MIC4690 Micrel MIC4690 500kHz 1A SuperSwitcher Buck Regulator General Description Features The MIC4690 SuperSwitcher is an easy-to-use, 500kHz SO-8 package with over 1A output current step-down PWM voltage regulator. The MIC4690 achieves Fixed 500kHz operation over 1A of continuous output current over a wide input voltage Wide 4V to 34Vinput voltage range range in an 8-lead SO (small outline) package. Output voltage adjustable to 1.23V All surface mount solution The high switching frequency of the MIC4690 allows the Internally compensated with fast transient response smallest surface-mount inductors and capacitors to be used. Up to 85% efficiency Internal compensation ensures fast transient response and a Overcurrent protection minimum amount of external components. Frequency foldback short-circuit protection The MIC4690 features a power SO-8 package with a special Thermal shutdown lead frame that allows over 1A of continuous current. The Applications MIC4690, housed in an SO-8, can replace larger TO-220 and TO-263 packages in many applications. Simple 1A step-down (buck) regulator The MIC4690 allows for a high degree of safety. It has a wide Replacement of TO-220 and TO-263 designs input voltage range of 4V to 34V, allowing for it to be used in 12V to 5V/3.3V/2.5V/1.8V/1.5V conversion applications where input voltage transients may be present. 5V to 2.5V/1.8V/1.5V conversion Built-in safety features include over-current protection, fre- On-card switching regulators quency foldback protection, and thermal shutdown. Hard disk drives Cable modems The MIC4690 is available in an 8-lead SO package with a Positive-to-negative converters junction temperature range of 40C to +125C. Simple battery chargers Typical Application Power SOP-8 2.5V Adjustable Converter % Power SOP-8 & ( ( )* 1.8V Adjustable Converter 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 MIC4690 Micrel Ordering Information Part Number Standard Lead-Free Voltage Temperature Range Package MIC4690BM MIC4690YM Adjustable 40C to +125C 8-lead SOP Pin Configuration SHDN 1 8 GND VIN 2 7 GND SW 3 6 GND FB 4 5 GND SOP-8 (M) Pin Description Pin Number Pin Name Pin Function 1 SHDN Shutdown (Input): Logic low enables regulator. Logic high (>1.5V) shuts down regulator. 2 VIN Supply Voltage (Input): Unregulated +4V to +30V continuous supply voltage, with a maximum +34V transient voltage. 3 SW Switch (Output): Emitter of NPN output switch. Connect to external storage inductor and Schottky 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 MIC4690 2 April 2005