MIC4680 1A 200kHz SuperSwitcher Buck Regulator General Description Features The MIC4680 SuperSwitcher is an easy-to-use fixed or SOIC-8 package with up to 1.3A output current adjustable output voltage step-down (buck) switch-mode All surface mount solution voltage regulator. The 200kHz MIC4680 achieves up to Only 4 external components required 1.3A of continuous output current over a wide input range Fixed 200kHz operation in a 8-pin SOIC. 3.3V, 5V, and adjustable output versions The MIC4680 is available in 3.3V and 5V fixed output Internally compensated with fast transient response versions or adjustable output down to 1.25V. Wide 4V to 34V operating input voltage range The MIC4680 has an input voltage range of 4V to 34V, with excellent line, load, and transient response. The Less than 2A typical shutdown-mode current regulator performs cycle-by-cycle current limiting and Up to 90% efficiency thermal shutdown for protection under fault conditions. In Thermal shutdown shutdown mode, the regulator draws less than 2A of Overcurrent protection standby current. The MIC4680 SuperSwitcher regulator requires a mini- Applications mum number of external components and can operate using a standard series of inductors and capacitors. Simple 1A high-efficiency step-down (buck) regulator Frequency compensation is provided internally for fast Replacement of TO-220 and TO-263 designs transient response and ease of use. Efficient pre-regulator (5V to 2.5V, 12V to 3.3V, etc.) The MIC4680 is available in the 8-pin SOIC with a On-card switching regulators 40C to +125C junction temperature range. Positive-to-negative converter (inverting buck-boost) Simple battery charger Negative boost converter Higher output current regulator using external FET Typical Application MIC4680-3.3BM MIC4680BM L1 L1 +6V to +34V 3.3V/1A +5V to +34V 2.5V/1A 2 3 2 3 IN SW IN SW C1 C1 68H 68H R1 15F C2 15F C2 3.01k 35V 220F 35V 220F SHUTDOWN 1 4 SHUTDOWN 1 4 SHDN FB SHDN FB ENABLE ENABLE 16V 16V D1 D1 R2 GND B260A or GND B260A or Power Power 2.94k 58 SS26 58 SS26 SOIC-8 SOIC-8 Fixed Regulator Circuit Adjustable Regulator Circuit SuperSwitcher is a trademark of Micrel, Inc. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC4680 Ordering Information Part Number Voltage Junction Temp. Range Package Standard Pb-Free MIC4680BM MIC4680YM Adj. 40C to +125C 8-Pin SOIC MIC4680-3.3BM MIC4680-3.3YM 3.3V 40C to +125C 8-Pin SOIC MIC4680-5.0BM MIC4680-5.0YM 5.0V 40C to +125C 8-Pin SOIC Pin Configuration SHDN 1 8 GND IN 2 7 GND SW 3 6 GND FB 4 5 GND 8-Pin SIOC (M) Pin Description Pin Number Pin Name Pin Function 1 SHDN Shutdown (Input): Logic low enables regulator. Logic high (>1.6V) shuts down regulator. 2 VIN Supply Voltage (Input): Unregulated +4V to +34V supply voltage. 3 SW Switch (Output): Emitter of NPN output switch. Connect to external storage inductor and Shottky diode. 4 FB Feedback (Input): Connect to output on fixed output voltage versions, or to 1.23V-tap of voltage-divider network for adjustable version. 5 8 GND Ground M9999-032808 March 2008 2