Click here for production status of specific part numbers. Evaluates: MAX33040E MAX33040E Shield Evaluation Kit General Description Quick Start The MAX33040E shield evaluation kit (EV kit) is a fully Required Equipment assembled and tested printed circuit board (PCB) that demonstrates the functionality of the MAX33040E con- MAX33040E shield EV kit troller area network (CAN) transceiver with 40V fault 3.3V, 500mA DC power supply protection extended 25V common-mode input range and Signal/function generator that can generate 2.5MHz 40kV ESD human body model (HBM). The EV kit fea- tures a digital isolator, which is used as a level translator square wave signal between the CAN transceiver and the controller interface. Oscilloscope Features Easy Evaluation of the MAX33040E I/O Interface Compatibility from 1.71V to 5.5V Ordering Information appears at end of data sheet. Proven PCB Layout Mbed /Arduino Platform + Fully Assembled and Tested EV Kit Photo with Jumper and Test Point Positions Arduino is a registered trademark of Arduino, LLC. Mbed is a trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere. 319-100632 Rev 0 11/20MAX33040E Shield Evaluation Kit Evaluates: MAX33040E can also come from the Arduino/Mbed boards 3.3V rail. Procedure Place the shunt on 2-3 position of JU11 to connect VDD The following procedure can be used to test the to the VDD EXT pin. Place the shunt of JU11 on 1-2 MAX33040E shield EV kit as a standalone evaluation position to connect VDD of U1 to the Arduino/Mbed 3.3V board. supply rail. In this scenario, IOREF is directly taken from 1) Place the MAX33040E shield EV kit on a noncon- the Arduino/Mbed header. ductive surface to ensure that nothing on the PCB On-Board Termination gets shorted to the workspace. A properly terminated CAN bus is terminated at each end 2) Set all the jumpers to their default positions as with the characteristic impedance of the cable. For CAT5 shown in Table 1. or CAT6 cables, this is typically 120 on each end for a 3) With +3.3V power supply disabled, connect the posi- 60 load on the CAN driver. The MAX33040E shield EV tive terminal to the VDD EXT test point and IOREF kit features a selectable 60 load and a 6060 split (pin 7 of P4). Connect the negative terminal to the termination circuit between the CANH and CANL driver GND test point. outputs. The 6060 split termination has a footprint for a capacitor to reduce high-frequency noise and common- 4) Connect the positive terminal of the function genera- mode drift. If the board is evaluated in a system and is tor to the D1 (pin 2 of P2) and negative terminal to connected at the end of the cable, then select the 120 any GND test point on the shield. D1 is connected (6060 split) termination. The termination resistors to MAX33040Es TXD pin through the digital isolator on the MAX33040E shield EV kit changes to 60 with a (U2). 100pF load (using JU7 and JU8), to simulate a complete system load during evaluation. 5) Set function generator to the output a 2.5MHz square wave between 0V and 3.3V, and then enable TXD and RXD Configuration function generator output. Digital channels for TXD and RXD are selected through 6) Turn on the +3.3V DC power supply. JU1. It consists of three columns and 16 rows. The col- 7) Connect an oscilloscope probe on D0 (pin 1 of P2) umns labeled TXD and RXD are connected to MAX33040E and verify the D0 output signal (RXD) matches the through the digital isolator (MAX14931FASE+ (U2)). The middle column is the digital I/O pins, D0 to D15, from D1 input signal (TXD). the Arduino/Mbed header. This provides flexibility for the user to select different resources on the microcontroller to Detailed Description of Hardware transmit and receive signals to and from the CAN trans- The MAX33040E shield EV kit is a fully assembled and ceiver. Table 2 shows the list of JU1 jumper options. tested circuit board for evaluating the MAX33040E fault- protected high-speed CAN transceiver (U1) with 40V of DB9 Connector fault protection. The EV kit is designed to evaluate the The MAX33040E shield EV kit has a DB9 connector to MAX33040E alone or in a CAN system. The MAX33040E CANH and CANL (pins 7 and 2, respectively). shield EV kit enables Mbed or Arduino platform to com- municate on a CAN bus, or it can be used as a standalone The MAX33040E shield EV kit allows multiple points of evaluation board. The MAX14931 digital isolator is used connection to the MAX33040E transceiver. The EV kit as a level translator with a 1.71V to 5.5V supply range. board can be placed on a Arduino/Mbed- compatible Disconnect jumper JU15 to apply the transmitter input board to connect all the digital pins (TXD, RXD, STBY, signal directly on the TXD test point. Likewise, discon- SHDN) through the P1 and P2 headers. These signals nect jumper JU16 to measure the receiver output signal can also be connected directly at their respective test directly on the RXD test point. If external protection is points on the board, bypassing the digital isolator (U2). desired beyond the devices built-in protection, the EV kit The CANH, CANL signals are connected to a terminal also features footprints for TVS diodes (D1 and D2) that block (JU13) to easily connect to a twisted pair cable. can be connected to the CANH and CANL lines using JU5 These signals are also routed to a DB9 connector (CANH and JU6, respectively. and CANL on pins 7 and 2, respectively). Alternately, the CANH and CANL test points can be used.w Powering the Board SD Card The MAX33040E shield EV kit requires two power sup- plies: one 3V3.6V supply for the MAX33040E (U1) The MAX33040E shield EV kit has a microSD card socket transceiver applied at the VDD EXT test point, and one for easy use in OBD applications. The microSD card is 1.71V5.5V supply for the microcontroller domain applied connected to D10D13 to interface with the Arduino/Mbed at the IOREF test point. When the EV kit board is used board through the SPI interface. with an Arduino/Mbed board, the power supply for U1 Maxim Integrated 2 www.maximintegrated.com