LTC490 Differential Driver and Receiver Pair FEATURES DESCRIPTIO n Low Power: I = 300m A Typical The LTC 490 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 Excessive power dissipation caused by bus contention or Live Insertion or Removal of Package n faults is prevented by a thermal shutdown circuit which Driver Maintains High Impedance with the forces the driver outputs into a high impedance state. The Power Off n receiver has a fail safe feature which guarantees a high Combined Impedance of a Driver Output and output state when the inputs are left open. Receiver Allows up to 32 Transceivers on the Bus n 70mV Typical Input Hysteresis Both AC and DC specifications are guaranteed from 0 C to n 28ns Typical Driver Propagation Delays with 70 C and 4.75V to 5.25V supply voltage range. 5ns Skew for 2.5MB Operation , LTC and LT are registered trademarks of Linear Technology Corporation. n Pin Compatible with the SN75179 n Available in 8-Lead PDIP and SO Packages U APPLICATIO S n Low Power RS485/RS422 Transceiver n Level Translator TYPICAL APPLICATIO LTC490 LTC490 5 3 120W 120W D DRIVER RECEIVER R 6 4000 FT BELDEN 9841 8 2 120W 120W R RECEIVER DRIVER D 7 4000 FT BELDEN 9841 LTC490 TA01 490fb 1 U ULTC490 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART Supply Voltage (V ) ............................................... 12V TOP VIEW CC NUMBER Driver Input Currents ........................... 25mA to 25mA V 1 8 A CC R Driver Input Voltages ...................... 0.5V to V + 0.5V CC R 2 7 B LTC490CN8 Driver Output Voltages .......................................... 14V D 3 6 Z LTC490CS8 D Receiver Input Voltages ......................................... 14V GND 5 Y 4 LTC490IN8 Receiver Output Voltages ............... 0.5V to V + 0.5V CC LTC490IS8 N8 PACKAGE 8-LEAD PDIP Operating Temperature Range S8 PACKAGE S8 PART MARKING LTC490C ................................................ 0 C to 70 C 8-LEAD PLASTIC SO LTC490I............................................. 40 C to 85 C 490 T = 125 C, q = 100 C/ W (N8) JMAX JA T = 150 C, q = 150 C/W (S8) JMAX JA Storage Temperature Range ................. 65 C to 150 C 490I 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 specificatiions 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 l V Differential Driver Output Voltage (with Load) R = 50W (RS422) 2V OD2 l R = 27W (RS485) (Figure 1) 1.5 5 V l D V Change in Magnitude of Driver Differential Output R = 27W or R = 50W (Figure 1) 0.2 V OD Voltage for Complementary Output States l V Driver Common Mode Output Voltage R = 27W or R = 50W (Figure 1) 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 l V Input High Voltage (D) 2.0 V IH l V Input Low Voltage (D) 0.8 V IL l Input Current (D) l 2 m A IN1 l l Input Current (A, B) V = 0V or 5.25V V = 12V 1mA IN2 CC IN l V = 7V 0.8 mA IN V Differential Input Threshold Voltage for Receiver 7V V 12V l 0.2 0.2 V TH CM l D V Receiver Input Hysteresis V = 0V 70 mV TH CM l V Receiver Output High Voltage I = 4mA, V = 0.2V 3.5 V OH O ID V Receiver Output Low Voltage I = 4mA, V = 0.2V l 0.4 V OL O ID l I Three-State Output Current at Receiver V = Max 0.4V V 2.4V 1 m A OZR CC O l I Supply Current No Load D = GND or V 300 500 m A CC CC l R Receiver Input Resistance 7V V 12V 12 kW IN O l I Driver Short-Circuit Current, V = High V = 7V 100 250 mA OSD1 OUT O l I Driver Short-Circuit Current, V = Low V = 12V 100 250 mA OSD2 OUT O I Receiver Short-Circuit Current 0V V V l 785 mA OSR O CC l I Driver Three-State Output Current V = 7V to 12V 2 200 m A OZ O 490fb 2 U WWW