MIC22705YML EV Evaluation Board 1MHz, 7A Integrated Switch HighEfficiency Synchronous Buck Regulator General Description The Micrel MIC22705 is a high-efficiency, 7A, integrated switch, synchronous buck (step-down) regulator. The MIC22705 achieves more than 95% efficiency and switches at 1MHz. The ultra-high speed control loop keeps the output voltage within regulation even under the extreme transient load swings commonly found in FPGAs and low-voltage ASICs. The output voltage is pre-bias safe and is adjustable down to 0.7V. The MIC22705 offers a full range of sequencing and tracking options. The Enable/Delay (EN/DLY) and Power Good (PG) inputs allow versatile turn-on and turn-off sequencing across multiple devices. The Ramp Control™ (RC) input allows start-up voltage tracking, either directly or ratio-metrically. The MIC22705 is available in a 24-pin 4mm x 4mm MLF® with a junction operating range from –40°C to +125°C. Data sheets and support documentation are found on the Micrel web site: www.micrel.com. Requirements The MIC22705YML EV requires a power supply of 2.9V to 5.5V, and a test load. Ensure that the power supply can provide the wattage required for the chosen test load. The load can be active (electronic load) or passive (resistor). Additionally, monitor the Power Good output (PG) with a multimeter or an oscilloscope if desired. Precautions There is no reverse input protection on this board. When connecting supplies and signals ensure that correct polarities are observed. Getting Started 1. VIN Supplies Connect the VIN supply (2.9V to 5.5V) across the PVIN and PGND terminals. Monitor VIN at the PVIN and PGND terminals with a voltmeter. 2. Enable/SHDN Inputs The enable input EN is internally pulled up with a 1µA current source. When external on/off control is desired, install Q1 and R5, and connect a logic level control signal to the SHDN input. When SHDN is high, the output is off, and when SHDN is low, the output is on. 3. Monitor Outputs Monitor the output VOUT with a scope or DVM connected across the VOUT and PGND terminals. 4. Output Load Connect a load across the VOUT and PGND terminals. Use an active or passive load. 5. Turn On the Power Turn on the power supply and verify that VOUT = 1.8V. Ordering Information Part Number Description MIC22705YML EV Evaluation Board for the MIC22705YML MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc. Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com February 2011 M9999-020411-A Micrel, Inc. MIC22705 Evaluation Board EV Board Features Ramp Control (RC) Ramp control allows slowing the slew rate of the MIC22705 output. Increase the value of capacitor C7 to reduce the slew rate. See the MIC22705YML datasheet for detailed explanations of these functions. Enable/Delay (EN/DLY) Enable/Delay allows delayed turn on of the MIC22705. Install a capacitor in location C6 to increase the start-up delay of the MIC22705. Power Good Output (PG) Open drain output PG pulls low when the output voltage of the MIC22705 is out of specification. PG is pulled up to VIN by a 47.5kΩ resistor. Shutdown Input (SHDN) SHDN allows enable/disable of the MIC22705 with an external logic signal. To activate the shutdown feature, install components into the locations labeled Q1 and R5 (component recommendations are listed in the Bill of Materials later in this document). With the components installed, force SHDN high to disable the MIC22705, and low to allow the MIC22705 to operate normally. Switch Voltage (VSW) Test point VSW is provided to monitor the internal switching node. VSW is isolated from the switch node by 49.9Ω resistor R6. Delay (DELAY) DELAY allows a delayed Power Good output (PG) indication. Install a capacitor in location C8 to increase the Power Good delay timing of the MIC22705. February 2011 2 M9999-020411-A Micrel, Inc. MIC22705 Evaluation Board Typical Characteristics IC Power Dissipation vs. Output Current (VIN = 3.3V) Efficiency (VIN = 3.3V) vs. Output Current 2 100 POWER DISSIPATION (W) V IN = 3.3V EFFICIENCY (%) 95 90 2.5V 85 1.8V 1.5V 80 VIN = 3.3V 1.2V 1.0V 0.9V 0.8V 75 70 0 1 2 3 4 5 6 7 8 1 0.5 0 0 9 2 4 6 OUTPUT CURRENT (A) OUTPUT CURRENT (A) February 2011 V OUT = 0.8V, 1.0V, 1.2V, 1.5V, 1.8V, 2.5V 1.5 3 M9999-020411-A Micrel, Inc. MIC22705 Evaluation Board Evaluation Board Schematic February 2011 4 M9999-020411-A Micrel, Inc. MIC22705 Evaluation Board Bill of Materials Item C1, C2, C3, C4 Part Number TDK 08056D226MAT AVX(2) GRM21BR60J226ME39L GRM188R7160J225M C1608X5R0J225M C13 C7 GRM188R71H103KA01D C9 L1 5 Murata AVX(2) 2.2µF/6.3V, Ceramic Capacitor, X5R, Size 0805 (3) Murata TDK 2.2µF/6.3V, Ceramic Capacitor, X7R, Size 0805 1 10nF, 0603, Ceramic Capacitor 1 (1) Murata(3) (4) Vishay 1nF, 0603, Ceramic Capacitor Murata(3) 1nF/50V, X7R, 0603, Ceramic Capacitor TDK (1) 1 1nF/50V, COG, 0603, Ceramic Capacitor Open GRM1555C1H390JZ01D Murata(3) VJ0402A390KXQCW1BC BC Components(5) GRM31CR60J476ME19 GRM31CC80G476ME19L C12 22µF/6.3V, 0805, Ceramic Capacitor Open(GRM188R71H102KA01D) C3216X5R0J476M C10, C11 Qty. (3) Open(VJ0603Y102KXQCW1BC) Open(C1608C0G1H102J) C6, C8 Description (1) C2012X5R0J226M 06036D225TAAT2A C5 Manufacturer 39pF/50V, COG, 0402, Ceramic Capacitor TDK(1) 47µF/6.3V, X5R, 1206, Ceramic Capacitor Murata(3) 47µF/6.3V, X5R, 1206, Ceramic Capacitor (3) 47µF/4V, X6S, 1206, Ceramic Capacitor (4) Murata VJ0402A101KXQCW1BC Vishay 100pF, 0603, Ceramic Capacitor GRM1555C1H101JZ01D Murata(3) 100pF/50V, COG, 0402, Ceramic Capacitor SPM6530T-1R0M120 TDK(1) 1 39pF /10V, 0402, Ceramic Capacitor 2 1 1µH, 12A, size 7x6.5x3mm (6) 1 HCP0704-1R0-R Coiltronics CIN BA1851A3477M Epcos(7) 470µF/10V, Elect., 8×11.5 1 R1 CRCW06031101FKEYE3 Vishay(4) Resistor, 1.10k, 0603, 1% 1 CRCW04026980FKEYE3 (4) Resistor, 698Ω, 0603, 1% 1 (4) Resistor, 47.5k, 0603, 1% 1 (4) R2 R3 CRCW06034752FKEYE3 1µH, 12A, size 6.8x6.8x4.2mm Vishay Vishay R4 CRCW04022002FKEYE3 Vishay Resistor, 20k, 0402, 1% 1 R5 Open(CRCW06031003FRT1) Vishay(4) Resistor, 100k, 0603, 1% 1 R6 CRCW060349R9FKEA Vishay(4) 49.9Ω Resistor, 1%, Size 0603 1 CRCW06032R20FKEA (4) 2.2Ω Resistor, 1%, Size 0603 1 Signal MOSFET − SOT23-6 1 1MHz, 7A Integrated Switch High-Efficiency Synchronous Buck Regulator 1 R7 Vishay Open(2N7002E) Q1 U1 Open(CMDPM7002A) MIC22705YML Central Semiconductor(8) Micrel, Inc.(6) Notes: 1. TDK: www.tdk.com. 2. AVX.: www.avx.com. 3. Murata: www.murata.com. 4. Vishay Tel: www.vishay.com. 5. BC Components: www.bccomponents.com. 6. Coiltronics: www.coiltronics.com. 7. Epcos: www.epcos.com. 8. Central Semiconductor: www.centralsemi.com. 9. Micrel, Inc.: www.micrel.com. February 2011 5 M9999-020411-A Micrel, Inc. MIC22705YML Evaluation Board Evaluation Board PCB Layout MIC22705 Evaluation Board Top Layer MIC22705 Evaluation Board Top Silk February 2011 6 M9999-020411-A Micrel, Inc. MIC22705YML Evaluation Board Evaluation Board PCB Layout (Continued) MIC22705 Evaluation Board Mid-Layer 1 (Ground Plane) MIC22705 Evaluation Board Mid-Layer 2 February 2011 7 M9999-020411-A Micrel, Inc. MIC22705YML Evaluation Board Evaluation Board PCB Layout (Continued) MIC22705 Evaluation Board Bottom Layer MIC22705 Evaluation Board Bottom Silk February 2011 8 M9999-020411-A Micrel, Inc. MIC22705YML Evaluation Board MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2011 Micrel, Incorporated. February 2011 9 M9999-020411-A