STEVAL-ISQ009V1 Load share controller demonstration board based on the L6615 Data brief Features ■ Three paralleled DC-DC converter modules (in synchronous buck topology, managed by ST’s L6910) ■ Output currents shared through ST current sharing controller L6615 ■ Innovative use of a MOSFET as both the ORing element (replacing OR-ing diode) and sensing element (RDS(on)) ■ RoHS compliant Description The STEVAL-ISQ009V1 demonstration board is composed of three identical sections (daughterboards) and a motherboard. Each daughterboard is capable of performing DCDC conversion starting from +5 VDC and is designed to deliver 3.3 V / 5 A to the load. The input terminals of the motherboard are connected to a +5 VDC external source and the output terminals to the load. The board can accommodate up to three DC-DC converters. STEVAL-ISQ009V1 It is possible to verify that disabling one section (through the relevant switch on the motherboard) does not cause overvoltage on the output or overcurrent in other sections. In the same way, enabling one section (with the other two already running) does not cause negative output voltage drop or a short to ground, and current sharing is established. The motherboard contains the circuitry necessary to perform current sharing (utilizing the L6615) and to isolate a failed section from the load. It is designed to be adaptable to all power supplies (compatible with the L6615 absolute maximum ratings) having remote sense pins. By changing just a few components, it can be modified for new specifications. It is possible to build a system to supply a 10 A load at +3.3 V in a 2+1 redundant configuration. That is, whenever three sections are running, each of them supplies 3.33 A, a value lower than its nominal capability. If one of them is switched off, the system is able to supply the load, and each section carries 5 A. DC-DC conversion management is performed by the L6910. February 2010 Doc ID 17166 Rev 1 For further information contact your local STMicroelectronics sales office. 1/5 www.st.com 5 2/5 # Doc ID 17166 Rev 1 %!2%& 33 /#3%4 # #/-0 # 2 5 , 6&" 62%& 0'//$ 0'.$ ,'!4% 0(!3% 5'!4% # 2 2 # 1 2 $ 2 2 # , #n# # # $ # $ 2 2 2 33 0'.$ 3'.$ 3/54 /54 05-0 Figure 1. '.$ 6## "//4 # 1 # 2 $ 2 6## Schematic diagrams STEVAL-ISQ009V1 Schematic diagrams Single daughterboard circuit schematic ISQ009v1_schematic_1 !-V ). ). # # # 2 2 2 2 ,%$ 2 2 ,%$ 2 2 ,%$ $ $ $ 2 $ 2 $ 2 $ 2 5 2 5 2 5 2 Doc ID 17166 Rev 1 2 2 # 2 2 2 2 2 1 # 2 1 # 2 1 # 37 2 # 37 2 # 37 2 /54 6## /54 6## /54 6## 33 0'.$ 33 0'.$ 33 0'.$ 05-0 0'.$ 05-0 0'.$ 05-0 0'.$ 3'.$ 3/54 2 2 3'.$ 3/54 2 2 3'.$ 3/54 2 2 # # # # # # # # # $ $ $ 2 5 2 5 2 5 *0 # # *0 # # *0 # # 2 # 2 # 2 # 2 2 2 2 # 2 /54 /54 Figure 2. STEVAL-ISQ009V1 Schematic diagrams Motherboard circuit schematic !-V 3/5 Revision history 2 STEVAL-ISQ009V1 Revision history Table 1. 4/5 Document revision history Date Revision 22-Feb-2010 1 Changes Initial release. Doc ID 17166 Rev 1 STEVAL-ISQ009V1 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. 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