Surface Mount RF Schottky Diodes in SOT-363 (SC-70, 6 Lead) Technical Data HSMS-280L / M / N / P/ R HSMS-281L HSMS-282L / M / N / P/ R Features • Surface Mount SOT-363 Package • Low Turn-On Voltage (As Low as 0.34 V at 1 mA) • Low FIT (Failure in Time) Rate* • Six-sigma Quality Level • Single and Dual Versions • Tape and Reel Options Available * For more information see the Surface Mount Schottky Reliability Data Sheet. Package Lead Code Identification (Top View) Description/Applications COMMON UNCONNECTED CATHODE QUAD TRIO 6 5 1 2 4 6 5 3 1 2 4 3 L M COMMON ANODE QUAD BRIDGE QUAD 6 5 1 2 6 N 4 6 5 3 1 2 4 P 3 Pin Connections and Package Marking RING QUAD 5 These Schottky diodes are specifically designed for analog and digital applications requiring devices in SOT-363 surface mount packages. This series offers a wide range of specifications and package configurations to give the designer wide flexibility. Typical applications of these Schottky diodes are mixing, detecting, switching, sampling, clamping, and wave shaping. 4 2 R 3 2 Absolute Maximum Ratings, TC= 25ºC Symbol Parameter If PIV TJ TSTG θ jc 3 Unit Absolute Maximum Forward Current (1µs Pulse) Amp Peak Inverse Voltage V Junction Temperature °C Storage Temperature °C Thermal Resistance [2] °C/W 1 Same as VBR 150 -65 to 150 140 Notes: 1. Operation in excess of any one of these conditions may result in permanent damage to the device. 2. TC = +25°C, where TC is defined to be the temperature at the package pins where contact is made to the circuit board. GU 1 1 6 5 4 [1] Notes: 1. Package marking provides orientation and identification. 2. See “Electrical Specifications” for appropriate package marking. 2 Electrical Specifications, TC = +25°C, Single Diode [1] Minimum Maximum Maximum Maximum Typical Breakdown Forward Forward Reverse Maximum Dynamic Voltage Voltage Voltage Leakage Capacitance Resistance VBR (V) VF (mV) VF (V) @ IR (nA) @ CT (pF) RD (Ω) IF (mA) VR (V) Part Package Number Marking Lead HSMS- Code[2] Code Configuration 280L AL 280M H 280N N 280P AP 280R O 281L BL 282L CL 282M HH 282N NN 282P CP 282R OO Test Conditions L M N P R L L M N P R Unconnected Trio Common Cathode Quad Common Anode Quad Bridge Quad Ring Quad Unconnected Trio Unconnected Trio Common Cathode Quad Common Anode Quad Bridge Quad Ring Quad 70 400 1.0 15 200 50 2.0 35 20 15 400 340 1.0 35 0.7 30 200 15 100 1 1.2 1.0 15 12 VF = 0 V IF = 5 mA IR = 10 µA IF = 1 mA[3] f = 1 MHz [4] Notes: 1. Effective Carrier Lifetime (τ) for all these diodes is 100 ps maximum measured with Krakauer method at 5 mA, except HSMS-282X which is measured at 20 mA. 2. Package marking code is laser marked. 3. ∆VF for diodes in trios and quads is 15.0 mV maximum at 1.0 mA. 4. ∆CTO for diodes in trios and quads is 0.2 pF maximum. Typical Performance, TC = 25°C (unless otherwise noted), Single Diode 10 1 TA = +125°C TA = +75°C TA = +25°C TA = –25°C 0.1 0.01 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 VF – FORWARD VOLTAGE (V) Figure 1. Forward Current vs. Forward Voltage at Temperatures— HSMS-280A Series. 100 10 1 TA = +125°C TA = +75°C TA = +25°C TA = –25°C 0.1 0.01 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 VF – FORWARD VOLTAGE (V) Figure 2. Forward Current vs. Forward Voltage at Temperatures— HSMS-281L. I F – FORWARD CURRENT (mA) 100 I F – FORWARD CURRENT (mA) I F – FORWARD CURRENT (mA) 100 TA = +125°C TA = +75°C TA = +25°C TA = –25°C 10 1 0.1 0.01 0 0.10 0.20 0.30 0.40 0.50 VF – FORWARD VOLTAGE (V) Figure 3. Forward Current vs. Forward Voltage at Temperatures— HSMS-282A Series. 3 Typical Performance, TC = 25°C (unless otherwise noted), Single Diode, continued 10,000 10,000 10,000 1000 100 TA = +125°C TA = +75°C TA = +25°C 10 1 0 10 20 30 40 1000 100 TA = +125°C TA = +75°C TA = +25°C 10 1 50 0 VR – REVERSE VOLTAGE (V) 10 10 HSMS-2800 SERIES HSMS-2810 SERIES HSMS-2820 SERIES 10 0.8 0.6 0.4 0.2 0 4 6 1 0.5 8 VR – REVERSE VOLTAGE (V) Figure 10. Total Capacitance vs. Reverse Voltage—HSMS-282A Series. 10 15 Figure 6. Reverse Current vs. Reverse Voltage at Temperatures— HSMS-282A Series. 1 0.75 0.50 0.25 0 0 10 20 30 40 50 Figure 8. Total Capacitance vs. Reverse Voltage—HSMS-280A Series. 1 2 1.5 VR – REVERSE VOLTAGE (V) Figure 7. Dynamic Resistance vs. Forward Current. 5 1.25 0 100 I F – FORWARD CURRENT (mA) 0 1 VR – REVERSE VOLTAGE (V) C T – CAPACITANCE (pF) C T – CAPACITANCE (pF) 100 1 TA = +125°C TA = +75°C TA = +25°C 10 0 2 1 0.1 100 15 Figure 5. Reverse Current vs. Reverse Voltage at Temperatures— HSMS-281L. 1000 RD – DYNAMIC RESISTANCE (Ω) 5 1000 VR – REVERSE VOLTAGE (V) Figure 4. Reverse Current vs. Reverse Voltage at Temperatures— HSMS-280A Series. C T – CAPACITANCE (pF) I R – REVERSE CURRENT (nA) 100,000 I R – REVERSE CURRENT (nA) 100,000 I R – REVERSE CURRENT (nA) 100,000 0 2 4 6 8 10 12 14 VR – REVERSE VOLTAGE (V) Figure 9. Total Capacitance vs. Reverse Voltage—HSMS-281L. 16 4 Applications Information Introduction — Product Selection Hewlett-Packard’s family of sixlead Schottky products provides unique solutions to many design problems. The first step in choosing the right product is to select the diode type. All of the products in the HSMS-282A family use the same diode chip, and the same is true of the HSMS-281A and HSMS-280A families. Each family has a different set of characteristics which can be compared most easily by consulting the SPICE parameters in Table 1. A review of these data shows that the HSMS-280A family has the highest breakdown voltage, but at the expense of a high value of series resistance (Rs). In applications which do not require high voltage the HSMS-282A family, with a lower value of series resistance, will offer higher current carrying capacity and better performance. The HSMS281A family is a hybrid Schottky (as is the HSMS-280A), offering lower 1/f or flicker noise than the HSMS-282A family. In general, the HSMS-282A family should be the designer’s first choice, with the -280A family reserved for high voltage applications and the HSMS-281A family for low flicker noise applications. Six Lead Applications The HSMS-28xL is an unconnected trio of Schottky diodes. It can be used as a fast SP3T switch, as shown in Figure 11. 1 2 3 4 Figure 13. Clamping Four Lines. Figure 11. SP3T Switch. The unconnected trio can also be used to clamp three data lines, as shown in Figure 12. Note that either polarity of clamping can be provided. Similarly, the HSMS-28xN common anode quad can be used to clamp four data lines against negative noise spikes, as shown in Figure 14. 1 2 3 4 Figure 14. Clamping Four Lines. Figure 12. Clamping Three Lines. Table 1. SPICE Parameters. Parameter Units HSMS-280A HSMS-281A HSMS-282A BV CJ0 EG IBV IS N RS PB (VJ) PT (XTI) M V pF eV A A 75 1.6 .69 10E-5 3 x 10E-8 1.08 30 0.65 2 0.5 25 1.1 .69 10E-5 4.8 x 10E-9 1.08 10 0.65 2 0.5 15 0.7 .69 10E-4 2.2 x10E-8 1.08 6.0 0.65 2 0.5 Ω V The HSMS-28xM six lead product is designed to clamp four data lines to ground, protecting against positive noise spikes, as shown in Figure 13. The HSMS-28xP is open bridge quad is designed for sampling circuits, as shown in Figure 15. Note that the bridge is closed at opposite ends by external connections (a trace on the circuit board). sample point sampling pulse Figure 15. Sampling Circuit. 5 The differential detector is often used to provide temperature compensation for a Schottky detector, as shown in Figure 16. bias matching network differential amplifier The HSMS-28xR is an open ring quad, useful in double balanced mixers as shown in Figure 18. As was the case with the bridge product, the quad is closed using external connections. LO in RF in IF out Figure 16. Voltage Doubler. Figure 18. Double Balanced Mixer. These circuits depend upon the use of two diodes having matched Vf characteristics over all operating temperatures. This is best achieved by using two diodes in a single package, such as the HSMS-2825 in the SOT-143 package. However, such circuits generally use single diode detectors, either series or shunt mounted diode. The voltage doubler (HP Application Note 956-4) offers the advantage of twice the output voltage for a given input power. The two concepts can be combined into the differential voltage doubler, as shown in Figure 17. The advantage of an open ring quad can be seen in Figure 19, where two HSMS-28xR products are used to make an eight diode double balanced mixer having very low distortion. bias differential amplifier matching network Figure 17. Differential Voltage Doubler. Here, all four diodes are matched in their Vf characteristics, because they came from adjacent sites on the wafer. LO in RF in IF out Figure 19. Low Distortion Mixer. Other configurations of six lead Schottky products can be used to solve circuit design problems while saving space and cost. Thermal Considerations The obvious advantage of the SOT-363 over the SOT-143 is combination of smaller size and two extra leads. However, the copper leadframe in the SOT-363 has a thermal conductivity four times higher than the Alloy 42 leadframe of the SOT-143, which enables it to dissipate more power. The maximum junction temperature for these three families of Schottky diodes is 150°C under all operating conditions. The follow- ing equation, equation (1), applies to the thermal analysis of diodes: T j = (V f I f + PRF) θ jc + Ta where Tj = junction temperature Ta = diode case temperature θjc = thermal resistance VfIf = DC power dissipated PRF = RF power dissipated Equation (1). Note that θjc, the thermal resistance from diode junction to the foot of the leads, is the sum of two component resistances, θjc = θpkg + θchip Equation (2). Package thermal resistance for the SOT-363 package is approximately 100°C/W, and the chip thermal resistance for these three families of diodes is approximately 40°C/W. The designer will have to add in the thermal resistance from diode case to ambient — a poor choice of circuit board material or heat sink design can make this number very high. Equation (1) would be straightforward to solve but for the fact that diode forward voltage is a function of temperature as well as forward current. The equation, equation (3), for Vf is: If = IS 11600 (Vf – If Rs) nT e –1 where n = ideality factor T = temperature in °K Rs = diode series resistance Equation (3). 6 and IS (diode saturation current) is given by 2 n Is = I 0 T ) ( 298 – 4060 e 1 ( 1T – 298 ) Equation (4). Equations (1) and (3) are solved simultaneously to obtain the value of junction temperature for given values of diode case temperature, DC power dissipation and RF power dissipation. Assembly Instructions SOT-363 PCB Footprint A recommended PCB pad layout for the miniature SOT-363 (SC-70, 6 lead) package is shown in Figure 20 (dimensions are in inches). This layout provides ample allowance for package placement by automated assembly equipment without adding parasitics that could impair the performance. 0.026 SMT Assembly Reliable assembly of surface mount components is a complex process that involves many material, process, and equipment factors, including: method of heating (e.g., IR or vapor phase reflow, wave soldering, etc.) circuit board material, conductor thickness and pattern, type of solder alloy, and the thermal conductivity and thermal mass of components. Components with a low mass, such as the SOT-363 package, will reach solder reflow temperatures faster than those with a greater mass. HP’s SOT-363 diodes have been qualified to the time-temperature profile shown in Figure 21. This profile is representative of an IR reflow type of surface mount assembly process. passes through one or more preheat zones. The preheat zones increase the temperature of the board and components to prevent thermal shock and begin evaporating solvents from the solder paste. The reflow zone briefly elevates the temperature sufficiently to produce a reflow of the solder. The rates of change of temperature for the ramp-up and cooldown zones are chosen to be low enough to not cause deformation of the board or damage to components due to thermal shock. The maximum temperature in the reflow zone (TMAX) should not exceed 235 °C. These parameters are typical for a surface mount assembly process for HP SOT-363 diodes. As a general guideline, the circuit board and components should be exposed only to the minimum temperatures and times necessary to achieve a uniform reflow of solder. After ramping up from room temperature, the circuit board with components attached to it (held in place with solder paste) 250 TMAX 0.075 0.016 Figure 20. PCB Pad Layout (dimensions in inches). TEMPERATURE (°C) 0.035 200 150 Reflow Zone 100 Preheat Zone Cool Down Zone 50 0 0 60 120 180 TIME (seconds) Figure 21. Surface Mount Assembly Profile. 240 300 7 Package Dimensions Outline SOT-363 (SC-70 6 Lead) 1.30 (0.051) REF. 2.20 (0.087) 2.00 (0.079) PACKAGE MARKING CODE 1.35 (0.053) 1.15 (0.045) XX 0.650 BSC (0.025) 0.425 (0.017) TYP. 2.20 (0.087) 1.80 (0.071) 0.10 (0.004) 0.00 (0.00) 0.30 REF. 1.00 (0.039) 0.80 (0.031) 0.25 (0.010) 0.15 (0.006) 10° 0.30 (0.012) 0.10 (0.004) 0.20 (0.008) 0.10 (0.004) DIMENSIONS ARE IN MILLIMETERS (INCHES) Part Number Ordering Information Part Number HSMS-28XA-TR1* HSMS-28XA-BLK* HSMS-281L-TR1 HSMS-281L-BLK No. of Devices 3000 100 3000 100 * where X = 0 or 2; A = L, M, N, P or R Container 7" Reel antistatic bag 7" Reel antistatic bag Device Orientation REEL TOP VIEW END VIEW 4 mm 8 mm CARRIER TAPE USER FEED DIRECTION ## ## ## ## Note: “##” represents Package Marking Code. Package marking is right side up with carrier tape perforations at top. Conforms to Electronic Industries RS-481, “Taping of Surface Mounted Components for Automated Placement.” Standard Quantity is 3,000 Devices per Reel. COVER TAPE Tape Dimensions and Product Orientation For Outline SOT-363 (SC-70, 6 Lead) P P2 D P0 E F W C D1 t1 (CARRIER TAPE THICKNESS) Tt (COVER TAPE THICKNESS) K0 8° MAX. A0 DESCRIPTION B0 SYMBOL SIZE (mm) SIZE (INCHES) LENGTH WIDTH DEPTH PITCH BOTTOM HOLE DIAMETER A0 B0 K0 P D1 2.24 ± 0.10 2.34 ± 0.10 1.22 ± 0.10 4.00 ± 0.10 1.00 + 0.25 0.088 ± 0.004 0.092 ± 0.004 0.048 ± 0.004 0.157 ± 0.004 0.039 + 0.010 DIAMETER PITCH POSITION D P0 E 1.55 ± 0.05 4.00 ± 0.10 1.75 ± 0.10 0.061 ± 0.002 0.157 ± 0.004 0.069 ± 0.004 CARRIER TAPE WIDTH THICKNESS W t1 8.00 ± 0.30 0.255 ± 0.013 0.315 ± 0.012 0.010 ± 0.0005 COVER TAPE WIDTH TAPE THICKNESS C Tt 5.4 ± 0.10 0.062 ± 0.001 0.205 ± 0.004 0.0025 ± 0.00004 DISTANCE CAVITY TO PERFORATION (WIDTH DIRECTION) F 3.50 ± 0.05 0.138 ± 0.002 CAVITY TO PERFORATION (LENGTH DIRECTION) P2 2.00 ± 0.05 0.079 ± 0.002 CAVITY PERFORATION 5° MAX. For technical assistance or the location of your nearest Hewlett-Packard sales office, distributor or representative call: Americas/Canada: 1-800-235-0312 or 408-654-8675 Far East/Australasia: Call your local HP sales office. Japan: (81 3) 3335-8152 Europe: Call your local HP sales office. Data subject to change. Copyright © 1997 Hewlett-Packard Co. Printed in U.S.A. 5966-2049E (10/97)