LTC1520 50Mbps Precision Quad Line Receiver DESCRIPTION FEATURES n Precision Propagation Delay: 18ns 3ns Over The LTC 1520 is a high speed, precision differential line Temperature receiver that can operate at data rates as high as 50Mbps. n Data Rate: 50Mbps A unique architecture provides very stable propagation n Low t /t Skew: 500ps Typ delays and low skew over a wide input common mode, PLH PHL n Low Channel-to-Channel Skew: 400ps Typ input overdrive and ambient temperature range. Propaga- n Rail-to-Rail Input Common Mode Range tion delay is 18ns 3ns, while typically t /t skew is PLH PHL n High Input Resistance: 18k, Even When Unpowered 500ps and channel-to-channel skew is 400ps. n Hot Swap Capable Each receiver translates differential input levels (V ID n Can Withstand Input DC Levels of 10V 100mV) into valid CMOS and TTL output levels. Its high n Short-Circuit Protected input resistance ( 18k) allows many receivers to be con- n Single 5V Supply nected to the same driver. The receiver outputs go into a n LVDS Compatible high impedance state when disabled. n Will Not Oscillate with Slow Input Signals Protection features include thermal shutdown and a con- U trolled maximum short-circuit current (50mA max) that APPLICATIONS does not oscillate in and out of short-circuit mode. Input n High Speed Backplane Interface resistance remains 18k when the device is unpowered or n Line Collision Detector disabled, thus allowing the LTC1520 to be hot swapped into n PECL and LVDS Line Receivers a backplane without loading the data lines. n Level Translator The LTC1520 operates from a single 5V supply and draws n Ring Oscillator 12mA of supply current. The part is available in a 16-lead n Tapped Delay Line narrow SO package. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATION High Speed Backplane Receiver Propagation Delay Guaranteed to Fall Within Shaded Area ( 3ns) LTC1520 + RECEIVER + INPUT V = IN V = 500mV ID 1V/DIV + RECEIVER OUTPUT V = OUT V = 5V DD 5V/DIV + 5V 3.3k 50 51021503250435045 TIME (ns) 0.01m F 3.3k LTC1520 TA02 1520 TA01 1 U ULTC1520 ABSOLUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW Supply Voltage ....................................................... 10V ORDER PART Digital Input Currents ..................... 100mA to 100mA NUMBER B1 1 16 V DD Digital Input Voltages ............................... 0.5V to 10V A1 2 15 B4 LTC1520CS OUT 1 3 14 A4 Receiver Input Voltages ........................................ 10V ENABLE 4 13 OUT 4 Receiver Output Voltages ............. 0.5V to V + 0.5V DD OUT 2 5 12 NC Short-Circuit Duration .................................... Indefinite A2 6 11 OUT 3 Operating Temperature Range .................... 0 C to 70 C B2 7 10 A3 Storage Temperature Range ................ 65 C to 150 C GND 8 9 B3 Lead Temperature (Soldering, 10 sec)................. 300 C S PACKAGE 16-LEAD PLASTIC SO T = 150 C, q = 90 C/ W JMAX JA Consult factory for Industrial and Military grade parts. DC ELECTRICAL CHARACTERISTICS V = 5V 5% (Notes 2, 3) per receiver, unless otherwise noted. DD SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Input Common Mode Voltage A, B Inputs l 0.2 V + 0.2 V CM DD V Input High Voltage Enable Input l2V IH V Input Low Voltage Enable Input l 0.8 V IL I Input Current Enable Input l 1 1 m A IN1 I Input Current (A, B) V , V = 5V l 250 m A IN2 A B V , V = 0 l 250 m A A B R Input Resistance (Figure 5) 0.2V V V + 0.2V l 18 kW IN CM DD C A, B Input Capacitance (Note 4) 3 pF IN V Open-Circuit Input Voltage (Figure 5) V = 5V (Note 4) l 3.2 3.3 3.4 V OC DD V Differential Input Threshold Voltage 0.2V < V < V + 0.2V l 0.1 0.1 V ID(MIN) CM DD dV Input Hysteresis V = 2.5V l 20 mV ID CM V Output High Voltage I = 4mA, V = 0.1V, V = 5V l 4.6 V OH OUT ID DD V Output Low Voltage I = 4mA, V = 0.1V, V = 5V l 0.4 V OL OUT ID DD I Three-State Output Current 0V V V l 10 10 m A OZR OUT DD I Total Supply Current All 4 Receivers V 0.1V, No Load, Enable = 5V l 12 20 mA DD ID I Short-Circuit Current V = 0V, V = V l 50 50 mA OSR OUT OUT DD CMRR Common Mode Rejection Ratio V = 2.5V, f = 25MHz 45 dB CM 2 U WU U W W W