The revision history describes the changes that were implemented in the document. The changes are listed by revision, starting with the most current publication. Revision 1.0 This document was published in November 2017. It was the first publication of this document. Microsemi Proprietary and Confidential. LX7180A User Guide Revision 1.0...
0.6 V to 1.195 V through a high speed (up to 3.4 MHz), bi- directional I C bus. The LX7180A operates from 3 V to 5.5 V rails and outputs 0.6 V to 100% of the input voltage. Cycle-by-cycle current limiting protects against over-current conditions. Hiccup mode provides protection for heavy over-load or short-circuit faults.
Figure 2 • Power Supply and Load Connection with I²C Implemented The following illustration shows how to connect the board to the power supply without I C. Figure 3 • Power Supply and Load Connection Without I²C Implemented Microsemi Proprietary and Confidential. LX7180A User Guide Revision 1.0...
R1 and R2. is determined by the chip. For example, to set the LX7180A to a VOUT= 1.8 V, given V = 0.6 V, first pick the lower resistor R2= 120K, calculate the upper resistor R1= 240K.
LX7180A 4 Amp Step-Down Converter Evaluation Board PCB Layout of Evaluation Board The LX7180A evaluation board is a four-layer board. The recommended distance between ground layer and the top layer is 6 mil. The following illustrations depict each of the board's four layers.
LX7180A 4 Amp Step-Down Converter Evaluation Board Efficiency Plot The following graph shows the efficiency of the LX7180A at a voltage output of 1 V. Figure 8 • Efficiency Plot Microsemi Proprietary and Confidential. LX7180A User Guide Revision 1.0...
LX7180A 4 Amp Step-Down Converter Evaluation Board Dynamic Load Response Scope Shots The following illustrations show the dynamic load response for the evaluation board. Figure 9 • Step Response Note: CH2: VOUT, CH4: I LOAD Microsemi Proprietary and Confidential. LX7180A User Guide Revision 1.0...
LX7180A 4 Amp Step-Down Converter Evaluation Board Start-up and Short Condition Scope Shots The following illustrations show the scope shots for the LX7180A. Figure 12 • Start-up With ENABLE Toggled Note: CH1: PG, CH2: EN, CH3: V , CH4: inductor current.
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LX7180A 4 Amp Step-Down Converter Evaluation Board Figure 13 • Soft-Start VIN Tied to ENABLE Note: CH1: PG, CH3: V , CH4: inductor current. Microsemi Proprietary and Confidential. LX7180A User Guide Revision 1.0...
"x" stands for the 2 LSB bits of the binary I C slave address (0 to 3), and "y" is the set output voltage (0 is 0.6 V, 1 is 0.9 V, 2 is 0.95 V, and 3 is 0.97 V). Microsemi Proprietary and Confidential. LX7180A User Guide Revision 1.0...
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