MIC2168A 1MHz PWM Synchronous Buck-Control IC General Description Features The MIC2168A is a high-efficiency, simple to use 1MHz 3V to 14.5V input voltage range PWM synchronous buck-control IC housed in a small Adjustable output voltage down to 0.8V MSOP-10 package. The MIC2168A allows compact Up to 95% efficiency DC/DC solutions with a minimal external component count 1MHz PWM operation and cost. Adjustable current-limit senses high-side N-Channel The MIC2168A operates from a 3V to 14.5V input, without MOSFET current the need of any additional bias voltage. The output voltage No external current sense resistor can be precisely regulated down to 0.8V. The adaptive all Adaptive gate drive increases efficiency N-Channel MOSFET drive scheme allows efficiencies over 95% across a wide load range. Ultra-fast response with hysteretic transient recovery mode The MIC2168A senses current across the high-side N- Overvoltage protection protects the load in fault Channel MOSFET, eliminating the need for an expensive conditions and lossy current-sense resistor. Current limit accuracy is maintained by a positive temperature coefficient that tracks Dual mode current limit speeds up recovery time 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 Internal soft-start limiting and digital soft-start. Small-size MSOP 10-pin package The MIC2168A is identical to the MIC2168 with the exception that the MIC2168A increases the overcurrent blanking time from 80ns (typ.) to 120ns (typ.) Applications The MIC2168A is available in a 10-pin MSOP package, Point-of-load DC/DC conversion with a wide junction operating range of 40C to +125C. Set-top boxes Datasheets and support documentation are available on Graphic cards Micrels web site at: www.micrel.com. LCD power supplies Telecom power supplies Networking power supplies Cable modems and routers Typical Application Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC2168A Ordering Information Part Number Frequency Junction Temperature Range Package MIC2168AYMM 1MHz 40 to +125C 10-Pin MSOP Pb-Free Pin Configuration 10-Pin MSOP (MM) (Top View) Pin Description Pin Number Pin Name Pin Function 1 VIN Supply Voltage (Input): 3V to 14.5V. 5V Internal Linear Regulator (Output): VDD is the external MOSFET gate drive supply voltage 2 VDD and an internal supply bus for the IC. When VIN is <5V, this regulator operates in dropout mode. Current Sense / Enable (Input): Current-limit comparator noninverting input. The current limit is 3 CS sensed across the MOSFET during the ON time. The current can be set by the resistor in series with the CS pin. Compensation (Input): Dual function pin. Pin for external compensation. If this pin is pulled below 4 COMP 0.2V, with the reference fully up, the device shuts down (50A typical current draw). 5 FB Feedback (Input): Input to error amplifier. Regulates error amplifier to 0.8V. 6 GND Ground (Return). 7 LSD Low-Side Drive (Output): High-current driver output for external synchronous MOSFET. 8 VSW Switch (Return): High-side MOSFET driver return. High-Side Drive (Output): High-current output-driver for the high-side MOSFET. When VIN is 9 HSD between 3.0V to 5V, 2.5V threshold-rated MOSFETs should be used. At VIN > 5V, 5V threshold MOSFETs should be used. Boost (Input): Provides the drive voltage for the high-side MOSFET driver. The gate-drive voltage 10 BST is higher than the source voltage by VIN minus a diode drop. April 22, 2015 Revision 3.0 2