Evaluates: MAX20046 MAX20046 Evaluation Kit General Description Quick Start The MAX20046 evaluation kit (EV kit) demonstrates Required Equipment the MAX20046 automotive Hi-Speed USB 2.0 protector MAX20046 EV kit switch IC, featuring overvoltage protection (OVP), electro- 5V, 2A DC power supply (Supply A) static discharge (ESD) protection, and undervoltage lock- out (UVLO)/overcurrent protection (OCP) for automotive 18V, 2A DC power supply (Supply B) USB applications. Logic function generator The device protects the USB BUS, D+, and D- data lines Oscilloscope from overvoltage conditions, such as a short-to-battery and ESD events. UVLO protects the BUS against low- Procedure voltage conditions such as a short-to-ground. The BUS The EV kit is fully assembled and tested. Follow the OCP uses a blanking period allowing momentary BUS steps below to verify board operation. Caution: Do not shorts to be ignored. All faults can be monitored using the turn on the power supplies until all connections are FAULT output signal. completed. The device can pass high-speed USB differential (D+ 1) Verify that shunts are installed as follows: and D-) signals up to 480Mbps and has a low 500m JU1: Pins 1-2 (MAX20046 BUS switch disabled) R (max) for the BUS and a 3.3 R (typ) for the D+ ON ON JU2: Pins 1-2 (IN connected to on-board 3.3V and D- lines. The EV kit is powered by the USB BUS. An reference) on-board MAX15007A automotive regulator provides the 2) Set the Supply A output to 5V, the Supply B output to IN reference voltage. If a 60mA/120mA current threshold 18V, and disable both outputs. is desired, the MAX20046GTC/V+ can be ordered and interchanged with U1. 3) Set the logic function generator as follows: 3V , 1.5V P-P DC offset square wave, 500kHz, and disable the output. Benefits and Features 4) Connect the Supply A positive output to the red BUS Protects USB BUS, D+, and D- Signals from test point on the EV kit and connect the supply ground Overvoltages Up to 18V and ESD Events to the nearby black GND test point. 5) Connect the Supply B ground to the GND test point USB BUS Undervoltage Lockout close to the HVBUS test point on the EV kit. Connect 23mA/45mA (typ) USB BUS Overcurrent-Protection a voltage probe test lead to the Supply B positive out- Threshold put for later use. 1ms Overcurrent Blanking Time 6) Using a Type A USB receptacle inserted into J3, Passes 480Mbps USB Data Signals connect the logic function generator to D+ and GND. Low On-Resistance 7) Enable both power-supply outputs. BUS: 500m (max) 8) Enable the function generator output. D+ and D-: 3.3 (typ) 9) Install a shunt on jumper JU1, pins 2-3 (MAX20046 FAULT Output Signal BUS switch enabled). USB Powered 10) Use the oscilloscope to probe the HVBUS and HVD+ test points. Fully Assembled and Tested 11) Verify that HVBUS is 5V and that the waveform on HVD+ Evaluates the MAX20046 IC in a 12-Pin TQFN is a 500kHz square wave and is approximately 3V . Package P-P 12) Momentarily touch the HVBUS test point on the EV kit with the voltage probe from the Supply B positive Ordering Information appears at end of data sheet. output. The FAULT signal asserts a logic-low while the fault is present. 19-8763 Rev 0 1/17Evaluates: MAX20046 MAX20046 Evaluation Kit that turns off the switch between HVBUS and BUS during Detailed Description of Hardware an overvoltage on HVBUS however, energy stored in the The MAX20046 EV kit demonstrates the MAX20046 auto- wiring inductance can cause the HVBUS node voltage motive Hi-Speed USB 2.0 protector switch IC, featuring to quickly increase. The RC snubber network limits the OVP, ESD protection, UVLO protection, and OCP for auto- positive voltage spike caused by wiring inductance. motive USB applications. Jumper Settings The IC protects the USB BUS, D+, and D- data lines from overvoltage conditions, such as a short-to-battery up to BUS Switch Enable (JU1) 18V and ESD events up to 25kV (air) and 8kV (contact). Jumper JU1 on the EV kit enables the devices BUS The OVP feature protects the D+ and D- lines against switch. Test points EN and GND are provided to control high-voltage conditions such as a short-to-BUS. The U1s enable signal with an external controller. Refer to the UVLO feature protects the BUS line against low-voltage EN Input section in the Electrical Characteristics table in conditions such as a short-to-ground. The BUS OCP the MAX20046 IC data sheet for proper EN logic levels threshold is fixed at 23mA/45mA (typ). A 1ms blanking when using an external controller. See Table 1 for proper period allows momentary BUS shorts to be ignored, such JU1 jumper settings. as those created by hot-swapping a capacitive load. All faults can be monitored using the FAULT PCB pad, pulled IN Reference Voltage Selection (JU2) up to IN through resistor R1. Jumper JU2 on the EV kit selects the reference voltage for the devices IN pin. IN can either be supplied by the The device can pass high-speed USB differential (D+ and USB BUS through the on-board automotive 3.3V regulator D-) signals up to 480Mbps, and has a low 500m R ON (U2, MAX15007A), or by a user-supplied reference volt- (max) for BUS and a 3.3 R (typ) for the D+ and D- ON age. Test points VIN and GND are provided to supply the data lines. The EV kit is powered by the USB BUS. The device with an external 3V to 3.6V reference voltage. See 3.3V automotive regulator (U2, MAX15007A) provides an Table 2 for proper JU2 jumper settings. on- board IN reference voltage. A user can provide a 3V to 3.6V IN reference voltage across the VIN and GND PCB ISET OCP Threshold Selection (JU3) pads. The MAX20046 (U1) ICs automotive operating Jumper JU3 on the EV kit selects the current threshold temperature range is from -40C to +105C. for OCP (overcurrent protection). With pins 1-2 shorted, Long USB wire lengths contribute to increased wiring the current threshold is 45mA. With pins 2-3 shorted, the inductance, resulting in slow di/dt and dV/dt during a current threshold is 23mA. See Table 3 for proper JU3 short to 18V event. The device includes internal circuitry jumper settings. Table 1. MAX20046 Enable (JU1) SHUNT POSITION EN PIN BUS SWITCH 1-2 Connected to IN Disabled 2-3 Connected to GND Enabled Not installed Connected to EN PCB pad EN externally controlled Table 2. MAX20046 IN Reference Voltage Selection (JU2) SHUNT POSITION IN PIN 1-2 Connected to on-board LDO 2-3 Connected to IN test point Not installed Unconnected Maxim Integrated 2 www.maximintegrated.com