MIC22405YML EV Evaluation Board 4A Integrated Switch High-Efficiency Synchronous Buck Regulator with Frequency Programmable upto 4MHz General Description The Micrel MIC22405 is a high-efficiency, 4A, integrated switch, synchronous buck (step-down) regulator. The MIC22405 achieves more than 95% efficiency and switches at 1MHz. The ultra-high speed control loop keeps the output voltage within regulation even under extreme transient load swings commonly found in FPGAs and lowvoltage ASICs. The output voltage is pre-bias safe and is adjustable down to 0.7V. The MIC22405 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 MIC22405 is available in a 20-pin 3mm x 4mm MLF with a junction operating range from –40°C to +125°C. ® Getting Started 1. VIN Supplies Connect the VIN supply (2.9V to 5.5V) across the VIN and GND terminals. Monitor VIN at the VIN and GND 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 GND terminals. 4. Output Load Connect a load across the VOUT and GND terminals. Use an active or passive load. 5. Turn On the Power Turn on the power supply and verify that VOUT = 1.8V. Data sheets and support documentation are found on the Micrel web site: www.micrel.com. Requirements The MIC22405YML 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. Ordering Information Part Number Description MIC22405YML EV Evaluation Board for the MIC22405YML Precautions There is no reverse input protection on this board. While connecting supplies and signals ensure that correct polarities are observed. Ramp Control is a trademark of Micrel, 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 July 2011 M9999-071911-B Micrel, Inc. MIC22405 Evaluation Board Evaluation Board Features Ramp Control (RC) Ramp control allows slowing the slew rate of the MIC22405 output. Increase the value of capacitor C6 to reduce the slew rate. Enable/Delay (EN/DLY) Enable/Delay allows delayed turn on of the MIC22405. Install a capacitor in location C4 to increase the start-up delay of the MIC22405. Power Good Output (PG) Open drain output PG pulls low when the output voltage of the MIC22405 is out of specification. PG is pulled up to VIN by a 47.5kΩ resistor. Shutdown Input (SHDN) SHDN allows enable/disable of the MIC22405 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 MIC22405, and low to allow the MIC22405 to operate normally. July 2011 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 R7. 2 M9999-071911-B Micrel, Inc. MIC22405YML Evaluation Board Typical Characteristics Efficiency (VIN = 3.3V) vs. Output Current 100 1.25 POWER DISSIPATION (W) EFFICIENCY (%) 95 90 2.5V 1.8V 1.5V 1.2V 1.0V 0.9V 0.8V 0.7V 85 80 75 70 VIN = 3.3V 65 2.5V 1.8V 1.5V 1.2V 1.0V 0.9V 0.8V 0.7V 1.00 0.75 0.50 0.25 VIN = 3.3V 0.00 0 1 2 3 4 5 0 6 OUTPUT CURRENT (A) July 2011 IC Power Dissipation (VIN = 3.3V) vs. Output Current 1 2 3 4 OUTPUT CURRENT (A) 3 M9999-071911-B Micrel, Inc. MIC22405YML Evaluation Board Functional Characteristics Efficiency (VIN = 3.3V) vs. Output Current 100 1.25 POWER DISSIPATION (W) EFFICIENCY (%) 95 90 2.5V 1.8V 1.5V 1.2V 1.0V 0.9V 0.8V 0.7V 85 80 75 70 VIN = 3.3V 65 2.5V 1.8V 1.5V 1.2V 1.0V 0.9V 0.8V 0.7V 1.00 0.75 0.50 0.25 VIN = 3.3V 0.00 0 1 2 3 4 5 0 6 OUTPUT CURRENT (A) July 2011 IC Power Dissipation (VIN = 3.3V) vs. Output Current 1 2 3 4 OUTPUT CURRENT (A) 4 M9999-071911-B Micrel, Inc. MIC22405YML Evaluation Board Evaluation Board Schematic Bill of Materials Item C1, C2 Part Number AVX C2012X5R0J226M TDK(2) AVX(2) GRM188R60J225M Murata(3) C1608X5R0J225M C4, C12 C1608C0G1H102J 06035C102KAT2A GRM188R71H471KA01D C6 C1608X7RH471K 06035C471KAT2A GRM188R71H390JA01 C7 C1608COG1H390J 06035A390JAT2A GRM188R71H391JA01 C8 July 2011 Qty. Capacitor, 22µF, 6.3V, X5R, Size 0805 2 Murata(3) 06036D225MAT2A GRM188R71H102KA01D Description (1) 08056D226MAT GRM21BR60J226ME39L C3 Manufacturer TDK Murata(3) TDK 2.2µF/6.3V, Ceramic Capacitor, X5R, Size 0603 1 (1) Capacitor, 1nF, 50V, X7R, Size 0603 (2) (1) AVX Capacitor, 1nF, 10V, COG, Size 0603 2 Murata(3) TDK(2) Capacitor, 470pF, 50V, X7R, Size 0603 1 Capacitor, 39pF, 50V, Size 0603 1 Capacitor, 390pF, 50V, Size 0603 1 (1) AVX Murata(3) TDK(2) (1) AVX Murata(3) 1608COG1H391J TDK(2) 06035A391JAT2A (1) AVX 5 M9999-071911-B Micrel, Inc. MIC22405YML Evaluation Board Bill of Materials (Continued) Item Part Number GRM188R71H101JA01 C9 C1608COG1H101J 06035A101JT2A GRM31CR60J476ME19 C10, C11 Cin L1 Manufacturer Qty. Murata TDK(2) Capacitor, 100pF, 50V, Size 0603 1 Capacitor, 47µF, 6.3V, X5R, Size 1206 2 (1) AVX Murata(3) C3216X5R0J476M TDK(2) 12066D476MAT2A (1) AVX B41125A3477M Epcos (5) FP3-1R0-R( 7.2x6.7x3mm ) Cooper CDRH8D28NP-1R0NC ( 8x6x3mm ) Sumida(6) SPM6530T-1R0M120 ( 7x6.5x3mm ) Description (3) (2) TDK (4) 470µF, 10V, Electrolytic, 8x10-case Inductor, 1µH, 6.26A 1 Inductor, 1µH, 8A 1 Inductor, 1µH, 12A 1 R1 CRCW06031101FKEYE3 Vishay Resistor, 1.1k, 1%, Size 0603 1 R2 CRCW06036980FKEYE3 Vishay(4) Resistor, 698Ω, 1%, Size 0603 1 R3 CRCW06032002FKEYE3 Vishay(4) Resistor, 20k, 1%, Size 0603 1 CRCW06034752FKEYE3 (4) Resistor, 47.5k, 1%, Size 0603 1 (4) R4 Vishay R5 (Open) CRCW06031003FKEYE3 Vishay Resistor, 100k, 1%, Size 0603 1 R6 CRCW06032R20FKEA Vishay(4) Resistor, 2.2Ω, 1%, Size 0603 1 R7 CRCW060349R9FKEA Vishay(4) Resistor, 49.9Ω, 1%, Size 0603 1 (4) Q1 2N7002E Vishay Open 1 U1 MIC22405YML Micrel(7) Integrated 4A Synchronous Buck Regulator 1 Notes: 1. AVX: www.avx.com 2. TDK: www.tdk.com 3. Murata: www.murata.com 4. Vishay: www.vishay.com 5. Cooper Bussmann: www.cooperet.com 6. Sumida: www.sumida.com 7. Micrel, Inc.: www.micrel.com July 2011 6 M9999-071911-B Micrel, Inc. MIC22405YML Evaluation Board Evaluation Board PCB Layout MIC22405 Evaluation Board Top Layer MIC22405 Evaluation Board Top Silk July 2011 7 M9999-071911-B Micrel, Inc. MIC22405YML Evaluation Board Evaluation Board PCB Layout (Continued) MIC22405 Evaluation Board Mid-Layer 1 (Ground Plane) MIC22405 Evaluation Board Mid-Layer 2 July 2011 8 M9999-071911-B Micrel, Inc. MIC22405YML Evaluation Board Evaluation Board PCB Layout (Continued) MIC22405 Evaluation Board Bottom Layer MIC22405 Evaluation Board Bottom Silk July 2011 9 M9999-071911-B Micrel, Inc. MIC22405YML 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. © 2010 Micrel, Incorporated. July 2011 10 M9999-071911-B