MIC22950 10A Integrated Switch Synchronous Buck Regulator with Frequency Programmable to 2MHz General Description Features The Micrel MIC22950 is a high-efficiency 10A integrated 2.6V to 5.5V supply voltage switch, synchronous buck (step-down) regulator. The Fully-integrated MOSFET switches MIC22950 switching frequency is programmable from Adjustable output voltage option down to 0.7V 400kHz to 2MHz, allowing the customer to optimize Output load current up to 10A designing either for efficiency or for the smallest footprint. Full sequencing and tracking capability The MIC22950 achieves over 95% efficiency while still Power-On Reset switching at 2MHz over a broad load range. Efficiency >95% across a broad load range The ultra-high-speed control loop keeps the output voltage Operating frequency programmable: 400kHz to 2MHz within regulation, even under extreme transient load swings commonly found in FPGAs and low voltage ASICs. Ultra-fast transient response 100% maximum duty cycle The output voltage can be adjusted down to 0.7V in order to address all low-voltage power needs. Micropower shutdown Thermal-shutdown and current-limit protection The MIC22950 features a full range of sequencing and tracking options. The EN/DLY and the DELAY pins, Available in a 32-pin 5mm x 5mm MLF package combined with the POR/PG pin, allow multiple outputs to 40C to +125 C junction temperature range be sequenced in several ways during turn-on and turn-off by using EN pin. The RC (Ramp Control) pin allows the Applications device to be connected to any another device in the MIC22x00 family of products, to keep the output voltages High-power density point-of-load conversion within a certain delta V during start-up. Base stations, Servers and Routers The MIC22950 is available in a 32-pin 5mm x 5mm MLF Blu-ray players, DVD Recorders with a junction operating range from 40 C to +125 C. Computer Peripherals Datasheet and supporting documentation can be found on FPGAs, DSP, and low-voltage ASIC power Micrels web site at: www.micrel.com. Typical Application Efficiency vs. Load Current 100 95 90 85 80 75 70 VIN = 5V 65 VOUT = 3.3V TA = 25C 60 02 46 8 10 LOAD CURRENT (A) MIC22950 10A Synchronous DC-DC Converter Sequencing and Tracking Ramp Control is a trademark of Micrel, Inc 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. MIC22950 Ordering Information Part Number Nominal Output Voltage Temperature Range Package Lead Finish MIC22950YML Adjustable 40 to +125C 32-Pin 5mm x 5mm MLF Lead Free Note: MLF is a GREEN RoHS-compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free. Pin Configuration 32-Pin 5mm x 5mm MLF (ML) Pin Description Pin Number Pin Name Pin Function 1,2,7,8,17,23,24 PVIN Power Supply Voltage (Input): Requires bypass capacitor to PGND. Enable/ delay (Input): This pin has a 1.24V band gap reference. When the pin is pulled higher that this the part will start up. Below this voltage the device is in its low quiescent current mode. 3 EN/DLY The pin has a 1A current source pull-up to VIN. By adding a capacitor to this pin, a delay may be generated. The enable function will not operate with an input voltage lower than UVLO. Delay (Input): A capacitor sets the internal delay timer. Timer delays power-on reset (POR) at 4 DELAY power-up and power-down. Ramp Control (Input): Capacitor-to-ground from this pin determines slew rate of output voltage 5 RC during start-up. This can be used for tracking capability as well as soft start. RC pin cannot be left floating. Use a minimum capacitor value of 120pF or larger. Power-On-Reset (Output): Open-drain output device indicates when the output is out of 6 POR/PG regulation and is active after the delay set by the DELAY pin. 9,10,15,16,25,26, PGND Power Ground (Power): Power Ground. 31,32 11,12,13,14,27, SW Switch (Output): Internal power MOSFET output switches. 28,29,30 18 SGND Signal Ground (Signal): Signal Ground. 19 CF Frequency Set (Input): Adjustable Frequency with external capacitor. Feedback (Input): Input to the error amplifier, connect to the external resistor divider network to 20 FB set the output voltage. Compensation pin (Input): Place a RC-to-SGND to compensate the device, see applications 21 COMP section. 22 SVIN Signal Power Supply Voltage (Input): Requires bypass capacitor-to-SGND. Center Tab (Power): Must make a full connection to a GND plane for full output power to be EP GND realized. M9999-021910-B February 2010 2