MIC2193 Micrel MIC2193 400kHz SO-8 Synchronous Buck Control IC General Description Features Micrels MIC2193 is a high efficiency, PWM synchronous 2.9V to 14V input voltage range buck control IC housed in the SO-8 package. Its 2.9V to 14V 400kHz oscillator frequency input voltage range allows it to efficiently step down voltages PWM current mode control in 3.3V, 5V, and 12V systems as well as 1- or 2-cell Li Ion 100% maximum duty cycle battery powered applications. Front edge blanking 4 output drivers The MIC2193 solution saves valuable board space. The Cycle-by-cycle current limiting device is housed in the space-saving SO-8 package, whose Frequency foldback short circuit protection low pin-count minimizes external components. Its 400kHz 8 lead SOIC package PWM operation allows a small inductor and small output capacitors to be used. The MIC2193 can implement all- Applications ceramic capacitor solutions. Point of load power supplies The MIC2193 drives a high-side P-channel MOSFET, elimi- Distributed power systems nating the need for high-side boot-strap circuitry. This feature Wireless Modems allows the MIC2193 to achieve maximum duty cycles of ADSL line cards 100%, which can be useful in low headroom applications. A Servers low output driver impedance of 4 allows the MIC2193 to Step down conversion in 3.3V, 5V, and 12V systems drive large external MOSFETs to generate a wide range of 1-and 2-cell Li Ion battery operated equipment output currents. The MIC2193 is available in an 8 pin SOIC package with a junction temperature range of 40C to +125C. Typical Application V IN 3.3V 0.012 120 F MIC2193BM Si9803 6.3V (2) (2) VIN CS V OUT 1.8V, 5A VDD OUTP 3.8 H 2k COMP OUTN Si9804 10k (2) 220 F 1 F GND FB 6.3V (2) 2.2nF 22.6k Adjustable Output Synchronous Buck Converter Micrel, Inc. 1849 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 474-1000 MIC2193 Micrel Ordering Information Part Number Voltage Frequency Temperature Range Package Lead Finish MIC2193BM Adjustable 400KHz 40C to +125C 8-lead SOP Standard MIC2193YM Adjustable 400KHz 40C to +125C 8-lead SOP Pb-Free Pin Configuration VIN 1 8 OUTP COMP 2 7 OUTN FB 3 6 GND CS 4 5 VDD 8 Lead SOIC (M) Pin Description Pin Number Pin Name Pin Function 1 VIN Controller supply voltage. Also the (+) input to the current sense amp. 2 COMP Compensation (Output): Internal error amplifier output. Connect to a capacitor or series RC network to compensate the regulators control loop. 3 FB Feedback Input: The circuit regulates this pin to 1.245V. 4 CS The () input to the current limit comparator. A built in offset of 110mV between VIN and CSL in conjunction with the current sense resistor sets the current limit threshold level. This is also the () input to the current amplifier. 5 VDD 3V internal linear-regulator output. VDD is also the supply voltage bus for the chip. Bypass to GND with 1 F. 6 GND Ground. 7 OUTN High current drive for the synchronous N-channel MOSFET. Voltage swing is from ground to VIN. On-resistance is typically 6 at 5V . IN 8 OUTP High current drive for the high side P-channel MOSFET. Voltage swing is from ground to VIN. On-resistance is typically 6 at 5V . IN M9999-042704 2 April 2004