DC1503A-A Analog Devices

DEMO MANUAL DC1503A LTM2881: Isolated 20Mbps RS485/RS422 Module Transceiver with Power DESCRIPTION supply on V . The part generates the output voltage V Demonstration circuit DC1503A is an Isolated RS485/ L CC2 and communicates all necessary signaling across the RS422 Module transceiver + power featuring the isolation barrier using isolation Module technology. LTM 2881. The demo circuit is a 2500V galvanically RMS isolated RS485/RS422 transceiver interface. All compo- Design les for this circuit board are available at nents are integrated into the Module transceiver. The DEMO MANUAL DC1503A QUICK START PROCEDURE Demonstration circuit DC1503A is easy to set up to evalu- 2. With power off, connect the input power supply to V CC ate the performance of the LTM2881. Refer to Figure 2 and GND. for proper measurement equipment setup and follow the 3. Turn on the power at the input. procedure below: Note: Make sure that the input voltage does not exceed Use a short ground lead on the oscilloscope probe when 6V. measuring input or output voltage ripple or high speed 4. Check for the proper output voltages. V = 5V, LED signals. CC2 D1 is On, LED D2 is On. 1. Place jumpers in the following positions: (all are default 5. Once the proper output voltages are established, connect except JP1, JP2, JP6 and JP8) a function generator to terminal DI and set to square JP1 ON wave with a low of 0V, high = V , termination is Hi-Z. CC JP2 V (Note: Logic signals referenced to V ) Set Frequency to 10MHz (20Mbps). Enable output of CC CC function generator. JP3 ON 6. Connect oscilloscope to terminal RO and observe wave- JP4 OUT form at 10MHz. This demonstration shows data that JP5 ON transmits from DI, loops back through the half-duplex con guration, and out of RO. JP6 EXT JP7 ON JP8 ON JP9 ON JP10 FAST JP11 HI SW1 HALF DUPLEX RO 1V/DIV DC1503 F01 50ns/DIV Figure 1. RO Output dc1503fa 2