MIC2166 Adaptive On-Time DC-DC Controller Hyper Speed Control Family General Description Features The Micrel MIC2166 is a synchronous adaptive on-time Hyper Speed Control architecture enables buck controller targeting high-performance, cost-sensitive - High delta V operation (V =28V and V =0.8V) IN OUT applications such as set-top boxes, gateways, routers, - Small output capacitance computing peripherals, and telecom/networking Built-in 5V regulator for single-supply operation equipment. TM Any Capacitor stable The MIC2166 operates over a supply range of 4.5V to - Zero ESR to high ESR 28V. It has an internal linear regulator which provides a regulated 5V supply to power the internal control circuitry. Power-Good (PGOOD) output MIC2166 operates at a constant 600kHz switching Input voltage range: 4.5V to 28V frequency and can be used to drive up to 25A of output 5 A typical shutdown current current. The output voltage is adjustable from 0.8V to 25A output current drive capability 5.5V. Adjustable output from 0.8V to 5.5V with 1% FB A unique Hyper Speed Control architecture enables accuracy ultra-fast transient response while reducing the output 600kHz switching frequency capacitance and also makes High V /Low V operation IN OUT possible. Internal 5ms digital soft-start A UVLO feature is provided to ensure proper operation Thermal-shutdown and hiccup current-limit protection under power-sag conditions to prevent the external power No external current-sense resistor required MOSFET from over heating. Also, a soft-start feature is Safe start-up into pre-biased loads provided to reduce the inrush current. Short current 10-pin MSOP ePad package sensing on the bottom MOSFET with hiccup mode current limiting ensures protection in case of an output short 40 C to +125 C junction temperature range circuit. Further, the MIC2166 includes an EN pin to shut Applications down the converter and a Power-Good (PGOOD) pin to allow simple sequencing. Set-top box, gateways, routers and DSL modems The MIC2166 is available in a 10 pin MSOP ePad package Printers, scanners, graphic and video cards with a junction operating temperature ranging from 40 C Servers, PCs and processor core supply to +125 C. All support documentation can be found on Low-Voltage Distributed Power Micrels web site at: www.micrel.com. Typical Application 12V to 3.3V Efficiency 100 90 80 70 60 50 40 30 20 10 0 0 123 45 678 9 10 OUTPUT CURRENT (A) MIC2166 Adjustable Output 600kHz Buck Converter MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc. Hyper Light Load and Any Capacitor are trademarks of Micrel, Inc. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC2166 Ordering Information Part Number Voltage Switching Frequency Junction Temperature Range Package Lead Finish MIC2166YMME Adjustable 600kHz 40 to +125C 10-pin ePad MSOP Pb-Free Pin Configuration 10-Pin ePad MSOP (MME) Pin Description Pin Pin Name Pin Function Number Feedback (Input): Input to the transconductance amplifier of the control loop. The FB pin is regulated to 1 FB 0.8V. A resistor divider the output an FB is used to set the desired output voltage. Power Good (Output): Open Drain Output. The PGOOD pin is externally tied with a resistor to VDD. 2 PGOOD High output when V >90% nominal. OUT Enable (Input): A logic level control of the output. The EN pin is CMOS-compatible. Logic high = enable, logic low = shutdown. In the off state, supply current of the device is greatly reduced (typically 5A). The 3 EN EN pin should not be left open. Connect to VIN if sequencing is not required. Supply Voltage: Input voltage for the internal +5V linear regulator. The VIN operating voltage range is 4 VIN from 4.5V to 28V. A 0.1F capacitor between VIN and the ground is required. 5V Internal Linear Regulator (Output): VDD is the external MOSFET gate drive supply voltage and an VDD internal supply bus for the IC. VDD is created by internal LDO from VIN. When VIN <+5.5V, VDD Should 5 be tied to VIN. A 2.2F (minimum) ceramic capacitor from VDD to GND is recommended for clean operation. Low-Side Gate Drive (Output): High-current driver output for external low-side MOSFET. The DL driving 6 DL voltage swings from ground to VDD. Power Ground. PGND is the ground path for the MIC2166 buck converter power stage. The PGND pin connects to the sources of low-side N-Channel MOSFETs, the negative terminals of input capacitors, 7 PGND and the negative terminals of output capacitors. The loop for the power ground should be as small as possible and separate from the Signal ground (GND) loop. High-Side Gate Drive (Output): High-current driver output for external high-side MOSFET. The DH driving voltage is floating on the switch node voltage (SW). It swings from ground-to-VDD minus the 8 DH diode drop. 2 September 2010 M9999-092410-C