XRPWRKIT-LWP-1

SP6669 600 mA 1.5 MHz PWM Synchronous Step Down Converter Design Tips Output Voltage Selection The output voltage is adjustable via the external resistor network R1 and R2 as per the following formula: Evaluation Board Configuration Input Voltage Output Voltage Max. Output Current Operating Frequency 2.5 V - 5.5 V 1.8 V 600 mA 1.5 MHz Inductor Reference 4.7 µH – WE-TPC 744 025 004 VOUT = VREF • (1+ R1 ) R2 Inductor Selection Inductor ripple current and saturation current ratings are two factors to be considered when selecting the inductor value. A low RDC inductor is preferred. The inductor value L can be calculated from the following equation: L = (VIN - VOUT) • ( VOUT VIN )•( up to 97 % efficiency 1 1 )•( ) ΔIL f DESIGN KIT Low Power – Point of Load Solutions Where L = Inductor value VIN = Input voltage VOUT = Output voltage f = Operating frequency ΔIL = Current ripple – usually set between 30% and 40% of output current desired Where VREF = Reference voltage at 0.6 V Inductor Value L – Resistor Values R1/R2 Selector VOUT/IOUT 100 mA VIN = 3.3 V 300 mA 600 mA 3.3 V 2.8 V 2.5 V 1.8 V 1.2 V 0.8 V 10 μH 744 032 910 0 15 μH 744 025 150 15 μH 744 025 150 15 μH 744 025 150 15 μH 744 025 150 Best suitable inductor 3.3 μH 744 025 003 4.7 μH 744 032 900 4 4.7 μH 744 032 900 4 4.7 μH 744 032 900 4 4.7 μH 744 032 900 4 1.5 μH 2.2 μH 744 032 900 2 3.3 μH 744 025 003 3.3 μH 744 025 003 2.2 μH 744 032 9002 Lowest profile inductor 100 mA 22 μH 744 025 220 22 μH 744 025 220 22 μH 744 025 220 22 μH 744 025 220 18 μH 744 032 180 15 μH 744 032 001 5 VIN = 5.0 V 300 mA 6.8 μH 744 025 006 6.8 μH 744 025 006 6.8 μH 744 025 006 6.8 μH 744 025 006 6.8 μH 744 025 006 4.7 μH 744 025 004 600 mA 4.7 μH 744 025 004 4.7 μH 744 025 004 4.7 μH 744 025 004 4.7 μH 744 025 004 3.3 μH 744 025 003 2.2 μH 744 025 002 R1 The feedback resistors must be chosen such that power dissipation of the network is minimal. R1 and R2 are typically allowed within a given range; adhere to the recommended values in the tables. R2 453 kΩ 100 kΩ 365 kΩ 100 kΩ 316 kΩ 100 kΩ The inductor value for the evaluation boards is set for an output current ripple of approximately 30% to 40% of the maximum output current desired. An output current ripple level of 30% to 40% is acceptable in most designs and may provide extra flexibility in selecting the appropriate inductor value. Note All product documentations, including datasheets, evaluation board manuals and bill of material can be found on www.exar.com/wurth_electronics www.we-online.com/exar 200 kΩ 100 kΩ 100 kΩ 100 kΩ 33 kΩ 100 kΩ Evaluation board configuration 3 www.we-online.com 600 mA to 1.5 A, Low Input Voltage Single and Dual Channel Converter 01/12 Order Code IC-744 721 Version 1.0 Exar Device Max. Output Current Input Voltage Range Output Voltage Range Operating Frequency Max Efficiency Package SP6669 XRP6658 XRP6668 XRP6657 0.6 A 1A 1A / 1A 1.5 A 2.5 V - 5.5 V 2.5 V - 5.5 V 2.5 V - 5.5 V 2.5 V - 5.5 V 0.6 V - VIN 0.6 V - VIN 0.6 V - VIN 0.6 V - VIN 1.5 MHz 1.5 MHz 1.5 MHz 1.5 MHz 95 % 97 % 97 % / 97 % 95 % SOT23-5 SOT23-5 SOIC8 DFN6 Würth Elektronik Inductor Value 4.7 µH 2.2 µH 2.2 µH / 2.2 µH 1.8 µH Reference 744 025 004 744 043 002 2 744 043 002 2 744 773 018 XRP6658 More information on www.we-online.com/exar 1 A 1.5 MHz Synchronous Step Down Converter Evaluation Board Configuration XRP6668 XRP6657 1 A/1 A Dual Channel 1.5 MHz Synchronous Step Down Converter 1.5 A 1.3 MHz Synchronous Step Down Converter Evaluation Board Configuration Evaluation Board Configuration Input Voltage Output Voltage Max. Output Current Operating Frequency 2.5 V - 5.5 V 3.3 V 1A 1.5 MHz Input Voltage Output Voltage Max. Output Current Operating Frequency 2.5 V - 5.5 V 3.3 V / 1.8 V 1 A/1 A 1.5 MHz Input Voltage Output Voltage Max. Output Current Operating Frequency 2.5 V - 5.5 V 1.8 V 1.5 A 1.3 MHz Inductor Reference 2.2 µH – WE-TPC 744 043 002 2 Inductor Reference 2.2 µH – WE-TPC 744 043 002 2 Inductor Reference 1.8 µH – WE-PD2 744 773 018 Inductor Value L – Resistor Values R1/R2 Selector VOUT/IOUT 100 mA VIN = 3.3 V 500 mA 1000 mA 3.3 V 2.8 V 2.5 V 1.8 V 1.2 V 0.8 V 10 μH 744 089 431 00 15 μH 744 089 431 50 15 μH 744 089 431 50 15 μH 744 089 431 50 15 μH 744 089 431 50 Best suitable inductor 1.8 μH 744 043 001 8 2.2 μH 744 043 002 2 3.3 μH 744 373 240 33 3.3 μH 744 373 240 33 2.2 μH 744 043 002 2 1.0 μH 744 089 430 10 1.2 μH 744 373 240 12 1.5 μH 744 373 240 15 1.5 μH 744 373 240 15 1.2 μH 744 373 240 12 Lowest profile inductor 100 mA 22 μH 744 089 432 20 22 μH 744 089 432 20 22 μH 744 089 432 20 22 μH 744 089 432 20 18 μH 744 043 180 15 μH 744 089 431 50 Inductor Value L – Resistor Values R1/R2 Selector VIN = 5.0 V 500 mA 4.7 μH 744 373 240 47 4.7 μH 744 373 240 47 4.7 μH 744 373 240 47 6.8 μH 744 089 430 68 3.3 μH 744 373 240 33 3.3 μH 744 373 240 33 Evaluation board configuration 1000 mA 2.2 μH 744 043 002 2 2.2 μH 744 373 240 22 2.2 μH 744 373 240 22 2.2 μH 744 043 002 2 1.8 μH 744 043 001 8 1.5 μH 744 373 240 15 R1 R2 VOUT/IOUT 453 kΩ 100 kΩ 3.3 V 365 kΩ 100 kΩ 2.8 V 316 kΩ 100 kΩ 2.5 V 200 kΩ 100 kΩ 1.8 V 100 kΩ 100 kΩ 1.2 V 33 kΩ 100 kΩ 0.8 V 100 mA 10 μH 744 089 431 00 15 μH 744 089 431 50 15 μH 744 089 431 50 15 μH 744 089 431 50 15 μH 744 089 431 50 Best suitable inductor VIN = 3.3 V 500 mA 1.8 μH 744 043 001 8 2.2 μH 744 043 002 2 3.3 μH 744 373 240 33 3.3 μH 744 373 240 33 2.2 μH 744 043 002 2 1000 mA 1.0 μH 744 089 430 10 1.2 μH 744 373 240 12 1.5 μH 744 373 240 15 1.5 μH 744 373 240 15 1.2 μH 744 373 240 12 Lowest profile inductor 100 mA 22 μH 744 089 432 20 22 μH 744 089 432 20 22 μH 744 089 432 20 22 μH 744 089 432 20 18 μH 744 043 180 15 μH 744 089 431 50 Inductor Value L – Resistor Values R1/R2 Selector VIN = 5.0 V 500 mA 4.7 μH 744 373 240 47 4.7 μH 744 373 240 47 4.7 μH 744 373 240 47 6.8 μH 744 089 430 68 3.3 μH 744 373 240 33 3.3 μH 744 373 240 33 1000 mA 2.2 μH 744 043 002 2 2.2 μH 744 373 240 22 2.2 μH 744 373 240 22 2.2 μH 744 043 002 2 1.8 μH 744 043 001 8 1.5 μH 744 373 240 15 R1 R2 VOUT/IOUT 453 kΩ 100 kΩ 3.3 V 365 kΩ 100 kΩ 2.8 V 316 kΩ 100 kΩ 2.5 V 200 kΩ 100 kΩ 1.8 V 100 kΩ 100 kΩ 1.2 V 33 kΩ 100 kΩ 0.8 V Evaluation board configuration 100 mA 10 μH 744 042 100 15 μH 744 042 150 18 μH 744 042 180 18 μH 744 042 180 15 μH 744 042 150 Best suitable inductor VIN = 3.3 V 750 mA 1.5 μH 744 373 240 15 1.8 μH 744 773 018 2.2 μH 744 773 022 2.2 μH 744 773 022 1.8 μH 744 773 018 1500 mA 1.0 μH 744 373 240 10 1.0 μH 744 373 240 10 1.5 μH 744 373 240 15 1.0 μH 744 373 240 10 1.0 μH 744 373 240 10 Lowest profile inductor 100 mA 33 μH 744 042 330 33 μH 744 042 330 33 μH 744 042 330 33 μH 744 042 330 22 μH 744 373 242 20 15 μH 744 042 150 VIN = 5.0 V 750 mA 1500 mA 3.3 μH 1.8 μH 744 373 240 33 744 042 018 3.3 μH 1.8 μH 744 373 240 33 744 042 018 3.3 μH 1.8 μH 744 373 240 33 744 773 018 3.3 μH 1.8 μH 744 373 240 33 744 773 018 3.3 μH 1.5 μH 744 373 240 33 744 373 240 15 2.2 μH 1.0 μH 744 773 022 744 373 240 10 R1 R2 453 kΩ 100 kΩ 365 kΩ 100 kΩ 316 kΩ 100 kΩ 200 kΩ 100 kΩ 100 kΩ 100 kΩ 33 kΩ 100 kΩ Evaluation board configuration Note: The above table values apply to each channel of the XRP6668. 2 www.we-online.com 4 5