MIC22205 Evaluation Board 2A Integrated Switch High-Efficiency Synchronous Buck Regulator General Description Getting Started The Micrel MIC22205 is a high-efficiency, 2A, integrated switch, synchronous buck (step-down) regulator. It is frequency programmable up to 4MHz. The MIC22205 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 MIC22205 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 MIC22205 is available in a 12-pin 3mm x 3mm ® MLF with a junction operating range from –40°C to +125°C. Data sheets and support documentation are available on the Micrel web site: www.micrel.com. Requirements The MIC22205YML EV requires a power supply of 2.9V to 5.5V, and a test load. Make sure that the power supply can provide the wattage needed 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. Precautions There is no reverse input protection on this board. While connecting supplies and signals, make sure that correct polarities are observed. 1. VIN Supplies Connect the VIN supply (2.9V to 5.5V) across the VIN and PGND terminals. Monitor VIN at the VIN and PGND terminals with a voltmeter. TP9 is a 4-pin header test point provided for monitoring VIN. 2. Enable The enable input EN is internally pulled up with a 1µA current source. 3. Monitor Outputs Monitor the output VOUT with a scope or DVM connected across the VOUT and PGND terminals. TP11 is a 4-pin header test point provided for monitoring VOUT. 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 MIC22205YML EV Evaluation Board for the MIC22205YML Ramp Control is a trademark of Micrel, Inc. 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 September 2012 M9999-092112-A Micrel, Inc. MIC22205 Evaluation Board Evaluation Board Features Ramp Control (RC) Ramp control allows slowing the slew rate of the MIC22205 output. Increase the value of capacitor C6 to reduce the slew rate. See the MIC22205YML Data Sheet for detailed explanations of these functions. Enable/Delay (EN/DLY) Enable/Delay allows delayed turn-on of the MIC22205. Install a capacitor in location C7 to increase the start-up delay of the MIC22205. t EN/DLY = t RAMP = 1.24 × C 7 1 × 10 − 6 September 2012 0.7 × C 6 1 × 10 − 6 Power On Reset Output (POR) Open drain output POR pulls low when the output voltage of the MIC22205 is out of specification. POR is pulled up to VIN by a 47.5kΩ resistor. 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. TP10 is a 2-pin header test point provided for monitoring switch voltage. 2 M9999-092112-A Micrel, Inc. MIC22205 Evaluation Board Typical Characteristics Efficiency (VIN = 5.0V) vs. Output Current IC Power Dissipation (VIN = 5.0V) vs. Output Current 0.72 100 3.3V OUT 90 EFFICIENCY (%) POWER DISSIPATION (W) 95 2.5V OUT 1.8V OUT 1.5V OUT 1.2V OUT 1.0V OUT 85 80 75 70 0.9V OUT 0.8V OUT 65 VIN = 5V 60 0.7V OUT 55 50 0.60 0.48 Curves Top to Bottom 3.3V OUT 0.36 1.2V OUT 0.7V OUT 0.24 0.12 0.00 0 0.6 1.2 1.8 2.4 3 0 OUTPUT CURRENT (A) September 2012 0.4 0.8 1.2 1.6 2 OUTPUT CURRENT (A) 3 M9999-092112-A Micrel, Inc. MIC22205 Evaluation Board Evaluation Board Schematic Bill of Materials Item Part Number C2012X5R0J106K C1 GRM2196R60J106K 08056D106KAT2A C2 06036D225MAT2A AVX C6 C7, C8 GQM1885C1H470JB01D TDK TDK Murata 06035A221JAT2A AVX C1608C0G1H102J TDK September 2012 1 Capacitor, 470pF, 50V, X7R, Size 0603 Murata C1608C0G1H221J 06035A102KAT2A Capacitor, 2.2µF, 6.3V, X5R, Size 0603 AVX AVX GRM1885C1H102JA01D 1 TDK Murata 06035A470JAT2A GRM1885C1H221JA01D Capacitor, 10µF, 6.3V, X5R, Size 0805 AVX Murata C1608C0G1H470J Qty. (3) GRM188R60J225M 06035C471KAT2A C5 Murata(2) TDK GRM188R71H471KA01D Description TDK(1) C1608X5R0J225M C1608X7RH471K C3 Manufacturer Murata Capacitor, 47pF, 50V, NPO, Size 0603 1 Capacitor, 220pF, 50V, NPO, Size 0603 1 Capacitor, 1nF, 50V, NPO, Size 0603 2 AVX 4 M9999-092112-A Micrel, Inc. MIC22205 Evaluation Board Bill of Materials (Continued) Item C9 Part Number GRM31CR60J476ME19L 1206D476MAT2A C1608C0G1H101J C11 Description Qty. D.N.P. C3216X5R0J476M C10 Manufacturer GRM1885C1H101JA01D 06035A101JAT2A TDK Murata Capacitor, 47µF, 6.3V, X5R, Size 1206 1 Capacitor, 100pF, 50V, NPO Size 0603 1 AVX TDK Murata AVX C12 B41125A3477M Epcos(4) 470µF, 10V, Electrolytic, 8x10 case 1 L1 IHLP1616BZER1R0M11 Vishay(5) Inductor, 1µH, 5A 1 R1 CRCW06031602FKEA Resistor, 16K, 1%, Size 0603 1 R2, R3 CRCW06031002FKEA AVX Resistor, 10K, 1%, Size 0603 2 R4 CRCW060320K0FKEA AVX Resistor, 20K, 1%, Size 0603 1 R5 CRCW06032R20FKEA AVX Resistor, 2.2Ω, 1%, Size 0603 1 R6 CRCW060349R9FKEA AVX Resistor, 49.9Ω, 1%, Size 0603 1 Integrated 2A Synchronous Buck Regulator 1 U1 MIC22205YML AVX Micrel (6) Notes: 1. TDK: www.tdk.com. 2. Murata: www.murata.com. 3. AVX: www.avx.com. 4. Epcos: www.epcos.com. 5. Vishay: www.vishay.com. 6. Micrel, Inc.: www.micrel.com. September 2012 5 M9999-092112-A Micrel, Inc. MIC22205 Evaluation Board Evaluation Board PCB Layout MIC22205 Evaluation Board Top Layer MIC22205 Evaluation Board Top Silk September 2012 6 M9999-092112-A Micrel, Inc. MIC22205 Evaluation Board Evaluation Board PCB Layout (Continued) MIC22205 Evaluation Board Bottom Layer MIC22205 Evaluation Board Bottom Silk September 2012 7 M9999-092112-A Micrel, Inc. MIC22205 Evaluation Board MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB 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. © 2012 Micrel, Incorporated. September 2012 8 M9999-092112-A