MIC2204 Micrel, Inc. MIC2204 High-Efficiency 2MHz Synchronous Buck Converter General Description Features The Micrel MIC2204 is a high-efficiency, 2MHz PWM syn- Input voltage range: 2.3V to 5.5V chronous buck switching regulator. Power conversion effi- Output down to 1V/ 600mA ciency of above 95% is easily obtainable over a wide range 2MHz PWM operation of applications. A proprietary internal compensation tech- Ultra-fast transient response (typical 200kHz GBW) nique ensures stability with the smallest possible inductor Internal compensation and ceramic output capacitor. All ceramic capacitors >95% efficiency The MIC2204 operates from 2.3V to 5.5V input and features Fully integrated MOSFET switches internal power MOSFETs that can supply over 600mA of Easily synchronized to external clock output current with output voltages down to 1V. The MIC2204 SYNCLOCK feature to daisy-chain multiple 2204s implements a constant 2MHz pulse-width-modulation (PWM) <340A quiescent current control scheme which reduces spurious noise in sensitive RF Logic controlled micropower shutdown and communication applications. Additionally, the MIC2204 Thermal shutdown and current limit protection can be synchronized to an external clock, or multiple MIC2204s 10-pin MSOP and 3mm3mm MLF-10L can easily be daisy-chained with the SYNCLOCK feature. 40C to +125C junction temperature range The MIC2204 has a high bandwidth loop (typ. 200kHz) which allows ultra-fast transient response times. This is very useful Applications when powering applications that require fast dynamic re- sponses, such as the CPU cores and RF circuitry in high- High-efficiency portable power performance cellular phones and PDAs. Cellular phones The MIC2204 is available in 10-pin MSOP and 3mm 3mm PDAs MLF-10L package options with an operating junction tem- 802.11 WLAN power supplies perature range from 40C to 125C . RF power supplies Li Ion battery powered applications Typical Application Efficiency 4.7H vs. Output Current 3.3V 100 500mA MIC2204BMM 95 90 1 10 4.2V IN 85 3.6V 2.3V to 6V IN 2 9 80 SYNC IN 5V 4.7F IN 3 8 75 SYNC OUT 70 4 7 10nF 65 EN 5 6 60 55 3.3V OUT 50 0 100 200 300 400 500 OUTPUT CURRENT (mA) Adjustable Output Synchronous Buck Converter MLF and MicroLeadFrame are 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 MIC2204 Micrel, Inc. Ordering Information Part Number Voltage Junction Temp. Range Package Lead Finish MIC2204BMM Adjustable 40C to +125C 10-pin MSOP Standard MIC2204YMM Adjustable 40C to +125C 10-pin MSOP Lead-Free MIC2204BML Adjustable 40C to +125C 10-pin MLF Standard MIC2204YML Adjustable 40C to +125C 10-pin MLF Lead-Free Pin Configuration SW 1 10 GND VIN 2 9 GND SW 1 10 GND VIN 2 GND 9 SYNC IN 3 8 GND SYNC IN 3 8 GND SYNC OUT 4 7 BIAS SYNC OUT 4 7 BIAS EN 5 6 FB 56 EN FB MSOP-10 (MM) MLF-10 (ML) Pin Description Pin Number Pin Name Pin Function 1SW Switch (Output): Internal power MOSFET output switches. 2 VIN Supply Voltage (Input): Requires bypass capacitor to GND. 3 SYNC IN SYNC IN for the MIC2204: Sync the main switching frequency to an external clock. Tie pin to ground if not using this function. Tying SYNC IN high reduces the switching frequency to 1.6MHz (See Applications Informa- tion section). 4 SYNC OUT SYNC OUT an open collector output to feed into SYNC IN. Float or ground the SYNC OUT pin if not using sync out function. 5ENA low level EN will power down the device, reducing the quiescent current to under 15A (typ. 6.5A). 6FB Input to the error amplifier, connect to the external resistor divider network to set the output voltage. 7 BIAS Internal circuit bias supply, nominally 2.3V. Must be de-coupled to signal ground with a 0.01F capacitor. 8, 9, 10 GND Ground. M9999-042205 2 April 2005