MIC2176 5A Evaluation Board High Input Voltage, Synchronous Buck Controllers Featuring Adaptive On-Time Control Hyper Speed ControlTM Family General Description The Micrel MIC2176-1/-2/-3 is a family of constantfrequency, synchronous buck controllers featuring a unique digitally modified adaptive ON-time control architecture. The MIC2176 family operates over an input supply range of 4.5V to 75V. The output voltage is adjustable down to 0.8V with a guaranteed accuracy of ±1%, and the device operates at a switching frequency of 100kHz, 200kHz, and 300kHz. Data sheets and other support documents can be found on Micrel’s web site at: www.micrel.com. Requirements The MIC2176 evaluation board requires only a single power supply with at least 10A current capability. A linear regulator, which includes a Zener and an NPN transistor, has been installed on the board to provide housekeeping for the MIC2176 controller. The output load can either be a passive or an active load. Precautions The MIC2176 evaluation board does not have reverse polarity protection. Applying a negative voltage to the VIN and GND terminals may damage the device. The maximum VIN of the board is rated at 75V. Exceeding 75V on the VIN terminal could damage the device. Getting Started 1. Connect a supply to the VIN and GND terminals. Apply desired input voltage to the VIN and GND terminals of the evaluation board, paying careful attention to polarity and supply voltage (4.5V < VIN < 75V). A current meter may be placed between the input supply and the VIN terminal of the evaluation board. Ensure the supply voltage is monitored at the VIN terminal. At heavy loads, the current meter, wires, and power lead could have voltage drops that reduce the voltage applied to the input. 2. Connect a load to the VOUT and GND terminals. The load can be either a passive (resistive) or an active (as in an electronic load) type. A current meter can be placed between the VOUT terminal and the load. Ensure the output voltage is monitored at the VOUT terminal. 3. Enable the MIC2176. An EN connector is provided on the MIC2176 evaluation board for the users to easily access the enable feature of the MIC2176 controller. The EN pin has an internal 100k pull-up resistor to VDD, which allows the output to be turned on when VDD exceeds its UVLO threshold. Applying an external logic signal on the EN pin to pull it low or using a jumper to short the EN pin to GND will shut off the output of the MIC2176 evaluation board. Output Voltage The output voltage on the MIC2176 evaluation board is preset to 3.3V. The final output voltage is determined by the feedback divider as calculated as follows: VOUT = VREF × (1+ R R1 ) BOTTOM where VREF = 0.8V, and RBOTTOM is one of R4, R5, R6, R7, R8, R9, R10, R11, which corresponds to 0.9V, 1.0V, 1.2V, 1.5V, 1.8V, 2.5V, 3.3V, or 5V output voltage. Leaving the RBOTTOM open gives a 0.8V output voltage. All other voltages not listed above can be set by modifying RBOTTOM value according to: R BOTTOM = R1× VREF VOUT − VREF Note that the output voltage should not be set to exceed 5V due to the 6.3V voltage rating on the output capacitors. If a higher than 5V output voltage is desired, those output capacitors have to be replaced with higher rating ones. Ordering Information Part Number Description Package MIC2176-1YMM IC, 100kHz 10-Pin MSOP MIC2176-2YMM IC, 200kHz 10-Pin MSOP IC, 300kHz 10-Pin MSOP MIC2176-3YMM MIC2176-2YMM 5A EV Evaluation Board Hyper Speed 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 November 2010 M9999-111710 Micrel, Inc. MIC2176 5A Evaluation Board Evaluation Board Schematic Schematic of MIC2176 Evaluation Board (J1, J9, J12, R12, and R13 are for testing purposes) November 2010 2 M9999-111710 Micrel, Inc. MIC2176 5A Evaluation Board Bill of Materials Item C1 Part Number B41125A9336M C2, C3 C4 GRM32ER72A225K 6SEPC470M Manufacturer Description (1) EPCOS 33µF Aluminum Capacitor, SMD, 100V 1 (2) 2.2µF/100V Ceramic Capacitor, X7R, Size 1210 2 (3) 470µF/6.3V OSCON Capacitor 1 (2) Murata Sanyo Qty C5, C15 GRM32ER60J104KA94D Murata 100µF/6.3V Ceramic Capacitor, X7R, Size 1210 2 C6, C7, C16 GRM188R71H104KA94L Murata(2) 0.1µF/6.3V Ceramic Capacitor, X7R, Size 0603 3 GRM188R70J105KA01D (2) 1µF/6.3V Ceramic Capacitor, X7R, Size 0603 1 (2) 0.1µF/100V Ceramic Capacitor, X7R, Size 0603 2 (2) 1nF/100V Cermiac Capacitor, X7R, Size 0603 1 (2) 10nF/50V Ceramic Capacitor, X7R, Size 0603 1 4.7µF/6.3V Ceramic Capacitor, X5R, Size 1206 1 100V Small Signal Schottky Diode, SOD123 1 5.6V Zener Diode, SOD323 1 C8 C9, C10 C11 C12 C14 D1 GRM188R72A104KA35D GRM188R72A102KA01D GRM188R71H103K GRM31CR60J475KA01L BAT46W D2 CMDZ5L6 L1 HCL1305-4R0-R Murata Murata Murata Murata (2) Murata (4) Diodes, Inc. (5) Central Semi (6) Cooper Bussmann 4.0µH Inductor, 10A RMS Current 1 (7) Q1 SIR432DP Vishay MOSFET, N-CH, Power SO-8 1 Q2 SIR804DP Vishay(7) MOSFET, N-CH, Power SO-8 1 Q3 FCX493 R1, R3 R2 CRCW060310K0FKEA CRCW08051R21FKEA R4 CRCW060380K6FKEA R5 CRCW060340K2FKEA R6 CRCW060320K0FKEA R7 CRCW060311K5FKEA R8 CRCW06038K06FKEA (4) ZETEX 100V NPN Transistor, SOT89 1 (7) 10kΩ Resistor, Size 0603, 1% 2 (7) 1.21Ω Resistor, Size 0805, 5% 1 (7) 80.6kΩ Resistor, Size 0603, 1% 1 (7) 40.2kΩ Resistor, Size 0603, 1% 1 (7) 20kΩ Resistor, Size 0603, 1% 1 (7) 11.5kΩ Resistor, Size 0603, 1% 1 (7) 8.06kΩ Resistor, Size 0603, 1% 1 (7) Vishay Dale Vishay Dale Vishay Dale Vishay Dale Vishay Dale Vishay Dale Vishay Dale R9 CRCW06034K75FKEA Vishay Dale 4.75kΩ Resistor, Size 0603, 1% 1 R10 CRCW06033K24FKEA Vishay Dale(7) 3.24kΩ Resistor, Size 0603, 1% 1 CRCW06031K91FKEA (7) 1.91kΩ Resistor, Size 0603, 1% 1 (7) 49.9Ω Resistor, Size 0603, 1% 1 (7) 0Ω Resistor, Size 0603, 5% 2 (7) 9.7kΩ Resistor, Size 0805, 5% 1 (8) 75V Synchronous Buck DC-DC Regulator 1 R11 R12 R13, R21 R14 U1 CRCW060349K24FKEA CRCW06030000FKEA CRCW08059K7FKEA MIC2176-2YMM Vishay Dale Vishay Dale Vishay Dale Vishay Dale Micrel. Inc. Notes: 1. EPCOS: www.epcos.com. 2. Murata: www.murata.com. 3. Sanyo: www.sanyo.com. 4. Diodes Inc.: www.diodes.com. 5. Central Semi: www.centralsemi.com. 6. Cooper Bussmann: www.cooperbussmann.com. 7. Vishay: www.vishay.com. 8. Micrel, Inc.: www.micrel.com. November 2010 3 M9999-111710 Micrel, Inc. MIC2176 5A Evaluation Board PCB Layout Recommendations MIC2176 Evaluation Board Top Layer November 2010 4 M9999-111710 Micrel, Inc. MIC2176 5A Evaluation Board PCB Layout Recommendations (Continued) MIC2176 Evaluation Board Mid-Layer 1 (Ground Plane) November 2010 5 M9999-111710 Micrel, Inc. MIC2176 5A Evaluation Board PCB Layout Recommendations (Continued) MIC2176 Evaluation Board Mid-Layer 2 November 2010 6 M9999-111710 Micrel, Inc. MIC2176 5A Evaluation Board PCB Layout Recommendations (Continued) MIC2176 Evaluation Board Bottom Layer November 2010 7 M9999-111710 Micrel, Inc. MIC2176 5A 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. November 2010 8 M9999-111710