SN74F1016 16-BIT SCHOTTKY BARRIER DIODE R-C BUS-TERMINATION ARRAY SDFS093 – NOVEMBER 1992 – REVISED DECEMBER 1993 • • • DW PACKAGE (TOP VIEW) Designed to Reduce Reflection Noise Repetitive Peak Forward Current . . . 300 mA 16-Bit Array Structure Suited for Bus-Oriented Systems GND A1 A2 A3 A4 A5 A6 A7 A8 GND description This bus-termination array is designed to reduce reflection noise and minimize ringing on high-performance bus lines. The SN74F1016 features a 16-bit R-C network and Schottky barrier diode array. These Schottky diodes provide clamp-to-ground functionality and serve to minimize overshoot and undershoot of high-speed switching buses. 1 20 2 19 3 18 4 17 5 16 6 15 7 14 8 13 9 12 10 11 GND A16 A15 A14 A13 A12 A11 A10 A9 GND The SN74F1016 is characterized for operation from 0°C to 70°C. schematic diagram GND A16 A15 A14 A13 A12 A11 A10 A9 GND 20 19 18 17 16 15 14 13 12 11 1 2 3 4 5 6 7 8 9 10 GND A1 A2 A4 A5 A7 A8 Resistor = Capacitor = Diode = A3 A6 GND 50 Ω ± 10% 47 pF ± 10%, VR = 2.5 V, f = 1 MHz Schottky Copyright 1993, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 2–1 SN74F1016 16-BIT SCHOTTKY BARRIER DIODE R-C BUS-TERMINATION ARRAY SDFS093 – NOVEMBER 1992 – REVISED DECEMBER 1993 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Steady-state reverse voltage, VR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Continuous forward current, IF: Any D terminal from GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 mA Total through all GND terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 mA Repetitive peak forward current, IFRM‡: Any D terminal from GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 mA Total through all GND terminals . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 A Continuous total power dissipation at (or below) 25°C free-air temperature . . . . . . . . . . . . . . . . . . . . 500 mW Operating free-air temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. ‡ These values apply for tw ≤ 100 µs, duty cycle ≤ 20%. electrical characteristics over recommended operating free-air temperature range (unless otherwise noted) single-diode operation (see Note 1) MIN TYP† PARAMETER TEST CONDITIONS MAX IR VFM Static reverse current Peak forward voltage VR = 7 V IF = 200 mA Total capacitance VR = 0 VR = 2 V 80 Ct VR = 3 V 55 2 1.25 UNIT µA V 60 pF † All typical values are at TA = 25°C. NOTE 1: Test conditions and limits apply separately to each of the diodes. The diodes not under test are open-circuited during the measurement of these characteristics. multiple-diode operation PARAMETER TEST CONDITIONS TYP† MAX 10 50 MIN TYP† MAX 8 10 MIN TYP† MAX 0.7 0.8 MIN Ix Internal crosstalk current Total GND current = 1.2 A, See Note 2 NOTE 2: Ix is measured under the following conditions with one diode static, all others switching: Switching diodes: tw = 100 µs, duty cycle = 20%; Static diode: VR = 5 V; the static diode input current is the internal crosstalk current Ix. UNIT µA switching characteristics, TA = 25°C PARAMETER trr Reverse recovery time TEST CONDITIONS IF = 10 mA, IRM(REC) = 10 mA, IR(REC) = 1 mA, RL = 100 Ω UNIT ns undershoot characteristics PARAMETER VUS 2–2 Undershoot voltage TEST CONDITIONS tf = 2 ns, tw = 50 ns, VIH = 5 V, VIL = 0, ZS = 25 Ω, ZO = 50 Ω, L = 36-inch coaxial cable POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 UNIT V SN74F1016 16-BIT SCHOTTKY BARRIER DIODE R-C BUS-TERMINATION ARRAY SDFS093 – NOVEMBER 1992 – REVISED DECEMBER 1993 APPLICATION INFORMATION Large negative transients occurring at the inputs of memory devices (DRAMs, SRAMs, EPROMs, etc.) or on the CLOCK lines of many clocked devices can result in improper operation of the devices. The SN74F1016 diode termination array helps suppress negative transients caused by transmission line reflections, crosstalk, and switching noise. Diode terminations have several advantages when compared to resistor termination schemes. Split resistor or Thevenin equivalent termination can cause a substantial increase in power consumption. The use of a single resistor to ground to terminate a line usually results in degradation of the output high level, resulting in reduced noise immunity. Series damping resistors placed on the outputs of the driver will reduce negative transients, but they can also increase propagation delays down the line, as a series resistor reduces the output drive capability of the driving device. Diode terminations have none of these drawbacks. The operation of the diode arrays in reducing negative transients is explained in Figure 1. The diode conducts current whenever the voltage reaches a negative value large enough for the diode to turn on. Suppression of negative transients is tracked by the current-voltage characteristic curve for that diode. A typical current voltage for the SN74F1016 is shown in Figure 1. The maximum effectiveness of the diode arrays in suppressing negative transients occurs when they are placed at the end of a line and/or the end of a long stub branching off a main transmission line. The diodes can also be used to reduce the negative transients that occur due to discontinuities in the middle of a line. An example of this is a slot in a backplane that is provided for an add-on card. DIODE FORWARD CURRENT vs DIODE FORWARD VOLTAGE – 100 Variable 1: VIN – Ch1 Linear Sweep: Start 0.000 V Stop – 2.000 V Step – 0.010 V TA = 25°C – 90 I I – Forward Current – mA – 80 – 70 Constants: VHI –Vs1 VLO –Vs2 – 60 3.5000 V 0.0000 V – 50 – 40 – 30 – 20 – 10 0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 VF – Forward Voltage – V Figure 1 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 2–3 SN74F1016 16-BIT SCHOTTKY BARRIER DIODE R-C BUS-TERMINATION ARRAY SDFS093 – NOVEMBER 1992 – REVISED DECEMBER 1993 ZO = 50 Ω Length = 36 in S1 ZS = 25Ω (a) UNDERSHOOT TEST SETUP 218.500 ns 243.500 ns 268.500 ns S1 Open S1 Closed Vmarker 1 Vmarker 2 – 2.0 V Ch. 1 Timebase Vmarker 1 Vmarker 2 = = = = Offset Delay Delta V 1.00 V/div 5.00 ns/div 0.00 V – 640.00 mV (b) SCOPE DISPLAY Figure 2. Undershoot Test Setup and Scope Display 2–4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 = – 20.00 mV = 243.5 ns = – 640.00 mV IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. 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