HS-1212RH S E M I C O N D U C T O R Radiation Hardened, Dual, High Speed Low Power, Video Closed Loop Buffer August 1996 Features Description * Electrically Screened to SMD# 5962F9683101VPA The HS-1212RH is a dual closed loop buffer featuring user programmable gain and high speed performance. Manufactured on Harris' proprietary complementary bipolar UHF-1 (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 * Low Supply Current. . . . . . . . . . 5.9mA/Op Amp (Typ) 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. * Excellent Gain Accuracy . . . . . . . . . . . . . . 0.99V/V (Typ) * Wide -3dB Bandwidth . . . . . . . . . . . . . . . 340MHz (Typ) * Fast Slew Rate . . . . . . . . . . . . . . . . . . . . 1155V/s (Typ) * High Input Impedance . . . . . . . . . . . . . . . . . . 1M (Typ) * Excellent Gain Flatness (to 50MHz) . . . . 0.02dB (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. * Fast Overdrive Recovery. . . . . . . . . . . . . . . <10ns (Typ) * Total Gamma Dose. . . . . . . . . . . . . . . . . . 300K RAD(Si) * Latch Up . . . . . . . . . . . . . . . . . . . None (DI Technology) Detailed Electrical Specifications are contained in SMD #5962F9683101VPA, available on the Harris Web site or AnswerFAX Systems (Document #968310). Applications * Flash A/D Driver 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. html). SMD numbers must be used to order Radiation Hardened Products. * Video Switching and Routing * Pulse and Video Amplifiers * Wideband Amplifiers Ordering Information * RF/IF Signal Processing * Imaging Systems PART NUMBER TEMP. 5962F96830101VPA -55 to 125 8 Ld CERDIP GDIP1-T8 HFA1212IP (Samples) -40 TO 85 8 Ld PDIP E8.3 HA5023EVAL Pinout PACKAGE PKG. Evaluation Board HS-1212RH CERDIP MIL-STD-1835 GDIP1-T8 TOP VIEW OUT1 1 8 V+ 7 OUT2 6 -IN2 5 +IN2 -+ -IN1 2 +IN1 3 V- 4 +- CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures. Copyright (c) Harris Corporation 1996 1 File Number 4228 HS-1212RH Application Information 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. HS-1212RH Advantages The HS-1212RH 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 dual, gain of 2, cable driver with this IC eliminates the four gain setting resistors, which frees up board space for termination resistors. Table 1 lists five alternate methods for configuring the HS1212RH 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 430MHz to 280MHz, 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. Like most newer high performance amplifiers, the HS1212RH 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 HS-1212RH 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). Another straightforward approach is to add a 620 resistor in series with the amplifier's positive input. This resistor and the HS-1212RH 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 HS-1212RH's closed loop gain implementation provides better gain accuracy, lower offset and output impedance, and better distortion compared with open loop buffers. Closed Loop Gain Selection Pulse Overshoot 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. The HS-1212RH 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 6, Figure 9, and Figure 12). This overshoot isn't present for small bipolar signals (see Figure 4, Figure 7, and Figure 10) or large positive signals (see Figure 5, Figure 8 and Figure 11). The table below summarizes these connections: CONNECTIONS GAIN (ACL) +INPUT -INPUT -1 50 to GND Input +1 Input NC (Floating) +2 Input GND PC Board Layout 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! Unity Gain Considerations Unity gain selection is accomplished by floating the -Input of the HS-1212RH. 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 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. TABLE 1. UNITY GAIN PERFORMANCE FOR VARIOUS IMPLEMENTATIONS PEAKING (dB) BW (MHz) 0.1dB GAIN FLATNESS (MHz) 4.5 430 21 0 220 27 +RS = 620 and Remove -IN Pin 0.5 215 15 Short +IN to -IN (e.g., Pins 2 and 3) 0.6 280 70 100pF Capacitor Between +IN and -IN 0.7 290 40 APPROACH Remove -IN Pin +RS = 620 2 HS-1212RH 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 HA5023EVAL), please contact your local sales office. An example of a good high frequency layout is the Evaluation Board shown in Figure 3. Driving Capacitive Loads 50 OUT 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 R1 (NOTE) IN 3 50 4 -5V 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. 10F 2 0.1F +5V 8 - + 0.1F 7 6 5 GND GND NOTE: R1 = (AV = +1) or 0 (AV = +2) FIGURE 2. MODIFIED EVALUATION BOARD SCHEMATIC 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. SERIES OUTPUT RESISTANCE () 50 40 30 FIGURE 3A. TOP LAYOUT 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 Evaluation Board The performance of the HS-1212RH may be evaluated using the HA5023 Evaluation Board, slightly modified as follows: 1. Remove the two feedback resistors, and leave the connections open. FIGURE 3B. BOTTOM LAYOUT 2. a. For AV = +1 evaluation, remove the gain setting resistors (R1), and leave pins 2 and 6 floating. b. For AV = +2, replace the gain setting resistors (R1) with 0 resistors to GND. 3 FIGURE 3. EVALUATION BOARD LAYOUT HS-1212RH Typical Performance Curves 2.0 AV = +2 150 1.5 100 1.0 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (mV) 200 VSUPPLY = 5V, TA = 25oC, RL = 100, Unless Otherwise Specified 50 0 -50 -100 -150 AV = +2 0.5 0 -0.5 -1.0 -1.5 -200 -2.0 TIME (5ns/DIV.) TIME (5ns/DIV.) FIGURE 4. SMALL SIGNAL PULSE RESPONSE 200 AV = +2 1.5 150 1.0 100 OUTPUT VOLTAGE (mV) OUTPUT VOLTAGE (V) 2.0 FIGURE 5. LARGE SIGNAL POSITIVE PULSE RESPONSE 0.5 0 -0.5 -1.0 AV = +1 50 0 -50 -100 -150 -1.5 -200 -2.0 TIME (5ns/DIV.) TIME (5ns/DIV.) FIGURE 6. LARGE SIGNAL BIPOLAR PULSE RESPONSE 2.0 AV = +1 1.5 1.5 1.0 1.0 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 2.0 FIGURE 7. SMALL SIGNAL PULSE RESPONSE 0.5 0 -0.5 -1.0 -1.5 0.5 0 -0.5 -1.0 -1.5 -2.0 -2.0 TIME (5ns/DIV.) FIGURE 8. AV = +1 TIME (5ns/DIV.) LARGE SIGNAL POSITIVE PULSE RESPONSE FIGURE 9. LARGE SIGNAL BIPOLAR PULSE RESPONSE 4 HS-1212RH Typical Performance Curves (Continued) VSUPPLY = 5V, TA = 25oC, RL = 100, Unless Otherwise Specified 2.0 200 150 1.5 100 1.0 OUTPUT VOLTAGE (V) 50 0 -50 -100 0.5 0 -0.5 -1.0 -1.5 -150 -2.0 -200 TIME (5ns/DIV.) TIME (5ns/DIV.) FIGURE 10. SMALL SIGNAL PULSE RESPONSE FIGURE 11. NORMALIZED GAIN (dB) 2.0 AV = -1 1.5 1.0 OUTPUT VOLTAGE (V) AV = -1 0.5 0 LARGE SIGNAL POSITIVE PULSE RESPONSE 6 3 AV = +2 GAIN 0 -3 AV = +1 -6 AV = -1 PHASE -9 0 -90 -0.5 -1.0 VOUT = 200mVP-P +RS = 620 (+1) +RS = 0 (-1, +2) -1.5 1 -2.0 TIME (5ns/DIV.) 0.7 3 0.6 0 0.5 NORMALIZED GAIN (dB) NORMALIZED GAIN (dB) 6 -3 -6 AV = -1 AV = +2 AV = +1 VOUT = 4VP-P (+1) VOUT = 5VP-P (-1, +2) +RS = 620 (+1) 10 FREQUENCY (MHz) -360 600 VOUT = 200mVP-P +RS = 620 (+1) +RS = 0 (-1, +2) 0.3 AV = +2 0.2 0.1 0 -0.1 AV = +1 -0.2 100 10 100 FREQUENCY (MHz) -270 0.4 -0.3 1 AV = +2 -180 FIGURE 13. FREQUENCY RESPONSE FIGURE 12. LARGE SIGNAL BIPOLAR PULSE RESPONSE -9 AV = +1 NORMALIZED PHASE (DEGREES) OUTPUT VOLTAGE (mV) AV = -1 300 FIGURE 14. FULL POWER BANDWIDTH 1 10 FREQUENCY (MHz) FIGURE 15. GAIN FLATNESS 5 AV = -1 100 HS-1212RH Typical Performance Curves -10 -10 -20 -20 -30 -30 CROSSTALK (dB) AV = -1 -40 GAIN (dB) (Continued) VSUPPLY = 5V, TA = 25oC, RL = 100, Unless Otherwise Specified -50 AV = +1 -60 -70 -80 RL = -40 -50 RL = 100 -60 -70 -80 -90 -90 AV = +2 -100 -110 0.3 1 -100 10 FREQUENCY (MHz) -110 0.3 100 FIGURE 16. REVERSE ISOLATION 1 10 FREQUENCY (MHz) 100 500 FIGURE 17. ALL HOSTILE CROSSTALK -40 -40 -45 -45 DISTORTION (dBc) 20MHz DISTORTION (dBc) AV = +2 -50 -55 10MHz -60 -50 20MHz -55 -60 10MHz -65 -65 -70 -10 -5 0 5 10 -70 -10 15 OUTPUT POWER (dBm) FIGURE 18. 2nd HARMONIC DISTORTION vs POUT 0 5 OUTPUT POWER (dBm) 10 15 FIGURE 19. 3rd HARMONIC DISTORTION vs POUT 20 20 16 16 12 12 NOISE VOLTAGE (nV/Hz) 0.05 0 -0.05 -0.10 8 8 ENI 4 4 INI 13 33 53 73 93 113 TIME (ns) 133 153 0 0.1 173 FIGURE 20. SETTLING RESPONSE 1 10 FREQUENCY (kHz) 0 100 FIGURE 21. INPUT NOISE CHARACTERISTICS 6 NOISE CURRENT (pA/Hz) AV = +1 0.10 SETTLING ERROR (%) -5 HS-1212RH Typical Performance Curves (Continued) VSUPPLY = 5V, TA = 25oC, RL = 100, Unless Otherwise Specified 3.6 OUTPUT VOLTAGE (V) 3.5 |-VOUT| (RL= 100) AV = -1 +VOUT (RL= 100) 3.4 3.3 3.2 |-VOUT| (RL= 50) 3.1 +VOUT (RL= 50) 3.0 2.9 2.8 2.7 2.6 -50 -25 0 25 50 75 100 TEMPERATURE (oC) FIGURE 22. OUTPUT VOLTAGE vs TEMPERATURE 7 125 HS-1212RH Burn-In Circuit HS-1212RH CERDIP D3 1 8 V+ -+ 2 3 D4 R1 7 +- 4 VD2 C1 D1 6 5 C2 R1 NOTES: 1. R1 = 1k, 5% (Per Socket). 2. C1 = C2 = 0.01F (Per Socket) or 0.1F (Per Row) Minimum. 3. D1 = D2 = 1N4002 or Equivalent (Per Board). 4. D3 = D4 = 1N4002 or Equivalent (Per Socket). 5. |(-V)| + |(+V)| = 11V 1.0V. 6. 10mA. < | ICC, IEE | < 16 mA. 7. -50mV < VOUT < +50mV. Irradiation Circuit HS-1212RH CERDIP 1 V+ 8 -+ 2 R1 3 C1 7 +- 6 R1 4 V- 5 C1 NOTES: 1. R1 = 1k, 5% 2. C1 = 0.01F 3. V+ = +5.0V 0.5V 4. V- = -5.0V 0.5V 8 HS-1212RH Die Characteristics DIE DIMENSIONS: 69 mils x 92 mils x 19 mils 1750m x 2330m x 483m METALLIZATION: Type: Metal 1: AICu(2%)/TiW Thickness: Metal 1: 8kA 0.4kA Type: Metal 2: AICu(2%) Thickness: Metal 2: 16kA 0.8kA PASSIVATION: Type: Nitride Thickness: 4kA 0.5kA TRANSISTOR COUNT: 180 SUBSTRATE POTENTIAL (Powered Up): Floating (Recommend Connection to V-) Metallization Mask Layout HS-1212RH OUT1 -IN1 NC V+ NC OUT2 +IN1 NC NC -IN2 NC V- +IN2 NC Sales Office Headquarters For general information regarding Harris Semiconductor and its products, call 1-800-4-HARRIS NORTH AMERICA Harris Semiconductor P. O. Box 883, Mail Stop 53-210 Melbourne, FL 32902 TEL: 1-800-442-7747 (407) 729-4984 FAX: (407) 729-5321 EUROPE Harris Semiconductor Mercure Center 100, Rue de la Fusee 1130 Brussels, Belgium TEL: (32) 2.724.2111 FAX: (32) 2.724.22.05 S E M I C O N D U C TO R 9 ASIA Harris Semiconductor PTE Ltd. 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