MIC2193BM-TR

MIC2193 Micrel MIC2193 400kHz SO-8 Synchronous Buck Control IC General Description Features Micrel’s MIC2193 is a high efficiency, PWM synchronous buck control IC housed in the SO-8 package. Its 2.9V to 14V input voltage range allows it to efficiently step down voltages in 3.3V, 5V, and 12V systems as well as 1- or 2-cell Li Ion battery powered applications. The MIC2193 solution saves valuable board space. The device is housed in the space-saving SO-8 package, whose low pin-count minimizes external components. Its 400kHz PWM operation allows a small inductor and small output capacitors to be used. The MIC2193 can implement allceramic capacitor solutions. The MIC2193 drives a high-side P-channel MOSFET, eliminating the need for high-side boot-strap circuitry. This feature allows the MIC2193 to achieve maximum duty cycles of 100%, which can be useful in low headroom applications. A low output driver impedance of 4Ω allows the MIC2193 to drive large external MOSFETs to generate a wide range of output currents. The MIC2193 is available in an 8 pin SOIC package with a junction temperature range of –40°C to +125°C. • • • • • • • • • 2.9V to 14V input voltage range 400kHz oscillator frequency PWM current mode control 100% maximum duty cycle Front edge blanking 4Ω output drivers Cycle-by-cycle current limiting Frequency foldback short circuit protection 8 lead SOIC package Applications • • • • • • • Point of load power supplies Distributed power systems Wireless Modems ADSL line cards Servers Step down conversion in 3.3V, 5V, and 12V systems 1-and 2-cell Li Ion battery operated equipment Typical Application VIN 3.3V 0.012Ω 120µF 6.3V (×2) MIC2193BM VIN VDD 2k 1µF CS OUTP COMP OUTN GND FB Si9803 (×2) VOUT 1.8V, 5A 3.8µH Si9804 (×2) 10k 22.6k 2.2nF 220µF 6.3V (×2) 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 • http://www.micrel.com April 2004 1 M9999-042704 MIC2193 Micrel Ordering Information Part Number Voltage Frequency Temperature Range Package Lead Finish MIC2193BM Adjustable 400KHz –40°C to +125°C 8-lead SOP Standard MIC2193YM Adjustable 400KHz –40°C to +125°C 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 1 VIN 2 COMP 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 1µF. 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 6Ω at 5VIN. 8 OUTP High current drive for the high side P-channel MOSFET. Voltage swing is from ground to VIN. On-resistance is typically 6Ω at 5VIN. M9999-042704 Pin Function Controller supply voltage. Also the (+) input to the current sense amp. Compensation (Output): Internal error amplifier output. Connect to a capacitor or series RC network to compensate the regulator’s control loop. 2 April 2004 MIC2193 Micrel Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Supply Voltage (VIN) ..................................................... 15V Digital Supply Voltage (VDD) ........................................... 7V Comp Pin Voltage (VCOMP) ............................ –0.3V to +3V Feedback Pin Voltage (VFB) .......................... –0.3V to +3V Current Sense Voltage (VIN – VCS) ................ –0.3V to +1V Power Dissipation (PD) ..................... 285mW @ TA = 85°C Ambient Storage Temp ............................ –65°C to +150°C ESD Rating Note 3 ....................................................... 2kV Supply Voltage (VIN) .................................... +2.9V to +14V Junction Temperature ....................... –40°C ≤ TJ ≤ +125°C Package Thermal Resistance θJA 8-lead SOP ................................................. 140°C/W Electrical Characteristics VIN = 5V, VOUT = 3.3V, TJ = 25°C, unless otherwise specified. Bold values indicate –40°C