LTC1334 Single 5V RS232/RS485 Multiprotocol Transceiver FEATURES DESCRIPTIO n Four RS232 Transceivers or Two RS485 The LTC 1334 is a low power CMOS bidirectional trans- Transceivers on One Chip ceiver featuring two reconfigurable interface ports. It can n Operates from a Single 5V Supply be configured as two RS485 differential ports, as two dual n Withstands Repeated 10kV ESD Pulses RS232 single-ended ports or as one RS485 differential n Uses Small Charge Pump Capacitors: 0.1m F port and one dual RS232 single-ended port. An onboard n Low Supply Current: 8mA Typical charge pump requires four 0.1m F capacitors to generate n 10m A Supply Current in Shutdown boosted positive and negative supplies, allowing the RS232 n Self-Testing Capability in Loopback Mode drivers to meet the RS232 5V output swing requirement n Power-Up/Down Glitch-Free Outputs with only a single 5V supply. A shutdown mode reduces n Driver Maintains High Impedance in Three-State, the I supply current to 10m A. CC Shutdown or with Power Off The RS232 transceivers are in full compliance with RS232 n Thermal Shutdown Protection specifications. The RS485 transceivers are in full compli- n Receiver Inputs Can Withstand 25V ance with RS485 and RS422 specifications. All interface drivers feature short-circuit and thermal shutdown pro- U tection. An enable pin allows RS485 driver outputs to be APPLICATIO S forced into high impedance, which is maintained even n Low Power RS485/RS422/RS232/EIA562 Interface when the outputs are forced beyond supply rails or power n Software-Selectable Multiprotocol Interface Port is off. Both driver outputs and receiver inputs feature n Cable Repeaters 10kV ESD protection. A loopback mode allows the driver n Level Translators outputs to be connected back to the receiver inputs for diagnostic self-test. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIO 2 1 28 27 27 28 1 2 3 3 LTC1334 LTC1334 26 26 V V CC1 CC2 13 4 5V 5V 24 17 RS485 INTERFACE 5 12 RX OUT RX OUT 23 18 120W DR ENABLE 120W DR ENABLE 11 6 22 19 DR IN 10 DR IN 7 4000-FT 24-GAUGE TWISTED PAIR 9 21 21 8 5V 5V 5V 5V 8 20 20 9 0V 5V 0V 5V RS232 INTERFACE 4 24 19 11 RX OUT DR IN 18 10 5 25 DR IN RX OUT 17 6 22 13 RX OUT DR IN 16 12 7 23 RX OUT DR IN 15 14 14 15 ALL CAPACITORS: 0.1m F MONOLITHIC CERAMIC TYPE LTC1334 TA01 1 U ULTC1334 AB OLUEXAI U RAT GS / S T I PACKAGE ORDER I FOR ATIO (Note 1) TOP VIEW ORDER PART Supply Voltage (V ) ............................................. 6.5V CC + + NUMBER Input Voltage C1 1 28 C2 C1 2 27 C2 Drivers ................................... 0.3V to (V + 0.3V) CC V 3 26 V DD CC Receivers ............................................. 25V to 25V LTC1334CG A1 4 25 R B1 ON/OFF, LB, SEL1, SEL2 ........ 0.3V to (V + 0.3V) LTC1334CNW CC B1 5 24 R A1 Y1 6 23 D /DE1 Output Voltage Z1 LTC1334CSW Z1 7 22 D Y1 Drivers ................................................. 18V to 18V LTC1334IG SEL1 8 21 LB Receivers ............................... 0.3V to (V + 0.3V) LTC1334ISW CC SEL2 9 20 ON/OFF Short-Circuit Duration Z2 10 19 D Y2 Y2 11 18 D /DE2 Z2 Output ........................................................ Indefinite B2 12 17 R + + A2 V , V , C1 , C1 , C2 , C2 .......................... 30 sec DD EE A2 13 16 R B2 Operating Temperature Range GND 14 15 V EE Commercial ........................................... 0 C to 70 C G PACKAGE NW PACKAGE 28-LEAD PLASTIC SSOP 28-LEAD PDIP WIDE Industrial ............................................ 40 C to 85 C SW PACKAGE Storage Temperature Range ................ 65 C to 150 C 28-LEAD PLASTIC SO WIDE Lead Temperature (Soldering, 10 sec)................ 300 C T = 125 C, q = 90 C/W (G) JMAX JA T = 125 C, q = 56 C/W (NW) JMAX JA T = 125 C, q = 85 C/W (SW) JMAX JA Consult factory for Military grade parts. DC ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. V = 5V, C1 = C2 = C3 = C4 = 0.1m F (Notes 2, 3) A CC SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS RS485 Driver (SEL1 = SEL2 = High) V Differential Driver Output Voltage (Unloaded) I = 0 l 6V OD1 O V Differential Driver Output Voltage (With Load) Figure 1, R = 50W (RS422) l 2.0 6 V OD2 Figure 1, R = 27W (RS485) l 1.5 6 V D V Change in Magnitude of Driver Differential Figure 1, R = 27W or R = 50W l 0.2 V OD Output Voltage for Complementary Output States V Driver Common Mode Output Voltage Figure 1, R = 27W or R = 50W l 3V OC D V Change in Magnitude of Driver Common Mode Figure 1, R = 27W or R = 50W l 0.2 V OC Output Voltage for Complementary Output States I Driver Short-Circuit Current 7V V 12V, V = High l 35 250 mA OSD O O 7V V 12V, V = Low (Note 4) l 10 250 mA O O I Three-State Output Current (Y, Z) 7V V 12V l 5 500 m A OZD O RS232 Driver (SEL1 = SEL2 = Low) V Output Voltage Swing Figure 4, R = 3k, Positive l 5 6.5 V O L = 3k, Negative l 5 6.5 V Figure 4, R L I Output Short-Circuit Current V = 0V l 60 mA OSD O Driver Inputs and Control Inputs V Input High Voltage D, DE, ON/OFF, SEL1, SEL2, LB l2V IH V Input Low Voltage D, DE, ON/OFF, SEL1, SEL2, LB l 0.8 V IL I Input Current D, SEL1, SEL2 l 10 m A IN DE, ON/OFF, LB l 4 15 m A 2 U WU U W W W