LTC1481 Ultralow Power RS485 Transceiver with Shutdown FEATURES DESCRIPTIO n Low Power: I = 120m A Max with Driver Disabled The LTC 1481 is an ultralow power differential line trans- CC n Drivers/Receivers Have 10kV ESD Protection ceiver designed for data transmission standard RS485 n 1m A Quiescent Current in Shutdown Mode applications. It will also meet the requirements of RS422. n High Speed: Up to 2.5Mbits/s Data Rate The CMOS design offers significant power savings over its n I = 500m A Max with Driver Enabled, No Load bipolar counterparts without sacrificing ruggedness against CC n Single 5V Supply overload or ESD damage. Typical quiescent current is only n 7V to 12V Common Mode Range Permits 7V 80m A while operating and less than 1m A in shutdown. Ground Difference Between Devices on the Data Line The driver and receiver feature three-state outputs, with n Thermal Shutdown Protection the driver outputs maintaining high impedance over the n Power Up/Down Glitch-Free Driver Outputs Permit entire common mode range. Excessive power dissipation Live Insertion or Removal of Transceiver caused by bus contention or faults is prevented by a n Driver Maintains High Impedance in Three-State thermal shutdown circuit which forces the driver outputs or with the Power Off into a high impedance state. The receiver has a fail-safe n Up to 32 Transceivers on the Bus feature which guarantees a high output state when the n 30ns Typical Driver Propagation Delays inputs are left open. with 5ns Skew n The LTC1481 is fully specified over the commercial and Pin Compatible with the LTC485 extended industrial temperature range and is available in U 8-pin PDIP and SO packages. APPLICATIO S , LTC and LT are registered trademarks of Linear Technology Corporation. n Battery-Powered RS485/RS422 Applications n Low Power RS485/RS422 Transceiver n Level Translator TYPICAL APPLICATIO Supply Current vs Temperature 350 RO1 V THERMAL SHUTDOWN CC1 300 R WITH DRIVER ENABLED RE1 Rt 250 m DE1 DRIVER ENABLED D 200 DI1 GND1 150 Rt RO2 V CC2 R 100 DRIVER DISABLED RE2 50 DE2 D DI2 GND2 0 LTC1481 TA01 50 25 0 25 75 100 125 150 175 50 TEMPERATURE (C) 1481 TA02 1481fa 1 SUPPLY CURRENT ( A) U ULTC1481 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART Supply Voltage (V ) .............................................. 12V CC TOP VIEW NUMBER Control Input Voltage..................... 0.5V to V + 0.5V CC RO 1 8 V CC Driver Input Voltage....................... 0.5V to V + 0.5V R LTC1481CN8 CC RE B 2 7 Driver Output Voltage ........................................... 14V LTC1481IN8 DE 3 6 A Receiver Input Voltage.......................................... 14V LTC1481CS8 D DI 4 5 GND Receiver Output Voltage ................ 0.5V to V + 0.5V LTC1481IS8 CC Operating Temperature Range N8 PACKAGE S8 PACKAGE S8 PART MARKING 8-LEAD PDIP 8-LEAD PLASTIC SO LTC1481C ....................................... 0 C T 70 C A T = 125 C, q = 130 C/ W (N8) JMAX JA 1481 LTC1481I.................................... 40 C T 85 C T = 125 C, q = 150 C/ W (S8) A JMAX JA 1481I 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. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. V = 5V (Notes 2, 3) unless otherwise noted. 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) l 2.0 V 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 R = 27W or R = 50W , Figure 1 l 3V OC D V Change in Magnitude of Driver Common Mode R = 27W or R = 50W , Figure 1 l 0.2 V OC Output Voltage for Complementary Output States V Input High Voltage DE, DI, RE l2V IH V Input Low Voltage DE, DI, RE l 0.8 V IL I Input Current DE, DI, RE l 2 m A IN1 I Input Current (A, B) DE = 0, V = 0V or 5.25V, V = 12V l 1.0 mA IN2 CC IN DE = 0, V = 0V or 5.25V, V = 7V l 0.8 mA CC 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 45 mV TH CM V Receiver Output High Voltage I = 4mA, V = 200mV l 3.5 V OH O ID V Receiver Output Low Voltage I = 4mA, V = 200mV l 0.4 V OL O ID I Three-State (High Impedance) Output V = Max, 0.4V V 2.4V l 1 m A OZR CC O Current at Receiver R Receiver Input Resistance 7V V 12V l 12 kW IN CM I Supply Current No Load, Output Enabled l 300 500 m A CC No Load, Output Disabled l 80 120 m A I Supply Current in Shutdown Mode DE = 0, RE = V 110 m A SHDN CC I Driver Short-Circuit Current, V = HIGH 7V V 12V l 35 250 mA OSD1 OUT O I Driver Short-Circuit Current, V = LOW 7V V 12V l 35 250 mA OSD2 OUT O I Receiver Short-Circuit Current 0V V V l785mA OSR O CC 1481fa 2 U WWW