MAX2202XEVKIT# Analog Devices

Click here to ask about the production status of specific part numbers. Evaluates: MAX22025MAX22028/ MAX2202X Evaluation Kit MAX22025FMAX22028F Startup Procedure General Description The EV kit is fully assembled and tested. Follow the steps The MAX2202XEVKIT evaluation kit (EV kit) is a fully below to verify board operation. assembled and tested PCB that demonstrates the func- tionality of the MAX22028 isolated RS-485 transceiver 1) Set the DC power supply to 3.3V. with AutoDirection. The EV kit operates from a single 3.3V 2) Connect the DC power supply to the V test point DDA supply and features an on-board isolated power supply to (TP1). Connect the ground terminal to the GNDA test power the secondary side of the circuit. point (TP2). The MAX2202X EV kit ships with the MAX22028 installed. 3) Ensure that the jumpers are in their default positions The board can also be used to evaluate the MAX22025 (see Table 1). MAX22027 and the MAX22025FMAX22028F. 4) Turn on the power supply. Features 5) Connect the oscilloscope to the A and B test points Operates from a Single 3.3V Supply (TP7 and TP6, respectively). Terminal Block Connector for Easy RS-485 6) Set the signal/function generator to output a 100kHz Evaluation 0V-to-3.3V square wave. 3500V Isolation for 60s RMS 7) Connect the signal/function generator to the TXD test point (TP4). Fully Assembled and Tested 8) Verify that the A and B outputs switch as the signal Quick Start toggles. Required Equipment MAX2202X EV kit 3.3V, 500mA DC power supply Signal/function generator Oscilloscope Ordering Information appears at end of data sheet. 319-100440 Rev 2 5/20MAX2202X Evaluation Kit Evaluates: MAX22025MAX22028/ MAX22025FMAX22028F Evaluating the Isolated RS-485 Interface Detailed Description of Hardware The MAX2202X EV kit is a fully assembled and tested cir- The MAX2202X EV kit includes test points to access A cuit board for evaluating the MAX2202X isolated RS-485 (TP7) and B (TP6) for easy evaluation. To verify opera- transceiver with AutoDirection control. The EV kit is pow- tion in a RS-485 system, connect the transceiver to the ered from a single 3.3V power supply. network using the J1 terminal block and use the TXD and RXD test points (TP4 and TP5, respectively) to connect Powering the MAX2202X EV Kit the board to a logic controller. Alternatively, connect an The power on the EV kit is derived from a single 3.3V external controller to drive TXD using the J7 SMA connec- source. Connect an external supply to the V test point DDA tor and connect the controller to RXD using the J6 SMA (TP1) to supply the 3.3V to the logic-side (A-side) of the connector. circuit. The on-board MAX258 (U3) transformer driver and External Protection external transformer (T1) generate an isolated supply For harsh industrial environments, external protection for powering the isolated side (B-side) of the board. The might be necessary to protect the RS-485 transceiver dur- MAX8881 (U4) generates a regulated 5V for the B-side ing high voltage transient events. The MAX2202X EV kit of the board. includes pads for additional on-board protection that can To use an external supply on the isolated side of the be used when evaluating the device in a RS-485 network. board, remove the shunt on the J3 jumper and apply the Solder a diode to the U2 pad to add additional protection voltage to the V test point (TP8). DDB on the A and B lines when needed. Table 1. Jumper Table JUMPER SHUNT POSITION DESCRIPTION Open On-board termination is not connected between A and B. J2 Closed* On-board termination is connected between A and B. Open V is not powered by the on-board isolated power circuit. DDB J3 Closed* V is powered by the on-board isolated power circuit. DDB *Default position. Ordering Information PART TYPE MAX2202XEVKIT EV Kit Denotes RoHS-compliance. Maxim Integrated 2 www.maximintegrated.com