MIC2169BYMME Microchip

MIC2169B 500kHz PWM Synchronous Buck Control IC General Description Features The MIC2169B is a high-efficiency, simple to use 500kHz 3V to 14.5V input voltage range PWM synchronous buck control IC housed in small Adjustable output voltage down to 0.8V MSOP-10 and MSOP-10 ePad packages. The MIC2169B 500kHz PWM operation allows compact DC/DC solutions with a minimal external Up to 95% efficiency component count and cost. The device features high- output driver capability to drive loads up to 30A. Output Pre-biased Protection The MIC2169B operates from a 3V to 14.5V input, without Build-in 2.2 drivers to drive two n-channel MOSFETs the need of any additional bias voltage. The output voltage Adaptive gate drive increases efficiency can be precisely regulated down to 0.8V. The adaptive all Simple, externally-compensated voltage-mode PWM N-Channel MOSFET drive scheme allows efficiencies over control 95% across a wide load range within the smallest possible Short minimum ON time of 30ns allowing very-low duty printed circuit board space area. cycle The MIC2169B senses current across the high-side N- Fast transient response Channel MOSFET, eliminating the need for an expensive Adjustable current limit senses high-side N-Channel and lossy current-sense resistor. Current-limit accuracy is MOSFET current maintained by a positive temperature coefficient that tracks the increasing R of the external MOSFET. Further DS(ON) Hiccup mode short-circuit protection cost and space are saved by the internal in-rush current- No external current-sense resistor limiting digital soft-start. The MIC2169B is identical to the Internal soft-start current source MIC2169A with the exception that the MIC2169B supports Dual function COMP and EN pin allows low-power pre-bias loads and has a lower impedance gate-drive shutdown circuit. Internal pre-bias circuit prevents output voltage drooping and excessive reverse inductor current when Available in small-size 10-pin MSOP and 10-pin MSOP powering up with a pre-bias voltage at the output. ePad packages The MIC2169B is available in a 10-pin MSOP and a Applications thermally-capable 10-pin ePad MSOP package, with a Point-of-load DC/DC conversion wide junction operating range of -40C to +125C. High-Current Power Supplies All support documentation can be found on Micrels web Telecom/Datacom and Networking Power Supplies site at www.micrel.com. Servers and Workstations Graphic cards and other PC Peripherals Set-top boxes LCD power supplies Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC2169B Typical Application V = 5V to 12V IN MIC2169B Efficienc SD103BWS 100 100F 10F 95 0.1F 10F 90 0.1F 85 VDD BST 80 CS 75 IRF7821 70 VIN HSD 1.0H 3.3V MIC2169B 65 VSW 60 V =5V IN COMP/EN IRF7821 150pF LSD V =3.3V 100nF 55 OUT 1000pF 1F 330F x 2 50 FB 02 46 8 10121416 GND EP I (A) LOAD MIC2169B Adjustable Output 500kHz Converter April 2010 2 M9999-041210-B EFFICIENCY (%)