MP1567DQ

EV0060 (MP1567) 1.2A, 6V, 800KHz Synchronous Rectified Step-Down Converter The Future of Analog IC Technology EVALUATION BOARD GENERAL DESCRIPTION The EV0060 is an evaluation board for the MP1567, a 1.2A, 800KHz DC to DC converter designed for low voltage applications requiring high efficiency. Capable of providing output voltages as low as 0.9V from a 3.3V supply voltage, the MP1567 eliminates the need for a 5V rail, providing over 90% efficiency via synchronous rectification and eliminating heat issues in confined spaces. Soft-start operation protects internal circuitry from hard turn on issues. Switching at 800KHz reduces the size of external components and thereby reduces board space. The MP1567 includes cycle-by-cycle current limiting and under voltage lockout. Internal power switches combined with the tiny 10-pin QFN package provide a solution requiring a minimum of space. FEATURES • • • • • • • • • • • • • • • • 1.2A Output Current Synchronous Rectified Internal 180mΩ and 220mΩ Power Switches VIN Range of 2.6V to 6V Over 90% Efficiency Zero Current Shutdown Mode Under Voltage Lockout Protection Soft-Start Operation Thermal Shutdown Internal Current Limit (Source & Sink) Tiny 10-Pin QFN Package SOHO Routers, PCMCIA Cards, Mini PCI Handheld Computers, PDAs Cell Phones Digital Video Cameras Small LCD Displays APPLICATIONS ELECTRICAL SPECIFICATIONS Parameter Input Voltage Output Voltage Output Current Symbol VIN VOUT IOUT Value 2.6 to 6 1.8 1.2 Units V V A “MPS” and “The Future of Analog IC Technology”, are Registered Trademarks of Monolithic Power Systems, Inc. EV0060 EVALUATION BOARD Efficiency vs Load Current 100 90 80 EFFICIENCY (%) VIN=3.3V 70 60 50 40 30 20 10 VOUT=1.8V 10 100 LOAD CURRENT (mA) 1000 0 VIN=5V VIN=4V Dimensions (2.5”X x 2.0”Y x 0.4”Z) Board Number EV0060 EV0060 Rev. 1.2 4/22/2005 MPS IC Number MP1567DQ MP1567_EC01 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 1 EV0060 – 1.2A, 6V, 800KHz SYNCHRONOUS RECTIFIED STEP-DOWN CONVERTER EVALUATION BOARD EVALUATION BOARD SCHEMATIC IN GND C1 NS C11 10nF C3 10nF 1 2 3 MP1567 BS IN SW PGND SGND EN BP COMP FB SS 10 9 8 7 6 EN C7 10nF C4 NS C10 10nF C5 4.7nF C6 NS OUT GND C9 NS D1 MBR0520L 4 5 U1 EV0060_S01 EV0060 BILL OF MATERIALS Qty 4 2 4 1 1 1 1 1 2 1 Ref C1, C4, C6, C9 C2, C8 C3, C7, C10, C11 C5 D1 L1 R1 R2 R3, R4 U1 Value NS 10µF 10nF 4.7nF 6.2µH 0Ω 4.99kΩ 10kΩ Description Not Stuffed Capacitor Capacitor Capacitor Diode Inductor Resistor Resistor, 1% Step-Down Converter QFN10 MPS MP1567DK MBR0520L Sumida CDRH5D18 Package Manufacturer P/N Distributor P/N EV0060 Rev. 1.2 4/22/2005 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 2 EV0060 – 1.2A, 6V, 800KHz SYNCHRONOUS RECTIFIED STEP-DOWN CONVERTER EVALUATION BOARD PRINTED CIRCUIT BOARD LAYOUT Figure 1—Top Silk Layer Figure 2—Top Layer Figure 3—Bottom Layer EV0060 Rev. 1.2 4/22/2005 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 3 EV0060 – 1.2A, 6V, 800KHz SYNCHRONOUS RECTIFIED STEP-DOWN CONVERTER EVALUATION BOARD TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.3V, VOUT = 1.8V, TA = +25°C, unless otherwise noted. 2.5 2.0 1.5 1.0 0.5 0 ILOAD 0.5A/div. Current Limit vs. Duty Cycle VOUT 50mV/div. Load Transient 0.1A to 1A Load Step CURRENT LIMIT (A) VSS 1V/div. VOUT 1V/div. IIN 0.5A/div. 0 20 40 60 DUTY CYCLE (%) 80 MP1567-TPC01 MP1567-TPC02 2ms/div. MP1567-TPC03 Output Short Circuit IOUT = 1A Steady State VOUT 1V/div. VSW 2V/div. VSS 1mV/div. IINDUCTOR 1A/div. IINDUCTOR 1A/div. 2ms/div. MP1567-TPC04 MP1567-TPC05 EV0060 Rev. 1.2 4/22/2005 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 4 EV0060 – 1.2A, 6V, 800KHz SYNCHRONOUS RECTIFIED STEP-DOWN CONVERTER EVALUATION BOARD QUICK START GUIDE The output voltage of this board is set to 1.8V. The board layout accommodates most commonly used inductors and output capacitors. 1. Attach the positive and negative ends of the load to the OUT and GND pins respectively. 2. Attach an input voltage 2.6V ≤ VIN ≤ 6V and the input ground to the IN and GND pins, respectively. 3. To enable the MP1567 apply a voltage, 2V ≤ VEN ≤ 6V, to the EN pin. To disable the MP1567 connect the EN pin to ground. 4. The output voltage VOUT can be changed by varying R3. Calculate the new value using the formula: ⎛V ⎞ R3 = R4 × ⎜ OUT − 1⎟ ⎜V ⎟ ⎝ FB ⎠ Where VFB = 0.9V and R4 = 10kΩ. For example, for VOUT = 2.5V: ⎛V ⎞ ⎛ 2 .5 V ⎞ R3 = R4 × ⎜ OUT − 1⎟ = 10kΩ × ⎜ − 1⎟ = 17.78kΩ ⎜V ⎟ ⎝ 0. 9 V ⎠ ⎝ FB ⎠ Therefore use a standard 1% value 17.8kΩ resistor. Note: See Maximum Duty Cycle limits to determine allowable output voltages. NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications. Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. EV0060 Rev. 1.2 4/22/2005 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 5