Evaluates: MAX20086MAX20089 MAX20087 Evaluation Kit General Description Quick Start The MAX20087 evaluation kit (EV kit) demonstrates the Required Equipment full capabilities of the series of power-protector ICs. The 3.3V power supply EV kit can operate as a stand-alone protector, or can be 12V power supply 2 connected to a controller through an I C interface for advanced control and diagnostics. The IC populated by 0.5A, 25 electronic resistive load default on the EV kit is the MAX20087, which has four Digital multimeter (DMM) output channels and a full suite of diagnostics active for compatibility with ASIL-grade applications. The EV kit is Procedure compatible with all other variants in the series, which can The EV kit is fully assembled and tested. Follow the steps be evaluated by replacing the existing IC (U1) with the below to verify board operation: desired one. 1) Connect the 3.3V supply across the VEXT and GND The EV kit allows for simultaneous and independent test loops. operation and evaluation of the four protected output power 2) Place jumper on the header next to VEXT test loop, channels. The EV kit has built-in interfaces to operate the connecting the center pin to the EXT pin. 2 part without needing an external I C controller, although 3) Activate the 3.3V supply. one can be connected to evaluate digital control and 4) Connect the 12V supply across the VIN and GND expanded diagnostics. test loops. Activate supply. 5) Use the DMM to verify that OUT1OUT4 are off (0V). Benefits and Features 6) Install a jumper on EN to pull pin to 3.3V supply. 400m (typ) Input-to-Output Channel Resistance 7) Use the DMM to verify that OUT1OUT4 are at 12V. 8) Connect the 0.5A load across GND and an output Automatic Shutdown and Retry on Output UV and channel. OC Conditions Reduces IC Power Dissipation 9) Use the DMM to verify that voltage on channel is Channels Continuously Shut Off During Overvoltage approximately 11.8V. Conditions to Protect the Rest of the System Capable of Basic Stand-Alone Operation or 2 Advanced Control and Diagnostics Through I C Interface Ordering Information appears at end of data sheet. Proven PCB Layout Fully Assembled and Tested 319-100175 Rev 0 4/18Evaluates: MAX20086MAX20089 MAX20087 Evaluation Kit EV Kit Interface Detailed Description of Hardware The MAX20086MAX20089 ICs are multichannel power Supply protectors designed for power-over-coax applications. The EV kit requires a main power supply as a source for The MAX20086/MAX20087 have four output channels, the four output channels and a small secondary supply and the MAX20088/MAX20089 have two output chan- for the ICs internal logic and control interface. The main nels. The MAX20086 and MAX20088 are standard ICs, supply can range from 3V to 15V, while the logic supply while the MAX20087 and MAX20089 have advanced should fall between 3V and 5V. Apply the main supply at functionality for ASIL-rated applications. By default, the the test points labelled VIN and GND, and the logic supply EV kit comes with the MAX20087 IC populated so that at the test points labelled VEXT and GND. the full feature set of the IC family can be evaluated with Control one kit. Stand-alone control can be exerted by simply placing or The IC takes in a single input power channel and feeds it removing the EN jumper (or applying a logic-high signal through to multiple output channels. Each output channel to the EN test point). Adding the jumper activates all the has independent diagnosis/protection from undervoltage, output channels, and removing it shuts them down. The overvoltage, overcurrent, and overtemperature condi- current limit is set by a single resistor on the ISET pin. tions. The input channel and logic supplies are also moni- The 600mA (max) current limit is set with a 100k resis- tored for undervoltage and overvoltage conditions. All tor the limit scales linearly down to 12k (72mA). The output channels have soft-start and soft-shutdown ramp recommended minimum current limit is 16.5k at 100mA. behavior to limit inrush current and avoid inductive ringing when used in power-over-coax applications. The INT pin is open-drain active-low, and asserts when- ever a fault occurs or when a triggered ADC conversion The IC can operate in stand-alone mode, with a single has completed (a pullup resistor for the INT pin is popu- enable input controlling all channels simultaneously and lated on the EV kit). By default, the pin shows real-time a single interrupt output communicating the presence of faults and deactivates when fault conditions are removed. 2 C interface any fault conditions. The ICs also feature an I The pin can be reconfigured to assert a fault until the for advanced control and diagnosis. Through the digital 2 diagnostic flags are read through I C. Likewise, different interface, users can exert individual channel enable/dis- fault types can be masked off the INT pin and register. By able control and determine specific fault types, and on default, all fault conditions assert the INT pin. which channel the fault was asserted. Additionally, each 2 IC contains an on-board ADC to make system measure- The I C address of the IC can be configured at the factory ments. Standard ICs can measure output channel cur- to be one of several addresses. Additionally, the ADDR rents, while ASIL-compliant ICs can also measure output pin of the IC sets one bit in the address. There is an channel voltages, input and logic supply voltages, and internal pulldown on the pin to default the address to 0x28 current-set resistor voltage. (default-factory address) populating the ADDR jumper to pull the pin high sets the address to 0x29. The EV kit has 2 pullup resistors on the I C lines. Note that the addresses 0x28 and 0x29 do not include the read/write bit that 2 the I C protocol requires. Refer to the MAX20087 IC data 2 sheet for a full description of the I C interface and avail- able control/diagnostic registers. Maxim Integrated 2 www.maximintegrated.com