LL A (141) TXD A (103) TXD B SCTE A (113) SCTE B TXC A (114) TXC B RXC A (115) RXC B RXD A (104) RXD B TM A (142) SGND (102) SHIELD (101) RL A (140) RTS A (105) RTS B DTR A (108) DTR B DCD A (109) DCD B DSR A (107) DSR B CTS A (106) CTS B LTC1344 Software-Selectable Cable Terminator FEATURES DESCRIPTIO n Software-Selectable Cable Termination for: The LTC 1344 features six software-selectable RS232 (V.28) multiprotocol cable terminators. Each terminator can be RS423 (V.10) configured as an RS422 (V.11) 100W minimum differen- RS422 (V.11) tial load, V.35 T-network load or an open circuit for use RS485 with RS232 (V.28) or RS423 (V.10) transceivers that RS449 provide their own termination. When combined with the EIA530 LTC1343, the LTC1344 forms a complete software-select- EIA530-A able multiprotocol serial port. A data bus latch feature V.35 allows sharing of the select lines between multiple inter- V.36 face ports. X.21 The LTC1344 is available in a 24-lead SSOP. n Outputs Wont Load the Line with Power Off , LTC and LT are registered trademarks of Linear Technology Corporation. U APPLICATIO S n Data Networking n CSU and DSU n Data Routers TYPICAL APPLICATION CTS DSR DCD DTR RTS RL TM RXD RXC TXC SCTE TXD LL Daisy-Chained Control Outputs LTC1343 LTC1343 D2 D1 D4 D3 D4 D3 D2 D1 R4 R3 R2 R1 R4 R3 R2 R1 LTC1344 13 5 22 6 10 8 23 20 19 4 21 1 7 25 16 3 9 17 12 15 11 24 14 2 18 DB-25 CONNECTOR 1344 TA01 1 U ULTC1344 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW Positive Supply Voltage (V )................................... 7V ORDER PART CC M0 1 24 M1 Negative Supply Voltage (V ) ........................... 13.2V NUMBER EE V 2 23 M2 EE Input Voltage (Logic Inputs) .... V 0.3V to V + 0.3V EE CC R1C 3 22 DCE/DTE LTC1344CG Input Voltage (Load Inputs) .................................. 18V R1B 4 21 LATCH LTC1344IG Operating Temperature Range R1A 5 20 R6B LTC1344C ............................................... 0 C to 70 C R2A 6 19 R6A LTC1344I........................................... 40 C to 85 C R2B 7 18 R5A Storage Temperature Range ................ 65 C to 150 C R2C 8 17 R5B Lead Temperature (Soldering, 10 sec)................. 300 C R3A 9 16 R4A R3B 10 15 R4B R3C 11 14 V CC GND 12 13 GND G PACKAGE 24-LEAD PLASTIC SSOP T = 150 C, q = 100 C/W JMAX JA Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 . A V = 5V 5%, V = 5V 5%, T = T to T (Notes 2, 3) unless otherwise noted. CC EE A MIN MAX SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Supplies I Supply Current All Digital Pins = GND or V l 200 700 m A CC CC Terminator Pins R Differential Mode Impedance All Loads (Figure 1), 2V V 2V (Commercial) l 90 103 110 W V.35 CM Common Mode Impedance All Loads (Figure 2), 2V V 2V (Commercial) l 135 153 165 W CM All Loads (Figure 1), 2V V 2V (Industrial) l 90 104 125 W CM All Loads (Figure 2), 2V V 2V (Industrial) l 130 153 170 W CM R Differential Mode Impedance All Loads (Figure 1), 7V V 7V (Commercial) 100 104 W V.11 CM All Loads (Figure 1), V = 0V (Commercial) l 100 104 110 W CM All Loads (Figure 1), V = 0V (Industrial) l 95 104 125 W CM I High Impedance Leakage Current All Loads, 7V V 7V (Commercial) l 1 50 m A LEAK CM Logic Inputs V Input High Voltage All Logic Input Pins l2V IH V Input Low Voltage All Logic Input Pins l 0.8 V IL I Input Current All Logic Input Pins l 10 m A IN Note 1: Absolute Maximum Ratings are those values beyond which the life Note 3: All typicals are given at V = 5V, V = 5V, T = 25 C. CC EE A of a device may be impaired. Note 2: All currents into device pins are positive all currents out of device pins are negative. All voltages are reference to ground unless otherwise specified. 2 U U WWW WU