MIC4722 3mm x 3mm 2.7MHz 3A PWM Buck Regulator General Description Features The Micrel MIC4722 is a high efficiency PWM buck (step- 2.7 to 5.5V supply voltage down) regulator that provides up to 3A of output current. 2.7MHz PWM mode The MIC4722 operates at 2.7MHz that makes it suitable Output current to 3A for next generation XDSL modems requiring operating >92% efficiency frequencies in excess of 2.4MHz and has proprietary internal compensation that allows a closed loop bandwidth 100% maximum duty cycle of over 200KHz. Adjustable output voltage option down to 1V The low on-resistance internal p-channel MOSFET of the Ultra-fast transient response MIC4722 allows efficiencies over 92%, reduces external Ultra-small external components components count and eliminates the need for an Stable with a 0.47H inductor and a 4.7F output expensive current sense resistor. capacitor The MIC4722 operates from 2.7V to 5.5V input and the Fully integrated 3A MOSFET switch output can be adjusted down to 1V. The devices can Micropower shutdown operate with a maximum duty cycle of 100% for use in low- Thermal shutdown and current limit protection dropout conditions. Pb-free 12-pin 3mm x 3mm MLF package The MIC4722 is available in the exposed pad 12-pin 3mm x 3mm MLF package with a junction operating 40 C to +125 C junction temperature range range from 40C to +125C. Applications 5V or 3.3V Point of Load Conversion Telecom/Networking Equipment Set Top Boxes Storage Equipment Video Cards Typical Application MIC4722 3A 2.7MHz Buck Regulator MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC4722 Ordering Information Part Number Voltage Junction Temp. Range Package Lead Finish MIC4722YML Adj. 40 to +125C 12-Pin 3x3 MLF Pb-Free Note: MLF is a GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free. Pin Configuration SW 1 12 SW VIN 2 11 VIN PGND 3 10 PGND SGND 4 9 PGOOD BIAS 5 8 EN FB67EP NC 12-Pin 3mm x 3mm MLF (ML) Pin Description Pin Number Pin Name Pin Function 1,12 SW Switch (Output): Internal power P-Channel MOSFET output switch 2,11 VIN Supply Voltage (Input): Supply voltage for the source of the internal P-channel MOSFET and driver. Requires bypass capacitor to GND. 3,10 PGND Power Ground. Provides the ground return path for the high-side drive current. 4 SGND Signal (Analog) Ground. Provides return path for control circuitry and internal reference. 5 BIAS Internal circuit bias supply. Must be bypassed with a 0.1F ceramic capacitor to SGND. 6 FB Feedback. Input to the error amplifier, connect to the external resistor divider network to set the output voltage. 7 NC No Connect. Not internally connected to die. This pin can be tied to any other pin if desired. 8 EN Enable (Input). Logic level low, will shutdown the device, reducing the current draw to less than 5A. 9 PGOOD Power Good. Open drain output that is pulled to ground when the output voltage is within +/- 7.5% of the set regulation voltage EP GND Connect to ground. M9999-051410-C May 2010 2