LTC1688/LTC1689 100Mbps RS485 Hot Swapable Quad Drivers DESCRIPTIO FEATURES n Ultrahigh Speed: 100Mbps The LTC 1688/LTC1689 are ultrahigh speed, differential n Guaranteed Propagation Delay: 8ns 4ns bus/line drivers that can operate at data rates up to Over Temperature 100Mbps. Propagation delay is guaranteed at 8ns 4ns n Low Channel-to-Channel Skew: 500ps Typ over the full operating temperature range. These devices TM n Hot Swap Capable operate over the full RS485 common mode range (7V n 50Mbps Operation with V = 3V to 12V), and also meet RS422 requirements. DD n Low t /t Skew: 500ps Typ PLH PHL The driver outputs are Hot Swap capable, maintaining n Driver Outputs Maintain High Impedance in backplane data integrity during board insertion and Three-State or with Power Off removal. The drivers feature three-state outputs, maintain- n Short-Circuit Protected: 3mA Typ Output Current ing high impedance over the entire common mode range for an Indefinite Short ( 7V to 12V). Outputs also remain high impedance during n Thermal Shutdown Protected power-up and with the power off. A short-circuit feature n Single 5V or 3V Supply detects bus contention and substantially reduces driver n Pin Compatible with LTC486/LTC487 output current. Thermal shutdown circuitry protects the parts from excessive power dissipation. U APPLICATIO S The LTC1688 allows all four drivers to be enabled together, while the LTC1689 allows two drivers at a time to be n High Speed RS485 Twisted-Pair Drivers enabled. n High Speed Backplane Drivers n Complementary Clock Drivers The LTC1688/LTC1689 operate from a single 5V or 3V n STS-1/OC-1 Data Drivers supply and draw only 9mA of supply current. n SCSI Drivers , LTC and LT are registered trademarks of Linear Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation. TYPICAL APPLICATIO 20ns Pulse Across 100 Feet of Category 5 UTP 2V/DIV DRIVER INPUT 50Mbps RS485 Data Connection 2V/DIV DRIVER OUTPUTS 100W 100W DRIVER RECEIVER CABLE DELAY 100 FT CATEGORY 5 UTP 2V/DIV RECEIVER INPUT 1/4 LTC1688 1/4 LTC1518 1688/89 TA01 5V/DIV RECEIVER OUTPUT 20ns/DIV 1688/89 TA02 16889fa 1 U ULTC1688/LTC1689 O ABS LUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) Supply Voltage (V ) ................................................ 7V DD TOP VIEW ORDER PART Enable Input Voltages ................. 0.5V to (V + 0.5V) DD NUMBER DI1 1 16 V DD Enable Input Currents ..................... 100mA to 100mA DO1A 2 15 DI4 Driver Input Voltages .................. 0.5V to (V + 0.5V) LTC1688CS DD DO1B 3 14 DO4A Driver Output Voltages ................. (12V + V ) to 12V LTC1689CS DD EN (EN12*) 4 13 DO4B Driver Input Currents ...................... 100mA to 100mA LTC1688IS DO2B 5 12 ENB (EN34*) Short-Circuit Duration (V : 7V to 10V) ...... Indefinite DO2A 6 11 DO3B LTC1689IS OUT Operating Temperature Range DI2 7 10 DO3A GND 8 9 DI3 LTC1688C/LTC1689C ............................. 0 C to 70 C LTC1688I/LTC1689I .......................... 40 C to 85 C S PACKAGE 16-LEAD PLASTIC SO Storage Temperature Range ................ 65 C to 150 C *LTC1689 ONLY Lead Temperature (Soldering, 10 sec)................. 300 C T = 150 C, q = 90 C/ W JMAX JA Consult factory for parts specified with wider operating temperature ranges. DC ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. A SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V = 5V, Per Driver, T = 25 C, Unless Otherwise Noted (Note 2) DD A V Differential Driver Output (Unloaded) I = 0 l V V OD1 OUT DD V Differential Driver Output (With Load) R = 50W (RS422) l2V OD2 R = 25W (RS485), Figure 1 l 1.5 3.0 V D V Change in Magnitude of Driver Differential R = 25W or 50W , Figure 1 l 0.2 V OD Output Voltage for Complementary Output States V Driver Common Mode Output Voltage R = 25W or 50W , Figure 1 l 23 V OC D V Change in Magnitude of Driver Common R = 25W or 50W , Figure 1 l 0.2 V OC Mode Output Voltage for Complementary Output States V Input High Voltage EN, ENB, EN12, EN34, DI l2V IH V Input Low Voltage EN, ENB, EN12, EN34, DI l 0.8 V IL I Input Current EN, ENB, EN12, EN34, DI l 1 m A IN1 I Three-State (High Impedance) V = 7V to 12V l 2 200 m A OZ OUT Output Current I Supply Current of Entire Device No Load, Digital Input Pins = 0V or V l 918 mA DD DD I Driver Short-Circuit Current, V = HIGH V = 7V to 10V l 20 mA OSD1 OUT OUT I Driver Short-Circuit Current, V = LOW V = 7V to 10V l 20 mA OSD2 OUT OUT V = 3V, Per Driver, T = 25 C, Unless Otherwise Noted (Note 2) DD A V Differential Driver Output (Unloaded) I = 0 l V V OD1 OUT DD V Differential Driver Output (With Load) R = 50W (RS422) 1.5 V OD2 R = 25W (RS485), Figure 1 l 0.65 2.0 V D V Change in Magnitude of Driver Differential R = 25W or 50W , Figure 1 0.1 V OD Output Voltage for Complementary Output States V Driver Common Mode Output Voltage R = 25W or 50W , Figure 1 1.3 V OC 16889fa 2 U WU U W W W