TVS Diode Arrays SCR Diode Array for ESD and Transient Overvoltage Protection SP724 The SP724 is a quad array of transient voltage clamping circuits designed to suppress ESD and other transient over-voltage events. The SP724 is used to help protect sensitive digital or analog input circuits on data, signal, or control lines operating on power supplies up to 20VDC. The SP724 is comprised of bipolar SCR/diode structures to protect up to four independent lines by clamping transients of either polarity to the power supply rails. The SP724 offers very low leakage (1nA Typical) and low input capacitance (3pF Typical). Additionally, the SP724 is rated to withstand the IEC 61000-4-2 ESD specification for both contact and air discharge methods to level 4. The SP724 is connected to the sensitive input line and its associated power supply lines. Clamping action occurs during the transient pulse, turning on the diode and fast triggering SCR structures when the voltage on the input line exceeds one VBE threshold above the V+ supply (or one VBE threshold below the V- supply). Therefore, the SP724 operation is unaffected by poor power supply regulation or voltage fluctuations within its operating range. Ordering Information PART NUMBER SP724AHT TEMP. RANGE (oC) -40 to 105 PACKAGE Tape and Reel PKG. NO. Min. Order Qty. P6.064 3000 Features • An Array of 4 SCR/Diode Pairs in 6-Lead SOT-23 • ESD Capability per HBM Standards - IEC 61000-4-2, Direct Discharge . . . . . . . . . . . . . . . . . 8kV (Level 4) - IEC 61000-4-2, Air Discharge . . . . . . . . . . . . . . . . . . 15kV (Level 4) - MIL STD 3015.7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . >8kV • Input Protection for Applications with Power Supplies Up to +20V (Single-Ended Voltage), and ±10V (Differential Voltage) • Peak Current Capability • IEC 61000-4-5 (8/20µs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±3A • Single Pulse, 100µs Pulse Width . . . . . . . . . . . . . . . . . . . . . . . ±2.2A • Low Input Leakage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1nA Typical • Low Input Capacitance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3pF Typical Pinout • Operating Temperature Range . . . . . . . . . . . . . . . . . . . . -40oC to 105oC SP724 (SOT-23) Applications • Microprocessor/Logic Input Protection TOP VIEW 6 5 4 • Data Bus Protection • Analog Device Input Protection • Voltage Clamp Functional Block Diagram 1 2 3 V+ 5 IN 1 V- 2 3, 4 AND 6 IN NOTES: 1. The design of the SP724 SCR/Diode ESD Protection Arrays is covered by Littelfuse patent 4567500. 2. The full ESD capability of the SP724 is achieved when wired in a circuit that includes connection to both the V+ and V- pins. When handling individual devices, follow proper procedures for electrostatic discharge. 246 w w w. l i t t e l f u s e . c o m TVS Diode Arrays SCR Diode Array for ESD and Transient Overvoltage Protection SP724 Absolute Maximum Ratings Thermal Information Continuous Supply Voltage, (V+) - (V-). . . . . . . . . . . . . . . . . . . . . . . . . +20V Thermal Resistance (Typical, Note 3) θJA (oC/W) SOT Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . 220 Maximum Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . .-65oC to 150oC Maximum Junction Temperature . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . 150oC Maximum Lead Temperature (Soldering 10s) . . . . . . . . .. . . . . . . . . . . . . . . . 300oC (SOT - Lead Tips Only) Forward Peak Current, IIN to VCC , GND (Refer to Figure 6). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±2.2A, 100µs ESD Ratings and Capability - See Figure 1, Table 1 CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. NOTE: 3. θJA is measured with the component mounted on an evaluation PC board in free air. Electrical Specifications TA = -40oC to 105oC, VIN = 0.5VCC , Unless Otherwise Specified Forward Voltage Drop IN to VIN to V+ Input Leakage Current Quiescent Supply Current SYMBOL TEST CONDITIONS MIN VSUPPLY TYP UNITS - 20 V V - 2 - VFWDH - 2 - V IIN -10 1 10 nA VFWDL IQUIESCENT IIN = 1A (Peak Pulse) MAX 1 V+ = 20V, V- = GND - - 100 nA Equivalent SCR ON Threshold (Note 6) - 1.1 - V Equivalent SCR ON Resistance VFWD /IFWD (Note 6) - 1.0 - Ω - 3 - pF Input Capacitance CIN 5 NOTES: 4. In automotive and other battery charging systems, the SP724 power supply lines should be externally protected for load dump and reverse battery. When the V+ and V- Pins are connected to the same supply voltage source as the device or control line under protection, a current limiting resistor should be connected in series between the external supply and the SP724 supply pins to limit reverse battery current to within the rated maximum limits. 5. Bypass capacitors of typically 0.01µF or larger should be connected closely between the V+ and V- Pins for all applications. 6. Refer to the Figure 3 graph for definitions of equivalent “SCR ON Threshold” and “SCR ON Resistance”. These characteristics are given here for information to determine peak current and dissipation under EOS conditions. ESD Rating TABLE 1. ESD TEST CONDITIONS ESD rating is dependent on the defined test standard. The evaluation results for various test standards and methods based on Figure 1 are shown in Table 1.3 The SP724 has a Level 4 rating when tested to the IEC 61000-4-2 Human Body Model (HBM) standard and connected in a circuit in which the V+ and V- pins have a return path to ground. Level 4 specifies a required capability greater than 8kV for direct discharge and greater than 15kV for air discharge. STANDARD IEC 61000-4-2 (Level 4) TYPE/MODE RD HBM, Air Discharge HBM, Direct Discharge 330Ω 150pF MIL-STD-3015.7 Modified HBM 1.5kΩ 100pF Standard HBM 1.5kΩ 100pF EIAJ IC121 Machine Model US ESD DS 5.3 Charged Device Model The “Modified” MIL-STD-3015.7 condition is defined as an “in-circuit” method of ESD testing, the V+ and V- pins have a return path to ground.The SP724 ESD capability is greater than 8kV with 100pF discharged through 1.5kΩ. By strict definition of the standard MILSTD-3015.7 method using “pin-to-pin” device testing, the ESD voltage capability is greater than 2kV. CD 330Ω 150pF ±VD 15kV 8kV 8kV † 2kV 0kΩ 200pF 400V 0kΩ NA 3kV † Upper limit of laboratory test set. For the SP724 EIAJ IC121 Machine Model (MM) standard, the ESD capability is typically greater than 1.8kV with 200pF discharged through 0kΩ. The Charged Device model is based upon the self-capacitance of the SOT-23 package through 0kΩ. R1 RD CHARGE SWITCH H.V. SUPPLY ±VD DISCHARGE SWITCH CD IN DUT IEC 1000-4-2: R 1 50 to 100MΩ MIL STD 3015.7: R 1 1 to 10MΩ FIGURE 1. ELECTROSTATIC DISCHARGE TEST w w w. l i t t e l f u s e . c o m 247 TVS DIODE ARRAYS PARAMETER Operating Voltage Range, VSUPPLY = [(V+) - (V-)] (Notes 4, 5) TVS Diode Arrays SCR Diode Array for ESD and Transient Overvoltage Protection SP724 5 TA = 25oC SINGLE PULSE FORWARD SCR CURRENT (A) FORWARD SCR CURRENT (mA) 200 160 120 80 40 0 600 800 1000 1200 TA = 25oC SINGLE PULSE 4 3 2 EQUIV. SAT. ON THRESHOLD ~ 1.1V 1 0 0 1 2 FIGURE 2. LOW CURRENT SCR FORWARD VOLTAGE DROP CURVE FIGURE 3. HIGH CURRENT SCR FORWARD VOLTAGE DROP CURVE +VCC +VCC INPUT DRIVERS OR SIGNAL SOURCES LINEAR OR DIGITAL IC INTERFACE IN 1, 3, 4 AND 6 TO +VCC V+ 0.01µF SP724 V- SP724 INPUT PROTECTION CIRCUIT (1 OF 4 SHOWN) FIGURE 4. TYPICAL APPLICATION OF THE SP724 AS AN INPUT CLAMP FOR OVER-VOLTAGE, GREATER THAN 1VBE ABOVE V+ OR LESS THAN -1V BE BELOW V- 248 3 FORWARD SCR VOLTAGE DROP (V) FORWARD SCR VOLTAGE DROP (mV) w w w. l i t t e l f u s e . c o m TVS Diode Arrays SCR Diode Array for ESD and Transient Overvoltage Protection SP724 Peak Transient Current Capability for Long Duration Surges The peak transient current capability is inversely proportional to the width of the current pulse. Testing was done to fully evaluate the SP724’s ability to withstand long duration current pulses using the circuit of Figure 5. Figure 6 shows the point of overstress as defined by increased leakage in excess of the data sheet published limits. The safe operating range of the transient peak current should be limited to no more than 75% of the measured overstress level for any given pulse width as shown in the curve of Figure 6. + VX VARIABLETIME DURATION CURRENT PULSE GENERATOR R1 CURRENT SENSE - (-) (+) 6 1 + 4 3 The test circuit of Figure 5 is shown with a positive pulse input. For a negative pulse input, the (-) current pulse input goes to an SP724 ‘IN’ input pin and the (+) current pulse input goes to the SP724 V- pin. The V+ to V- supply of the SP724 must be allowed to float. (i.e., It is not tied to the ground reference of the current pulse generator.) - 5 2 SP724 C1 VOLTAGE PROBE R1 ~ 10Ω TYPICAL VX ADJ. 10V/A TYPICAL C1 ~ 100µF Note that two input pins of the SP724 may be paralleled to improve current (and ESD) capability. The sustained peak current capability is increased to nearly twice that of a single pin. FIGURE 5. TYPICAL SP724 PEAK CURRENT TEST CIRCUIT WITH A VARIABLE PULSE WIDTH INPUT 8 5 7 PEAK CURRENT (A) 6 TVS DIODE ARRAYS NOTE: TO ENSURE SAFE OPERATION LIMIT THE MAXIMUM PEAK CURRENT FOR A GIVEN PULSE WIDTH TO BE NO GREATER THAN 75% OF THE VALUES SHOWN. TA = 25oC V+ TO V- SUPPLY = 15V 5 4 3 2 1 0 0.001 0.01 0.1 1 10 100 1000 SQUARE WAVE PULSE WIDTH (ms) FIGURE 6. SP724 TYPICAL NONREPETITIVE PEAK CURRENT PULSE CAPABILITY w w w. l i t t e l f u s e . c o m 249 TVS Diode Arrays SCR Diode Array for ESD and Transient Overvoltage Protection SP724 Small Outline Transistor Plastic Packages (SOT23-6) P6.064 6 LEAD SMALL OUTLINE TRANSISTOR PLASTIC PACKAGE INCHES MILLIMETERS SYMBOL MIN MAX MIN MAX NOTES A 0.036 0.057 0.90 1.45 - A1 0.000 0.0059 0.00 0.15 - A2 0.036 0.051 0.90 1.30 - b 0.0138 0.0196 0.35 0.50 - C 0.0036 0.0078 0.09 0.20 - D 0.111 0.118 2.80 3.00 3 E 0.103 0.118 2.60 3.00 - E1 0.060 0.068 1.50 1.75 3 e 0.0374 Ref 0.95 Ref - e1 0.0748 Ref 1.90 Ref - L 0.004 N 0.023 0.10 6 0o 0.60 6 10o 0o 4, 5 6 10o Rev. 1 2/98 250 w w w. l i t t e l f u s e . c o m TVS Diode Arrays SCR Diode Array for ESD and Transient Overvoltage Protection SP724 SOT23-6 8mm TAPE AND REEL ACCESS HOLE 4.0mm 14.4mm 1.5mm DIA. HOLE 2.0mm 1.75mm C L 8mm 13mm 4.0mm 60mm SOT-23 (8mm POCKET PITCH) 8.4mm USER DIRECTION OF FEED PIN 1 5 GENERAL INFORMATION 1. 3000 PIECES PER REEL. 2. ORDER IN MULTIPLES OF FULL REELS ONLY . 3. MEETS EIA-481 REVISION "A" SPECIFICATIONS. TVS DIODE ARRAYS 180mm COVER TAPE Rev. 0 2/99 w w w. l i t t e l f u s e . c o m 251