 FSW COMP EPAD SO-8 (Top View) Pin Description Part Number Pin Name Pin Function 1 LX PWM Output Pin. Connect to inductor. 2 BST Bootstrap Voltage Pin. Driver supply for High Side NMOS. Connected to 100nF capacitor between BST and LX. 3 GND Ground Pin. 4 FSW Frequency Bias Pin. Connect to resistor to determine switching frequency. 5 COMP Compensation Pin. Connect to Resistor and Capacitor for system stability. 6 FB Feedback Pin. 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 Ground. 7 SS Soft Start Pin. 8 EN Enable Pin. Exposed PAD VIN Supply Voltage Pin. www.aosmd.com Page 2 of 14 Rev. 0.5 March 2012