LTC2872 RS232/RS485 Dual Multiprotocol Transceiver with Integrated Termination Fea T Descrip T n Four RS232 and Two RS485 Transceivers The LTC 2872 is a robust pin-configurable transceiver n 3V to 5.5V Supply Voltage that supports RS232, RS485, and RS422 standards while n 20Mbps RS485 and 500kbps RS232 operating on a single 3V to 5.5V supply. The LTC2872 can n Automatic Selection of Integrated RS485 (120) be configured as four RS232 single-ended transceivers and RS232 (5k) Termination Resistors or two RS485 differential transceivers, or combinations n Half-/Full-Duplex RS485 Switching of both, on shared I/O lines. n Logic Loopback Mode Pin-controlled integrated termination resistors allow n High ESD: 16kV on Line I/O for easy interface reconfiguration, eliminating external n 1.7V to 5.5V Logic Interface resistors and control relays. Half-duplex switches allow n Supports Up to 256 RS485 Nodes four-wire and two-wire RS485 configurations. Loopback n RS485 Receiver Full Failsafe Eliminates UART Lockup mode steers the driver inputs to the receiver outputs for n Available in 38-Pin 5mm 7mm QFN Package diagnostic self-test. The RS485 receivers support up to 256 nodes per bus, and feature full failsafe operation for a T floating, shorted or terminated inputs. n Flexible RS232/RS485/RS422 Interface n An integrated DC/DC boost converter uses a small induc- Software Selectable Multiprotocol Interface Ports n tor and one capacitor, eliminating the need for multiple Point-of-Sale Terminals n supplies for driving RS232 levels. Cable Repeaters n L, LT, LTC, LTM, Linear Technology, the Linear logo and Module are registered trademarks of Protocol Translators Linear Technology Corporation. All other trademarks are the property of their respective owners. n PROFIBUS-DP Networks Typical a T RS485 Mode with Duplex Control RS232 Mode Mixed Mode with RS485 Termination 1.7V TO V 3V TO 5.5V 1.7V TO V 3V TO 5.5V 1.7V TO V 3V TO 5.5V CC CC CC 470nF 470nF 470nF 22H 22H 22H 2.2F 2.2F 2.2F 2.2F 2.2F 2.2F V CAP SW V V CAP SW V V CAP SW V L CC L CC L CC RS485 LTC2872 LTC2872 RS485 LTC2872 H/F TE485-1 FULL HALF OFF ON Y1 DY1 Y1 Y1 DUPLEX TERMINATION DY1 120 Z1 DY1 DZ1 Z1 Z1 RA1 A1 A1 A1 RA1 120 RA1 B1 B1 RB1 B1 DY2 Y2 DY2 Y2 Y2 DY2 Z2 DZ2 Z2 DZ2 Z2 RA2 A2 RA2 A2 A2 RA2 B2 RB2 B2 RB2 B2 V V V V V V DD EE DD EE DD EE 2.2F 2.2F 2.2F 2.2F 2.2F 2.2F 2872 TA01 2872f 1 ions pplica ions pplica ion uresLTC2872 a Te Maxi Mu M r a T p in c F T (Note 1) TOP VIEW Input Supplies V , V ..................................................... 0.3V to 7V CC L 38 37 36 35 34 33 32 Generated Supplies V 1 31 V CC CC V ................................................ V 0.3V to 7.5V DD CC A1 2 30 A2 V .........................................................0.3V to 7.5V EE B1 3 29 B2 V V ..............................................................15V DD EE Y1 4 28 Y2 SW ........................................... 0.3V to (V + 0.3V) DD GND 5 27 GND CAP ............................................. 0.3V to (V 0.3V) EE Z1 6 26 Z2 39 A1, A2, B1, B2, Y1, Y2, Z1, Z2 ......................15V to 15V DY1 7 25 DY2 V EE DZ1 8 24 DZ2 DY1, DY2, DZ1, DZ2, RXEN1, RXEN2, DXEN1, DXEN2, RXEN1 9 23 RXEN2 LB, H/F, TE485 1, TE485 2, DXEN1 10 22 DXEN2 485/232 1, 485/232 2 ................................ 0.3V to 7V TE485 1 11 21 V CC FEN, RA1, RA2, RB1, RB2 ...............0.3V to (V + 0.3V) L TE485 2 12 20 V DD Differential Enabled Terminator Voltage 13 14 15 16 17 18 19 (A1-B1 or A2-B2 or Y1-Z1 or Y2-Z2) .....................6V Operating Temperature LTC2872C ................................................ 0C to 70C UHF PACKAGE LTC2872I .............................................40C to 85C 38-LEAD (5mm 7mm) PLASTIC QFN T = 125C, = 34.7C/W Storage Temperature Range .................. 65C to 125C JMAX JA EXPOSED PAD (PIN 39) IS V , MUST BE SOLDERED TO PCB EE o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC2872CUHF PBF LTC2872CUHF TRPBF 2872 38-Lead (5mm 7mm) Plastic QFN 0C to 70C LTC2872IUHF PBF LTC2872IUHF TRPBF 2872 38-Lead (5mm 7mm) Plastic QFN 40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: