MIC2194 Evaluation Board Micrel MIC2194 Evaluation Board 400kHz SO-8 Buck Control IC Introduction Quick-Start Guide Refer to Figure 1 for the following: 1. Connect the positive terminal from the power supply to VIN post (J1) on the MIC2194 evaluation board. 2. Connect the GND terminal of the input power supply to GND (J2). 3. Connect a digital voltmeter across VOUT (J3) and GND (J4) to measure output voltage. 4. Program the output voltage by selecting jumper JP1 to be in 3.3V, 2.5V, 1.8V, or 1.5V position. 5. Remove jumper JP2 to power up the board. 6. After turning the input supply on, the output voltage should read the programmed output voltage. Micrel’s MIC2194 is a high efficiency PWM non-synchronous buck control IC housed in the SO-8 package. Its 2.9V to 14V input voltage range allows it to efficiently step down voltages in 3.3V, 5V, and 12V systems as well as 1- or 2-cell Li-Ion battery powered applications. The MIC2194 solution saves valuable board space. The device is housed in the space-saving SO-8 package, whose low pin-count minimizes external components. Its 400kHz PWM operation allows a small inductor and small output capacitors to be used. The MIC2194 drives a high-side P-Channel MOSFET, eliminating the need for high-side bootstrap circuitry. This feature allows the MIC2194 to achieve maximum duty cycles of 100%, which can be useful in low headroom applications. A low output driver impedance of 2Ω allows the MIC2194 to drive large external MOSFETs to generate a wide range of output currents. The MIC2194 is available in an 8-pin SOIC package with a junction temperature range of –40°C to +125°C. MIC2194 Evaluation Board Input/Output Voltages and Load Current The MIC2194 evaluation board is designed to operate from VIN = 3.3V to 6V to produce an output voltage of 1.5V, 1.8V, 2.5V, or 3.3V at a load current of up to 5A. MICREL, INC. MIC2194BM JP1 VIN J1 VOUT J3 DVM VIN GND J2 GND J4 Figure 1. MIC2194 Evaluation Board Hook-up Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com October 2003 1 MIC2194 Evaluation Board MIC2194 Evaluation Board Micrel Evaluation Board Schematic J1 VIN = 3.3V to 6V VIN J2 RTN C5 1µF 10V R10 100kΩ 1 2 3 4 U1 MIC2194 R3 Open R1 30.1kΩ C10 Open VIN CSL 4 3 EN/UVLO OUTP 7 1 COMP FB 2 6 GND VDD 5 C2 100µF 20V GND Q2 Si4403DY 1 2 3 C6 22nF 25V GND 8 JP2 /SHDN C1 100µF 20V R2 0.015Ω 4 R12 15Ω Q1 Open L1 2.5µH 8 7 6 5 1 8 7 6 5 1 1 1 D1 B530 C7 330µF 6.3V 2 C9 300pF 25V J3 VOUT 2 2 C3 1µF 10V C8 330µF 6.3V C4 1µF 10V R6 10kΩ C12 open 2 J4 VOUT RTN GND GND 8 3 2.5V R4 6.03kΩ 3.3V 7 1.8V 6 4 1.5V R7 10kΩ 5 2 JP1 Header 4x2 R9 22.6kΩ 1 R8 48.7kΩ GND MIC2194 Evaluation Board 2 October 2003 MIC2194 Evaluation Board Micrel Evaluation Board Efficiency Figures 2 and 3 show the MIC2194 efficiency for input voltages of 5V and 3.3V for various output voltages. Output Transient Response MIC2194 Efficiency vs. Output Load Current 100 95 VOUT = 3.3V VOUT = 2.5V 20mV/div EFFICIENCY (%) 90 85 80 75 70 65 VOUT = 1.8V VIN = 5V VOUT = 1.5V ILOAD = 0.5A to 5A VOUT = 1.5V 60 55 50 0.1 VIN = 5V Si4403DY (1) 1 IOUT (A) 10 TIME (200µs/div) Figure 2. MIC2194 Evaluation Board Efficiency for VIN = 5V and VOUT = 3.3V, 2.5V, 1.8V and 1.5V MIC2194 Efficiency vs. Output Load Current 100 Output Transient Response VOUT = 2.5V 95 90 85 80 VOUT = 1.8V 20mV/div EFFICIENCY (%) Figure 5. MIC2194 Output Transient Response for VIN = 5V, VOUT = 1.5V, ILOAD = 0.5A to 5A 75 70 65 0.1 VIN = 3.3V Si4403DY (1) VOUT = 1.5V 1 IOUT (A) 10 VIN = 3.3V VOUT = 2.5V ILOAD = 0.5A to 5A Figure 3. MIC2194 Efficiency for VIN = 3.3V and VOUT = 2.5V, 1.8V and 1.5V Transient Response Figures 4 thru 9 show the transient response and output voltage ripple for the MIC2194 evaluation board for input voltage of 5V and 3.3V. TIME (200µs/div) Figure 6. MIC2194 Output Transient Response for VIN = 3.3V, VOUT = 2.5V, ILOAD = 0.5A to 5A Output Transient Response 50mV/div 20mV/div Output Transient Response VIN = 5V VOUT = 3.3V ILOAD = 0.5A to 5A VIN = 3.3V VOUT = 1.5V ILOAD = 0.5A to 5A TIME (200µs/div) TIME (200µs/div) Figure 4. MIC2194 Output Transient Response for VIN = 5V, VOUT = 3.3V, ILOAD = 0.5A to 5A October 2003 Figure 7. MIC2194 Output Transient Response for VIN = 3.3V, VOUT = 1.5V, ILOAD = 0.5A to 5A 3 MIC2194 Evaluation Board MIC2194 Evaluation Board Micrel 20mV/div Output Voltage Ripple 20mV/div Output Voltage Ripple VIN = 5V VOUT = 3.3V ILOAD = 5A VIN = 3.3V VOUT = 1.5V ILOAD = 5A TIME (4µs/div) TIME (4µs/div) Figure 8. MIC2194 Output Voltage Ripple for VIN = 5V, VOUT = 3.3V, ILOAD = 5A MIC2194 Evaluation Board Figure 9. MIC2194 Output Voltage Ripple for VIN = 3.3V, VOUT = 1.5V, ILOAD = 5A 4 October 2003 MIC2194 Evaluation Board Micrel Bill of Materials Item Part Number Manufacturer Description C1, C2 594D107X0020D2T Vishay/Sprague 100µF, 20V tantalum capacitor Qty. C3, C4, C5 GRM21BR71C105KA01B VJ0805S105KXJAT C2012 X5R 1C 105K Murata Vishay Vitramon TDK 1µF, 16V ceramic capacitor 1µF, 16V, X5R ceramic capacitor 2 3 OR OR C6 VJ0805Y223KXXAT Vishay Vitramon 22nF ceramic capacitor 1 C7, C8 594D337X06R3D2T Vishay/Sprague 330µF, 6.3V tantalum capacitor 2 C9 VJ0805Y301KXXAT Vishay Vitramon 300pF, 25V ceramic capacitor 1 Vishay Dale open, size 0805 0 C12, C10 D1 B530 SS53 SK54-L Diodes, Inc. Vishay MMC 5A, 30V Schottky diode J1-J5 2551-2-00-01-00-00-07-0 MilMax Turret Pins 5 JP1 S2012-04-ND Sullins 4x2 header 1 JP2 S1012-02-ND Sullins 2x1 header 1 JUMPER SNT-100-BL-G Samtec shorting jumper 2 L1 CDRH104R-2R5 Sumida 2.5µH, 6A inductor 1 Q1 Si4403DY open 0 Q2 Si4403DY MOSFET 1 R1 VJ08053012FRT1 Vishay Dale 30.1kΩ, size 0805,1/10W, 1% 1 R2 WSL-2010-R010-F Vishay Dale 0.010Ω, size 2010, 1% 1 R4 VJ08056031FRT1 Vishay Dale 6.03kΩ, size 0805, 1% 1 R6, R7 VJ08051002FRT1 Vishay Dale 10kΩ, size 0805, 1% 2 R8 VJ08054872FRT1 Vishay Dale 48.7kΩ, size 0805, 1% 1 R9 VJ08052262FRT1 Vishay Dale 22.6kΩ, size 0805, 1% 1 R10 VJ08051003FRT1 Vishay Dale 100kΩ, size 0805, 1% 1 R12 VJ080515R0FRT1 Vishay Dale 15Ω, size 0805, 1% 1 U1 MIC2194-BM Micrel Semiconductor Buck controller 1 Vishay/Siliconix Vendor Phone Numbers: 1 OR Shaded items not being used by evaluation board. 1. Vishay Corp. tel: 206-452-5664 2. Murata tel: 800-831-9172 3. TDK tel: 847-803-6100 4. Diodes, Inc. tel: 805-446-4800 5. MMC tel: 800-346-3371 6. Sumida tel: 408-321-9660 7. Micrel Semiconductor tel: 408-944-0800 October 2003 5 MIC2194 Evaluation Board MIC2194 Evaluation Board Micrel Printed Circuit Board Layouts Figure 10a. Top Silkscreen Figure 10c. Bottom Silkscreen Figure 10b. Top Layer MICREL, INC. TEL Figure 10d. Bottom Layer 1849 FORTUNE DRIVE SAN JOSE, CA 95131 + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB USA http://www.micrel.com The information furnished by Micrel in this datasheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. 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 at Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2003 Micrel, Incorporated. MIC2194 Evaluation Board 6 October 2003