LTC490 LINER

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Technical content

n Low Power: ICC = 300µA Typical n Designed for RS485 or RS422 Applications n Single 5V Supply n –7V to 12V Bus Common-Mode Range Permits ± 7V Ground Difference Between Devices on the Bus n Thermal Shutdown Protection n Power-Up/Down Glitch-Free Driver Outputs Permit Live Insertion or Removal of Package n Driver Maintains High Impedance with the Power Off n Combined Impedance of a Driver Output and Receiver Allows up to 32 Transceivers on the Bus n 70mV Typical Input Hysteresis n 28ns Typical Driver Propagation Delays with 5ns Skew n Pin Compatible with the SN75179 The LTC490 is a low power differential bus/line transceiver designed for multipoint data transmission standard RS485 applications with extended common-mode range (12V to –7V). It also meets the requirements of RS422. The CMOS design offers significant power savings over its bipolar counterpart without sacrificing ruggedness against overload or ESD damage. Excessive power dissipation caused by bus contention or faults is prevented by a thermal shutdown circuit which forces the driver outputs into a high impedance state. The receiver has a fail safe feature which guarantees a high output state when the inputs are left open. Both AC and DC specifications are guaranteed from 0°C to 70°C and 4.75V to 5.25V supply voltage range. USA OPPLICATI n Low Power RS485/RS422 Transceiver n Level Translator UA OPPLICATITYPICAL LTC490 • TA01 120Ω 120Ω 120Ω 120Ω

4000 FT BELDEN 9841

R DR D 3

(Note 1) Operating Temperature Range A UGWA WU WARBSOLUTEX I T I S WU UPACKAGE/ORDER I FOR ATIO TJMAX = 125°C, θJA = 100°C/ W (N8) TJMAX = 150°C, θJA = 150°C/ W (S8) N8 PACKAGE 8-LEAD PLASTIC DIP S8 PACKAGE 8-LEAD PLASTIC SOIC TOP VIEW VCC R D GND A B Z Y R D ORDER PART NUMBER S8 PART MARKING LTC490CN8 LTC490CS8 LTC490IN8 LTC490IS8 490 490I ELECTRICAL C CHARA TERISTICSCD VCC = 5V ± 5% SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VOD1 Differential Driver Output Voltage (Unloaded) I O = 0 l 5V VOD2 Differential Driver Output Voltage (with Load) R = 50 Ω (RS422) l 2V R = 27Ω (RS485) (Figure 1) l 1.5 5 V ΔVOD Change in Magnitude of Driver Differential Output R = 27 Ω or R = 50Ω (Figure 1) l 0.2 V Voltage for Complementary Output States VOC Driver Common-Mode Output Voltage R = 27 Ω or R = 50Ω (Figure 1) l 3V Δ VOC Change in Magnitude of Driver Common Mode R = 27 Ω or R = 50Ω (Figure 1) l 0.2 V Output Voltage for Complementary Output States VIH Input High Voltage (D) l 2.0 V VIL Input Low Voltage (D) l 0.8 V lIN1 Input Current (D) l ± 2 µA lIN2 Input Current (A, B) V CC = 0V or 5.25V VIN = 12V l 1m A VIN = –7V l – 0.8 mA VTH Differential Input Threshold Voltage for Receiver –7V ≤ VCM ≤ 12V l –0.2 0.2 V ΔVTH Receiver Input Hysteresis V CM = 0V l 70 mV VOH Receiver Output High Voltage I O = –4mA, VID = 0.2V l 3.5 V VOL Receiver Output Low Voltage I O = 4mA, VID = – 0.2V l 0.4 V IOZR Three-State Output Current at Receiver V CC = Max 0.4V ≤ VO ≤ 2.4V l ± 1 µA ICC Supply Current No Load; D = GND or V CC l 300 500 µA RIN Receiver Input Resistance –7V ≤ VO ≤ 12V l 12 k Ω IOSD1 Driver Short-Circuit Current, VOUT = High V O = – 7V l 100 250 mA IOSD2 Driver Short-Circuit Current, VOUT = Low V O = 12V l 100 250 mA IOSR Receiver Short-Circuit Current 0V ≤ VO ≤ VCC l 78 5 m A IOZ Driver Three-State Output Current V O = –7V to 12V l ± 2 ±200 µA Consult factory for Military grade parts.

VCC = 5V ± 5% The l denotes specifications which apply over the full operating temperature range. Note 1: Absolute maximum ratings are those beyond which the safety of the device cannot be guaranteed. Note 2: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified. Note 3: All typicals are given for V CC = 5V and Temperature = 25°C. S UGC CHARA TERISTICSWITCHI SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS tPLH Driver Input to Output R DIFF = 54Ω , CL1 = CL2 = 100pF (Figures 2, 3) l 10 30 50 ns tPHL Driver Input to Output R DIFF = 54Ω , CL1 = CL2 = 100pF (Figures 2, 3) l 10 30 50 ns tSKEW Driver Output to Output R DIFF = 54Ω , CL1 = CL2 = 100pF (Figures 2, 3) l 5n s tr, tf Driver Rise or Fall Time R DIFF = 54Ω , CL1 = CL2 = 100pF (Figures 2, 3) l 55 2 5 n s tPLH Receiver Input to Output R DIFF = 54Ω , CL1 = CL2 = 100pF (Figures 2, 4) l 40 70 150 ns tPHL Receiver Input to Output R DIFF = 54Ω , CL1 = CL2 = 100pF (Figures 2, 4) l 40 70 150 ns tSKD  tPLH – tPHL Differential Receiver Skew R DIFF = 54Ω , CL1 = CL2 = 100pF (Figures 2, 4) l 13 ns CCHARA TERISTICSUWATYPICALP E RFOR CE Driver Output High Voltage vs Driver Differential Output Voltage Driver Output Low Voltage vs Output Current vs Output Current Output Current OUTPUT VOLTAGE (V) OUTPUT CURRENT (mA) –24 – 4 8 –72 –96 1234 LTC490 • TPC01 TA = 25°C OUTPUT VOLTAGE (V) OUTPUT CURRENT (mA) 1234 LTC490 • TPC02 TA = 25°C OUTPUT VOLTAGE (V) OUTPUT CURRENT (mA) 1234 LTC490 • TPC03 TA = 25°C TEMPERATURE (°C ) –50 SUPPLY CURRENT (µA) 310 320 330 340 350 0 50 100 LTC490 • TPC06 TEMPERATURE (°C ) –50 INPUT THRESHOLD VOLTAGE (V) 1.55 1.57 1.59 1.61 1.63 0 50 100 LTC490 • TPC04 TTL Input Threshold vs Temperature Driver Skew vs Temperature Supply Current vs Temperature TEMPERATURE (°C ) –50 TIME (ns) 0 50 100 LTC490 • TPC05

capacitance will load down the bus. UPACKAGE DESCRIPTIO Dimensions in inches (millimeters) unless otherwise noted. Figure 11. ESD Protection with TransZorbs