HS-1412RH S E M I C O N D U C T O R Radiation Hardened, Quad, High Speed, Low Power, Video Closed Loop Buffer August 1996 Features Description * Electrically Screened to SMD#5962F9683401VCA The HS-1412RH is a radiation hardened quad closed loop buffer featuring user programmable gain and high speed performance. Manufactured on Harris' proprietary complementary bipolar UHF1 (DI bonded wafer) process, this device offers wide -3dB bandwidth of 340MHz, very fast slew rate, excellent gain flatness and high output current. These devices are QML approved and are processed and screened in full compliance with MIL-PRF-38535. * MIL-PRF-38535 Class V Compliant * User Programmable For Closed-Loop Gains of +1, -1 or +2 Without Use of External Resistors * Standard Operational Amplifier Pinout A unique feature of the pinout allows the user to select a voltage gain of +1, -1, or +2, without the use of any external components. Gain selection is accomplished via connections to the inputs, as described in the "Application Information" section. The result is a more flexible product, fewer part types in inventory, and more efficient use of board space. * Low Supply Current. . . . . . . . . . . 5.9mA/Op Amp (Typ) * Excellent Gain Accuracy . . . . . . . . . . . . . . 0.99V/V (Typ) * Wide -3dB Bandwidth . . . . . . . . . . . . . . . 340MHz (Typ) * Fast Slew Rate . . . . . . . . . . . . . . . . . . . . 1155V/s (Typ) Compatibility with existing op amp pinouts provides flexibility to upgrade low gain amplifiers, while decreasing component count. Unlike most buffers, the standard pinout provides an upgrade path should a higher closed loop gain be needed at a future date. * High Input Impedance . . . . . . . . . . . . . . . . . . 1M (Typ) * Excellent Gain Flatness (to 50MHz) . . . . 0.02dB (Typ) * Fast Overdrive Recovery. . . . . . . . . . . . . . . <10ns (Typ) Detailed Electrical Specifications are contained in SMD #5962F9683401VCA, available on the Harris Web site or AnswerFAX Systems (Document #968340) * Total Gamma Dose. . . . . . . . . . . . . . . . . . 300K RAD(Si) * Latch Up . . . . . . . . . . . . . . . . . . . . .None (DI Technolgy) A Cross Reference Table is available on the Harris Website for conversion of Harris Part Numbers to SMDs. The address is (http://www.semi.harris.com/datasheets/smd/smd_xref.ht ml). SMD numbers must be used to order Radiation Hardened Products. Applications * Flash A/D Driver * Video Switching and Routing Ordering Information * Pulse and Video Amplifiers PART NUMBER TEMP. RANGE (oC) * RF/IF Signal Processing 5962F9683401VCA -55 to 125 14 Ld CERDIP GDIP1-T14 * Imaging Systems HFA1145IP (Samples) -40 to 85 14 Ld PDIP * Wideband Amplifiers HA5025EVAL PACKAGE PKG. NO. E14.3 Evaluation Board Pinout HS-1412RH (CERDIP) MIL-STD-1835 GDIP1-T14 TOP VIEW OUT1 1 14 OUT4 -IN1 2 13 -IN4 +IN1 3 12 +IN4 V+ 4 11 V- +IN2 5 10 +IN3 -IN2 6 9 -IN3 8 OUT3 OUT2 7 CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures. Copyright (c) Harris Corporation 1996 1 File Number 4230 HS-1412RH Application Information HS-1412RH Advantages Unity Gain Considerations The HS-1412RH features a novel design which allows the user to select from three closed loop gains, without any external components. The result is a more flexible product, fewer part types in inventory, and more efficient use of board space. Implementing a quad, gain of 2, cable driver with this IC eliminates the eight gain setting resistors, which frees up board space for termination resistors. Unity gain selection is accomplished by floating the -Input of the HS-1412RH. Anything that tends to short the -Input to GND, such as stray capacitance at high frequencies, will cause the amplifier gain to increase toward a gain of +2. The result is excessive high frequency peaking, and possible instability. Even the minimal amount of capacitance associated with attaching the -Input lead to the PCB results in approximately 6dB of gain peaking. At a minimum this requires due care to ensure the minimum capacitance at the -Input connection. Like most newer high performance amplifiers, the HS-1412RH is a current feedback amplifier (CFA). CFAs offer high bandwidth and slew rate at low supply currents, but can be difficult to use because of their sensitivity to feedback capacitance and parasitics on the inverting input (summing node). The HS1412RH eliminates these concerns by bringing the gain setting resistors on-chip. This yields the optimum placement and value of the feedback resistor, while minimizing feedback and summing node parasitics. Because there is no access to the summing node, the PCB parasitics do not impact performance at gains of +2 or -1 (see "Unity Gain Considerations" for discussion of parasitic impact on unity gain performance). Closed Loop Gain Selection Table 1 lists five alternate methods for configuring the HS1412RH as a unity gain buffer, and the corresponding performance. The implementations vary in complexity and involve performance trade-offs. The easiest approach to implement is simply shorting the two input pins together, and applying the input signal to this common node. The amplifier bandwidth decreases from 550MHz to 370MHz, but excellent gain flatness is the benefit. A drawback to this approach is that the amplifier input noise voltage and input offset voltage terms see a gain of +2, resulting in higher noise and output offset voltages. Alternately, a 100pF capacitor between the inputs shorts them only at high frequencies, which prevents the increased output offset voltage but delivers less gain flatness. This "buffer" operates in closed loop gains of -1, +1, or +2, with gain selection accomplished via connections to the inputs. Applying the input signal to +IN and floating -IN selects a gain of +1 (see next section for layout caveats), while grounding -IN selects a gain of +2. A gain of -1 is obtained by applying the input signal to -IN with +IN grounded through a 50 resistor. Another straightforward approach is to add a 620 resistor in series with the amplifier's positive input. This resistor and the HS-1412RH input capacitance form a low pass filter which rolls off the signal bandwidth before gain peaking occurs. This configuration was employed to obtain the data sheet AC and transient parameters for a gain of +1. The table below summarizes these connections: Pulse Overshoot The HS-1412RH's closed loop gain implementation provides better gain accuracy, lower offset and output impedance, and better distortion compared with open loop buffers. The HS-1412RH utilizes a quasi-complementary output stage to achieve high output current while minimizing quiescent supply current. In this approach, a composite device replaces the traditional PNP pulldown transistor. The composite device switches modes after crossing 0V, resulting in added distortion for signals swinging below ground, and an increased overshoot on the negative portion of the output waveform (see Figure 5, Figure 7, and Figure 9). This overshoot isn't present for small bipolar signals (see Figure 4, Figure 6, and Figure 8) or large positive signals. Figure 28 through Figure 31 illustrate the amplifier's overshoot dependency on input transition time, and signal polarity. CONNECTIONS GAIN (ACL) +INPUT -INPUT -1 50 to GND Input +1 Input NC (Floating) +2 Input GND TABLE 1. UNITY GAIN PERFORMANCE FOR VARIOUS IMPLEMENTATIONS PEAKING (dB) BW (MHz) SR (V/s) 0.1dB GAIN FLATNESS (MHz) Remove -IN Pin 5.0 550 1300 18 +RS = 620 1.0 230 1000 25 +RS = 620 and Remove -IN Pin 0.7 225 1000 28 Short +IN to -IN (e.g., Pins 2 and 3) 0.1 370 500 170 100pF Capacitor Between +IN and -IN 0.3 380 550 130 APPROACH 2 HS-1412RH PC Board Layout Evaluation Board This amplifier's frequency response depends greatly on the care taken in designing the PC board (PCB). The use of low inductance components such as chip resistors and chip capacitors is strongly recommended, while a solid ground plane is a must! The performance of the HS-1412RH may be evaluated using the HA5025 Evaluation Board, slightly modified as follows: 1. Remove the four feedback resistors, and leave the connections open. 2. a. For AV = +1 evaluation, remove the gain setting resistors (R1), and leave pins 2, 6, 9, and 13 floating. b. For AV = +2, replace the gain setting resistors (R1) with 0 resistors to GND. Attention should be given to decoupling the power supplies. A large value (10F) tantalum in parallel with a small value (0.1F) chip capacitor works well in most cases. The modified schematic for amplifier 1, and the board layout are shown in Figures 2 and 3. Terminated microstrip signal lines are recommended at the input and output of the device. Capacitance directly on the output must be minimized, or isolated as discussed in the next section. To order evaluation boards (part number HA5025EVAL), please contact your local sales office. 50 An example of a good high frequency layout is the Evaluation Board shown in Figure 3. OUT R1 (NOTE) Driving Capacitive Loads IN 14 2 13 3 50 Capacitive loads, such as an A/D input, or an improperly terminated transmission line will degrade the amplifier's phase margin resulting in frequency response peaking and possible oscillations. In most cases, the oscillation can be avoided by placing a resistor (RS) in series with the output prior to the capacitance. 1 4 + NOTE: R1 = (AV = +1) or 0 (AV = +2) 12 11 5 10 0.1F 6 9 7 8 -5V 0.1F +5V 10F GND GND FIGURE 2. MODIFIED EVALUATION BOARD SCHEMATIC Figure 1 details starting points for the selection of this resistor. The points on the curve indicate the RS and CL combinations for the optimum bandwidth, stability, and settling time, but experimental fine tuning is recommended. Picking a point above or to the right of the curve yields an overdamped response, while points below or left of the curve indicate areas of underdamped performance. RS and CL form a low pass network at the output, thus limiting system bandwidth well below the amplifier bandwidth of 350MHz. By decreasing RS as CL increases (as illustrated in the curves), the maximum bandwidth is obtained without sacrificing stability. In spite of this, bandwidth decreases as the load capacitance increases. For example, at AV = +2, RS = 22, CL = 100pF, the overall bandwidth is 125MHz, and bandwidth drops to 100MHz at RS = 12, CL = 220pF. SERIES OUTPUT RESISTANCE () 50 FIGURE 3A. TOP LAYOUT 40 30 20 AV = +1 AV = +2 10 0 0 50 100 150 200 250 300 350 10F 400 LOAD CAPACITANCE (pF) FIGURE 1. RECOMMENDED SERIES RESISTOR vs LOAD CAPACITANCE FIGURE 3B. BOTTOM LAYOUT FIGURE 3. EVALUATION BOARD LAYOUT 3 HS-1412RH Typical Performance Curves VSUPPLY = 5V, TA = 25oC, RL = 100, Unless Otherwise Specified 2.0 200 AV = +2 150 1.5 100 1.0 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (mV) AV = +2 50 0 -50 -100 -150 0.5 0 -0.5 -1.0 -1.5 -200 -2.0 TIME (5ns/DIV.) TIME (5ns/DIV.) FIGURE 4. SMALL SIGNAL PULSE RESPONSE FIGURE 5. LARGE SIGNAL PULSE RESPONSE 2.0 200 1.5 100 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (mV) 150 AV = +1 50 0 -50 -100 -150 AV = +1 1.0 0.5 0 -0.5 -1.0 -1.5 -200 -2.0 TIME (5ns/DIV.) TIME (5ns/DIV.) FIGURE 6. SMALL SIGNAL PULSE RESPONSE FIGURE 7. LARGE SIGNAL PULSE RESPONSE 2.0 200 AV = -1 150 1.5 100 1.0 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (mV) AV = -1 50 0 -50 -100 -150 0.5 0 -0.5 -1.0 -1.5 -200 -2.0 TIME (5ns/DIV.) TIME (5ns/DIV.) FIGURE 8. SMALL SIGNAL PULSE RESPONSE FIGURE 9. LARGE SIGNAL PULSE RESPONSE 4 HS-1412RH 9 3 AV = +2 GAIN AV = -1 AV = +1 AV = +2 PHASE 0 90 0.3 1 AV = -1 180 AV = +1 270 10 FREQUENCY (MHz) 100 0.3 500 GAIN (dB) 0 GAIN -3 RL = 1k RL = 100 RL = 50 0 90 10 FREQUENCY (MHz) 180 270 100 RL = 1k RL =100 RL = 50 180 90 500 0.3 1 10 FREQUENCY (MHz) 100 0 -90 500 FIGURE 13. FREQUENCY RESPONSE FOR VARIOUS LOAD RESISTORS AV = +1 GAIN GAIN (dB) 3 1VP-P 2.5VP-P 4VP-P 3 0 0 PHASE 90 1VP-P 2.5VP-P 4VP-P 1 10 FREQUENCY (MHz) 180 270 100 0 GAIN -3 1VP-P 2.5VP-P 4VP-P -6 360 500 PHASE (DEGREES) GAIN (dB) 500 GAIN -3 RL = 1k RL = 100 RL = 50 AV = +2 0.3 100 PHASE FIGURE 12. FREQUENCY RESPONSE FOR VARIOUS LOAD RESISTORS 6 10 FREQUENCY (MHz) 270 AV = -1, VOUT = 200mVP-P -6 PHASE 1 0 PHASE (DEGREES) GAIN (dB) 3 0.3 1 180 FIGURE 11. FREQUENCY RESPONSE FOR VARIOUS LOAD RESISTORS AV = +1, VOUT = 200mVP-P RL = 1k RL = 100 RL = 50 90 RL = 1k RL = 100 RL = 50 FIGURE 10. FREQUENCY RESPONSE -6 0 PHASE PHASE (DEGREES) -6 9 RL = 1k RL = 100 RL = 50 0 -3 3 GAIN 3 0 PHASE 90 180 1VP-P 2.5VP-P 4VP-P 0.3 FIGURE 14. FREQUENCY RESPONSE FOR VARIOUS OUTPUT VOLTAGES 1 10 FREQUENCY (MHz) 270 100 360 500 PHASE (DEGREES) 0 6 AV = +2, VOUT = 200mVP-P PHASE (DEGREES) VOUT = 200mVP-P GAIN (dB) 6 VSUPPLY = 5V, TA = 25oC, RL = 100, Unless Otherwise Specified (Continued) PHASE (DEGREES) NORMALIZED GAIN (dB) Typical Performance Curves FIGURE 15. FREQUENCY RESPONSE FOR VARIOUS OUTPUT VOLTAGES 5 HS-1412RH Typical Performance Curves 6 NORMALIZED GAIN (dB) 0 AV = -1 GAIN -3 1VP-P 2.5VP-P 4VP-P -6 180 1VP-P PHASE 90 4VP-P 2.5VP-P 0 -90 0.3 1 10 FREQUENCY (MHz) 100 PHASE (DEGREES) GAIN (dB) 3 VSUPPLY = 5V, TA = 25oC, RL = 100, Unless Otherwise Specified (Continued) VOUT = 5VP-P 3 0 -3 AV = +2 AV = +1 AV = -1 -6 -9 -12 -15 -18 -21 0.3 500 1 FIGURE 16. FREQUENCY RESPONSE FOR VARIOUS OUTPUT VOLTAGES 10 FREQUENCY (MHz) 100 500 FIGURE 17. FULL POWER BANDWIDTH 0.5 450 VOUT = 200mVP-P 0.4 NORMALIZED GAIN (dB) AV = +2 350 AV = -1 300 250 AV = +1 0.3 0.2 AV = +1 0.1 AV = +2 0 -0.1 -0.2 AV = -1 -0.3 -0.4 200 -50 -25 0 25 50 75 100 -0.5 125 TEMPERATURE (oC) 1 FIGURE 18. -3dB BANDWIDTH vs TEMPERATURE -40 0 -45 -10 -50 -20 CROSSTALK (dB) AV = +2 AV = -1 AV = +1 -60 -65 -70 -75 -50 -60 -90 100 500 0.3 FIGURE 20. REVERSE ISOLATION (S12) RL = 100 RL = -70 -85 10 FREQUENCY (MHz) 200 -40 -80 1 100 -30 -80 -90 0.3 10 FREQUENCY (MHz) FIGURE 19. GAIN FLATNESS -55 GAIN (dB) BANDWIDTH (MHz) 400 1 10 FREQUENCY (MHz) FIGURE 21. ALL HOSTILE CROSSTALK 6 100 HS-1412RH Typical Performance Curves VSUPPLY = 5V, TA = 25oC, RL = 100, Unless Otherwise Specified (Continued) -40 -40 AV = +2 AV = +2 -45 20MHz -50 -50 DISTORTION (dBc) DISTORTION (dBc) -45 10MHz -55 -60 -65 -70 -60 10MHz -65 -70 -75 -75 -80 -5 20MHz -55 -80 -2 1 4 7 10 13 -5 -2 OUTPUT POWER (dBm) 1 4 7 10 13 OUTPUT POWER (dBm) FIGURE 22. 2nd HARMONIC DISTORTION vs POUT FIGURE 23. 3rd HARMONIC DISTORTION vs POUT -40 -40 AV = +1 AV = +1 -45 -45 20MHz -50 DISTORTION (dBc) DISTORTION (dBc) -50 -55 10MHz -60 -65 20MHz -55 -60 -70 -70 -75 -75 -80 -5 -80 -2 1 4 7 OUTPUT POWER (dBm) 10 13 -5 FIGURE 24. 2nd HARMONIC DISTORTION vs POUT -2 1 4 7 OUTPUT POWER (dBm) 10 13 FIGURE 25. 3rd HARMONIC DISTORTION vs POUT -40 -40 AV = -1 AV = -1 20MHz -45 -45 -50 DISTORTION (dBc) DISTORTION (dBc) 10MHz -65 10MHz -55 -60 -65 -70 -75 -50 20MHz -55 -60 10MHz -65 -70 -75 -80 -5 -80 -2 1 4 7 10 13 -5 OUTPUT POWER (dBm) -2 1 4 7 10 OUTPUT POWER (dBm) FIGURE 26. 2nd HARMONIC DISTORTION vs POUT FIGURE 27. 3rd HARMONIC DISTORTION vs POUT 7 13 HS-1412RH Typical Performance Curves VSUPPLY = 5V, TA = 25oC, RL = 100, Unless Otherwise Specified (Continued) 20 20 VOUT = +1V VOUT = +0.5V 15 OVERSHOOT (%) OVERSHOOT (%) 15 10 AV = +1 10 AV = +1 5 5 0 100 500 AV = +2 AV = +2 AV = -1 900 1300 AV = -1 1700 0 100 2100 500 INPUT TRANSITION TIME (ps) 900 FIGURE 28. OVERSHOOT vs TRANSITION TIME 1700 2100 FIGURE 29. OVERSHOOT vs TRANSITION TIME 20 20 VOUT = 1VP-P VOUT = 0.5VP-P OVERSHOOT (%) AV = +1 10 AV = +2 AV = +1 AV = +2 15 15 OVERSHOOT (%) 1300 INPUT TRANSITION TIME (ps) AV = -1 10 5 5 AV = -1 0 100 500 900 1300 1700 0 100 2100 500 900 1300 1700 2100 INPUT TRANSITION TIME (ps) INPUT TRANSITION TIME (ps) FIGURE 31. OVERSHOOT vs TRANSITION TIME FIGURE 30. OVERSHOOT vs TRANSITION TIME 0.02 AV = -1 ERROR (%) -0.01 0.2 AV = +2 0 SETTLING ERROR (%) 0.01 AV = +1 -0.02 -0.03 AV = +2 -0.04 -0.05 -0.06 -1.5 0.1 0.05 0 -0.05 -0.1 -0.2 -1.0 -0.5 0 0.5 1.0 1.5 10 INPUT VOLTAGE (V) FIGURE 32. INTEGRAL LINEARITY ERROR 20 30 40 50 TIME (ns) 60 70 FIGURE 33. SETTLING RESPONSE 8 80 90 HS-1412RH VSUPPLY = 5V, TA = 25oC, RL = 100, Unless Otherwise Specified (Continued) 3.6 6.5 3.5 6.4 3.4 OUTPUT VOLTAGE (V) 6.6 6.3 6.2 6.1 6.0 5.9 5.8 +VOUT (RL= 100) 3.3 3.2 |-VOUT| (RL= 50) 3.1 +VOUT (RL= 50) 3.0 2.9 2.7 5.6 2.6 5 5.5 6 SUPPLY VOLTAGE (V) 6.5 -50 7 -25 0 50 20 40 16 30 12 8 20 INI 4 ENI 0 0.1 50 75 100 FIGURE 35. OUTPUT VOLTAGE vs TEMPERATURE FIGURE 34. SUPPLY CURRENT vs SUPPLY VOLTAGE 10 25 TEMPERATURE (oC) 1 10 FREQUENCY (kHz) 0 100 FIGURE 36. INPUT NOISE CHARACTERISTICS 9 NOISE CURRENT (pA/Hz) 5.5 4.5 |-VOUT| (RL= 100) AV = -1 2.8 5.7 NOISE VOLTAGE (nV/Hz) SUPPLY CURRENT (mA/AMPLIFIER) Typical Performance Curves 125 HS-1412RH Burn-In Circuit HS-1412RH CERDIP 1 14 2 13 3 12 4 11 R1 D3 V+ D1 C1 R1 R1 D4 VR1 5 10 6 9 7 8 C2 D2 NOTES: 1. R1 = 1k, 5%, 1/4W [Per Socket]. 5. (-V) + (+V) = 11V 1.0V. 2. C1 = C2 = 0.01F [Per Socket] or 0.1F (Per Row) Minimum. 6. 20mA < (ICC, IEE) < 32mA. 3. D1 = D2 = 1N4002 or Equivalent [Per Board]. 7. -50mV < VOUT < +50mV. 4. D3 = D4 = 1N4002 or Equivalent [Per Socket]. Irradiation Circuit HS-1412RH CERDIP 1 14 2 13 3 12 4 11 R1 V+ R1 R1 C1 VR1 5 10 6 9 7 8 NOTES: 1. R1 = 1k 5% 2. C1 = 0.1F 3. V+ = +5.0V 0.5V 4. V- = -5.0V 0.5V 10 C1 HS-1412RH Die Characteristics DIE DIMENSIONS: 79 mils x 118 mils x 19 mils (2000m x 3000m x 483m) SUBSTRATE POTENTIAL (Powered Up) Floating (Recommend Connection to V-) PASSIVATION: Type: Nitride Thickness: 4kA 0.5kA METALLIZATION: Type: Metal 1: AICu(2%)/TiW Thickness: Metal 1: 8kA 0.4kA Type: Metal 2: AICu(2%) Thickness: Thickness: Metal 2: 16kA 0.8kA TRANSISTOR COUNT: 320 Metallization Mask Layout HS-1412RH -IN1 OUT1 OUT4 -IN4 +IN1 +IN4 V+ V- +IN2 +IN3 -IN2 OUT2 V- 11 OUT3 -IN3