LTC491IN#PBF Analog Devices

LTC491 Differential Driver and Receiver Pair FEATURES DESCRIPTIO n Low Power: I = 300m A Typical The LTC 491 is a low power differential bus/line trans- CC n Designed for RS485 or RS422 Applications ceiver designed for multipoint data transmission standard n Single 5V Supply RS485 applications with extended common mode range n 7V to 12V Bus Common Mode Range (12V to 7V). It also meets the requirements of RS422. Permits 7V Ground Difference Between Devices The CMOS design offers significant power savings over its on the Bus bipolar counterpart without sacrificing ruggedness against n Thermal Shutdown Protection overload or ESD damage. n Power-Up/-Down Glitch-Free Driver Outputs Permit The driver and receiver feature three-state outputs, with Live Insertion or Removal of Package n the driver outputs maintaining high impedance over the Driver Maintains High Impedance in Three-State or entire common mode range. Excessive power dissipation with the Power Off n caused by bus contention or faults is prevented by a Combined Impedance of a Driver Output and thermal shutdown circuit which forces the driver outputs Receiver Allows up to 32 Transceivers on the Bus n into a high impedance state. 70mV Typical Input Hysteresis n 28ns Typical Driver Propagation Delays with 5ns The receiver has a fail safe feature which guarantees a high Skew for 2.5MB Operation output state when the inputs are left open. n Pin Compatible with the SN75180 Both AC and DC specifications are guaranteed from 0 C to n Available in 14-Lead PDIP and SO Packages 70 C and 4.75V to 5.25V supply voltage range. U APPLICATIO S , LTC and LT are registered trademarks of Linear Technology Corporation. n Low Power RS485/RS422 Transceiver n Level Translator TYPICAL APPLICATIO DE DE 4 9 5 120W 120W D DRIVER RECEIVER R 10 4000 FT 24 GAUGE TWISTED PAIR LTC491 LTC491 12 2 120W 120W R RECEIVER DRIVER D 11 4000 FT 24 GAUGE TWISTED PAIR 3 REB REB LTC491 TA01 491fa 1 U ULTC491 /O ABSOLUTEXAI U RATI GS PACKAGE RDER I FOR ATIO (Note 1) Supply Voltage (V ) ............................................... 12V CC TOP VIEW ORDER PART Control Input Voltages .................... 0.5V to V + 0.5V CC NUMBER NC 1 14 V CC Control Input Currents .......................... 50mA to 50mA R 13 NC R 2 Driver Input Voltages ...................... 0.5V to V + 0.5V CC LTC491CN REB 3 12 A Driver Input Currents ............................ 25mA to 25mA LTC491CS DE 4 11 B Driver Output Voltages .......................................... 14V LTC491IN D 5 10 Z D Receiver Input Voltages ......................................... 14V LTC491IS GND 6 9 Y Receiver Output Voltages ............... 0.5V to V + 0.5V CC GND 7 8 NC Operating Temperature Range N PACKAGE S PACKAGE LTC491C ................................................. 0 C to 70 C 14-LEAD PDIP 14-LEAD PLASTIC SO T = 100 C, q = 90 C/W (N) LTC491I.............................................. 40 C to 85 C JMAX JA T = 100 C, q = 110 C/W (S) JMAX JA Storage Temperature Range ................. 65 C to 150 C Lead Temperature (Soldering, 10 sec).................. 300 C Consult LTC Marketing 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. V = 5V 5% A CC SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Differential Driver Output Voltage (Unloaded) I = 0 l 5V OD1 O V Differential Driver Output Voltage (With load) R = 50W (RS422) l2V OD2 R = 27W (RS485) (Figure 1) l 1.5 5 V D V Change in Magnitude of Driver Differential Output R = 27W or R = 50W (Figure 1) l 0.2 V OD Voltage for Complementary Output States V Driver Common Mode Output Voltage l 3V OC D V Change in Magnitude of Driver Common Mode l 0.2 V OC Output Voltage for Complementary Output States V Input High Voltage D, DE, REB l 2.0 V IH V Input Low Voltage l 0.8 V IL l Input Current l 2 m A IN1 l Input Current (A, B) V = 0V or 5.25V V = 12V l 1.0 mA IN2 CC IN V = 7V l 0.8 mA IN V Differential Input Threshold Voltage for Receiver 7V V 12V l 0.2 0.2 V TH CM D V Receiver Input Hysteresis V = 0V l 70 mV TH CM V Receiver Output High Voltage I = 4mA, V = 0.2V l 3.5 V OH O ID V Receiver Output Low Voltage I = 4mA, V = 0.2V l 0.4 V OL O ID I Three-State Output Current at Receiver V = Max 0.4V V 2.4V l 1 m A OZR CC O I Supply Current No Load D = GND, Outputs Enabled l 300 500 m A CC or V CC Outputs Disabled l 300 500 m A R Receiver Input Resistance 7V V 12V l 12 kW IN CM I Driver Short Circuit Current, V = High V = 7V l 100 250 mA OSD1 OUT O I Driver Short Circuit Current, V = Low V = 12V l 100 250 mA OSD2 OUT O I Receiver Short Circuit Current 0V V V l785 mA OSR O CC I Driver Three-State Output Current V = 7V to 12V l 2 200 m A OZ O 491fa 2 U WU U W W W