MIC4723 3A 2MHz Integrated Switch Buck Regulator General Description Features The Micrel MIC4723 is a high efficiency PWM buck (step- 2.7/3.0V to 5.5V supply voltage down) regulator that provides up to 3A of output current. 2.0MHz PWM mode The MIC4723 operates at 2.0MHz and has proprietary Output current to 3A internal compensation that allows a closed loop bandwidth Up to 94% efficiency of over 200KHz. 100% maximum duty cycle The low on-resistance internal p-channel MOSFET of the Adjustable output voltage option down to 1V MIC4723 allows efficiencies over 92%, reduces external Ultra-fast transient response components count and eliminates the need for an Ultra-small external components expensive current sense resistor. Stable with a 1H inductor and a 4.7F output The MIC4723 operates from 2.7V to 5.5V input and the capacitor output can be adjusted down to 1V. The devices can Fully integrated 3A MOSFET switch operate with a maximum duty cycle of 100% for use in low- Micropower shutdown dropout conditions. Thermal shutdown and current limit protection The MIC4723 is available in the exposed pad 12-pin Pb-free 12-pin 3mm x 3mm MLF package 3mm x 3mm MLF and 10-pin ePAD MSOP packages with Pb-free 10-pin ePAD MSOP package a junction operating range from 40C to +125C. 40 C to +125 C junction temperature range Data sheets and support documentation can be found on Micrels web site at: www.micrel.com. Applications FPGA/DSP/ASIC applications General point of load Broadband communications DVD/TV recorders Point of sale Printers/Scanners Set top boxes Computing peripherals Video cards Typical Application MIC4723 3.3V Efficiency OUT 96 4.5V IN 94 5V IN 92 90 5.5V IN 88 86 84 82 80 78 3A 2MHz Buck Regulator 76 0 0.5 1 1.5 2 2.5 3 OUTPUT CURRENT (A) 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. MIC4723 Ordering Information Part Number Voltage Temperature Range Package Lead Finish MIC4723YML Adj. 40 to +125C 12-Pin 3x3 MLF Pb-Free MIC4723YMME Adj. 40 to +125C 10-Pin ePAD MSOP 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 SW 1 10 SW VIN 2 11 VIN VIN 2 9 VIN PGND 3 10 NC SGND 3 8 PGND SGND 4 9 PGOOD BIAS 4 7 PGOOD EP BIAS 5 8 EN FB 5 6 EN FB67EP NC 12-Pin 3mm x 3mm MLF (ML) 10-Pin ePAD MSOP (MME) Pin Description Pin Number Pin Number Pin Name Pin Function MLF-12 MSOP-10 1, 12 1, 10 SW Switch (Output): Internal power P-Channel MOSFET output switch. 2, 11 2, 9 VIN Supply Voltage (Input): Supply voltage for the source of the internal P-channel MOSFET and driver. Requires bypass capacitor to GND. 3 8 PGND Power Ground. Provides the ground return path for the high-side drive current. 4 3 SGND Signal (Analog) Ground. Provides return path for control circuitry and internal reference. 5 4 BIAS Internal circuit bias supply. Must be bypassed with a 0.1F ceramic capacitor to SGND. 6 5 FB Feedback. Input to the error amplifier, connect to the external resistor divider network to set the output voltage. 7, 10 NC No Connect. Not internally connected to die. This pin can be tied to any other pin if desired. 8 6 EN Enable (Input). Logic level low, will shutdown the device, reducing the current draw to less than 5A. 9 7 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 EP GND Connect to ground. M9999-060308-E June 2008 2