19-4503; Rev 0; 4/09 3-Channel, Low-Leakage ESD Protector Features The MAX14541E low-capacitance Q15kV ESD-protection diode array is designed to protect sensitive electronics attached to communication lines. Each channel consists of a pair of diodes that steer ESD current pulses to VCC or GND. S High-Speed Data Line ESD Protection The MAX14541E protects against ESD pulses up to Q15kV Human Body Model (HBM) and Q15kV Air-Gap Discharge, as specified in IEC 61000-4-2. The device has a 6pF (typ) on-capacitance per channel, making them ideal for use on high-speed data I/O interfaces. S 6pF (typ) Low Input Capacitance ±15kV Human Body Model ±15kV IEC 61000-4-2 Air-Gap Discharge ±8kV IEC 61000-4-2 Contact Discharge S 1nA (max) Low-Leakage Current S +0.9V to +16V Supply Voltage Range S 5-Pin SC70 (2.0mm x 2.2mm) Package The MAX14541E is a triple I/O protector designed for biometric connectors, portable connectors, and SVGA video connections with ultra-low leakage current. Ordering Information The device is available in a 5-pin SC70 package and is specified over the -40NC to +125NC automotive operating temperature range. Applications Glucose Meters PART TEMP RANGE PINPACKAGE TOP MARK MAX14541EAXK+T -40NC to +125NC 5 SC70 ATY +Denotes a lead(Pb)-free/RoHS-compliant package. MP3 Players T = Tape and reel. Digital Cameras Handheld Equipment Pin Configuration TOP VIEW VCC 1 GND 2 I/O-1 3 + 5 I/O-3 4 I/O-2 MAX14541E SC70 ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX14541E General Description MAX14541E 3-Channel, Low-Leakage ESD Protector ABSOLUTE MAXIMUM RATINGS (Voltages referenced to GND.) VCC to GND............................................................-0.3V to +18V I/O-1, I/O-2, I/O-3 to GND......................... -0.3V to (VCC + 0.3V) Continuous Power Dissipation (TA = +70NC) 5-Pin SC70 (derate 3.1mW/NC above +70NC)..........246.9mW Thermal Resistance (Note 1) BJA.............................................................................324NC/W BJC.............................................................................115NC/W Operating Temperature Range......................... -40NC to +125NC Storage Temperature Range............................. -65NC to +150NC Junction Temperature......................................................+150NC Lead Temperature (soldering, 10s).................................+300NC Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. 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 in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VCC = +5V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 2) PARAMETER SYMBOL Supply Voltage VCC Supply Current ICC Diode Forward Voltage VF CONDITIONS VC TYP 0.9 1 IF = 10mA, TA = +25°C TA = +25°C, ±15kV Human Body Model, IF = 10A Channel Clamp Voltage (Note 3) MIN 0.65 Positive transients MAX UNITS 16 V 100 nA 0.95 V VCC + 25 V Negative transients -25 TA = +25°C, ±8kV Contact Discharge (IEC 61000-4-2), IF = 24A Positive transients VCC + 60 Negative transients -60 TA = +25°C, ±15kV Air-Gap Discharge (IEC 61000-4-2), IF = 45A Positive transients VCC + 100 V Negative transients -100 V V Channel Leakage Current (Note 4) TA = -40°C to +50°C -1 +1 nA TA = -40°C to +125°C -1 +1 µA I/O Capacitance Bias of VCC/2, f = 1MHz (Note 4) 7 pF 6 ESD PROTECTION Human Body Model ±15 kV IEC 61000-4-2 Air-Gap Discharge ±15 kV IEC 61000-4-2 Contact Discharge ±8 kV Note 2: Parameters are 100% production tested at TA = +25°C. Specifications over temperature guaranteed by design only. Note 3: Idealized clamp voltages. See the Applications Information section for more information. Note 4: Guaranteed by design, not production tested. 2 _______________________________________________________________________________________ 3-Channel, Low-Leakage ESD Protector 0.1 VCC = 5V MAX14541E toc02 1.0 10 I/O TO VCC I/O LEAKAGE CURRENT (nA) VCC = 12V CLAMP VOLTAGE (V) 0.9 I/O TO GND 0.8 1 VCC = 12V 0.1 0.01 VCC = 3.3V 0.001 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (oC) 10 30 50 70 90 110 DC CURRENT (mA) 130 INPUT CAPACITANCE vs. INPUT VOLTAGE VCC = 3.3V 6 VCC = 5V 4 2 10 MAX14541E toc05 MAX14541E toc04 10 INPUT CAPACITANCE (pF) VCC = 3.3V -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (oC) 150 INPUT CAPACITANCE vs. INPUT VOLTAGE 8 VCC = 5V 0.001 0.7 VCC = 12V INPUT CAPACITANCE (pF) SUPPLY CURRENT (nA) 10 0.01 1.1 MAX14541E toc01 100 1 I/O LEAKAGE CURRENT vs. TEMPERATURE CLAMP VOLTAGE vs. DC CURRENT MAX14541E toc03 SUPPLY CURRENT vs. TEMPERATURE 8 6 4 2 0 0 0 1 2 3 INPUT VOLTAGE (V) 4 5 0 2 4 6 8 INPUT VOLTAGE (V) 10 12 _______________________________________________________________________________________ 3 MAX14541E Typical Operating Characteristics (VCC = +5V, TA = +25NC, unless otherwise noted.) MAX14541E 3-Channel, Low-Leakage ESD Protector _______________________________________________________________Pin Description PIN NAME FUNCTION 1 VCC Power-Supply Input. Bypass VCC to GND with a 0.1FF ceramic capacitor as close as possible to the device. 2 GND Ground. Connect GND with a low-impedance connection to the ground plane. 3 I/O-1 ESD-Protected Channel 4 I/O-2 ESD-Protected Channel 5 I/O-3 ESD-Protected Channel __________________________________________________________Functional Diagram MAX14541E VCC I/O-1 I/O-2 I/O-3 GND 4 _______________________________________________________________________________________ 3-Channel, Low-Leakage ESD Protector The MAX14541E low-leakage, low-capacitance, Q15kV ESD-protection diode arrays are suitable for high-speed and general-signal ESD protection. Low input capacitance makes this device ideal for ESD protection of high-speed signals. Each channel consists of a pair of diodes that steer ESD current pulses to VCC or GND. The MAX14541E is a 3-channel device (see the Functional Diagram). The MAX14541E is designed to work in conjunction with a device’s intrinsic ESD protection. The MAX14541E limits the excursion of the ESD event to below Q25V peak voltage when subjected to the Human Body Model waveform. When subjected to the IEC 61000-4-2 Contact Discharge waveform, the peak voltage is limited to Q60V. The peak voltage is limited to Q100V when subjected to Air-Gap Discharge. The device protected by the MAX14541E must be able to withstand these peak voltages, plus any additional voltage generated by the parasitic of the board. ___________Applications Information Design Considerations Maximum protection against ESD damage results from proper board layout (see the Layout Recommendations section). A good layout reduces the parasitic series inductance on the ground line, supply line, and protected signal lines. The MAX14541E ESD diodes clamp the voltage on the protected lines during an ESD event and shunt the current to GND or VCC. In an ideal circuit, the clamping voltage (VC) is defined as the forward voltage drop (VF) of the protection diode, plus any supply voltage present on the cathode. where IESD is the ESD current pulse. During an ESD event, the current pulse rises from zero to peak value in nanoseconds (Figure 2). For example, in a +15kV IEC 61000-4-7 Air-Gap Discharge ESD event, the pulse current rises to approximately 45A in 1ns (di/dt = 45 x 109). An inductance of only 10nH adds an additional 450V to the clamp voltage, and represents approximately 0.5in of board trace. Regardless of the device’s specified diode clamp voltage, a poor layout with parasitic inductance significantly increases the effective clamp voltage at the protected signal line. Minimize the effects of parasitic inductance by placing the MAX14541E as close as possible to the connector (or ESD contact point). A low-ESR 0.1FF capacitor is required between VCC and GND to get the maximum ESD protection possible. This bypass capacitor absorbs the charge transferred by a positive ESD event. Ideally, the supply rail (VCC) would absorb the charge caused by a positive ESD strike without changing its regulated value. All power supplies have an effective output impedance on their positive rails. If a power supply’s effective output impedance is 1I, then by using V = I x R, the clamping voltage of VC increases by the equation VC = IESD x ROUT. A +8kV IEC 61000-4-2 ESD event generates a current spike of 24A. The clamping voltage increases by VC = 24A x 1I, or VC = 24V. Again, a poor layout without proper bypassing increases the clamping voltage. A ceramic chip capacitor mounted as close as possible to the MAX14541E VCC pin is the best choice for this application. A bypass capacitor should also be placed as close as possible to the protected device. For positive ESD pulses: POSITIVE SUPPLY RAIL VC = VCC + VF L2 For negative ESD pulses: VC = -VF The effect of the parasitic series inductance on the lines must also be considered (Figure 1). For positive ESD pulses: d(I ) d(I ) VC = VCC + VF(D1) + L1 × ESD + L2 × ESD dt dt For negative ESD pulses: d(I ) d(I ) VC = − VF(D2) + L1 × ESD + L3 × ESD dt dt D1 L1 PROTECTED LINE I/O_ D2 L3 GROUND RAIL Figure 1. Parasitic Series Inductance _______________________________________________________________________________________ 5 MAX14541E ________________Detailed Description standard is generally lower than that measured using the Human Body Model. Figure 2 shows the current waveform for the Q8kV IEC 61000-4-2 Level 4, ESD Contact Discharge test. The Air-Gap Discharge test involves approaching the device with a charged probe. The Contact Discharge method connects the probe to the device before the probe is energized. I 100% 90% IPEAK MAX14541E 3-Channel, Low-Leakage ESD Protector RC 1MI 10% tR = 0.7ns to 1ns t 30ns CHARGE-CURRENTLIMIT RESISTOR 60ns Figure 2. IEC 61000-4-2 ESD Generator Current Waveform HIGHVOLTAGE DC SOURCE Cs 100pF RD 1.5kI DISCHARGE RESISTANCE DEVICE UNDER TEST STORAGE CAPACITOR ESD Protection ESD protection can be tested in various ways. The MAX14541E are characterized for protection to the following limits: U Q15kV using the Human Body Model U Q8kV using the Contact Discharge Method specified in IEC 61000-4-2 U Q15kV using the IEC 61000-4-2 Air-Gap Discharge Method ________________ESD Test Conditions ESD performance depends on a number of conditions. Contact Maxim for a reliability report that documents test setup, methodology, and results. Figure 3. Human Body ESD Test Model IP 100% 90% Ir AMPERES 36.8% 10% 0 0 tRL Human Body Model Figure 3 shows the Human Body Model, and Figure 4 shows the current waveform it generates when discharged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of interest which is then discharged into the device through a 1.5kI resistor. TIME tDL CURRENT WAVEFORM Figure 4. Human Body Model Current Waveform RC 50I to 100I CHARGE-CURRENTLIMIT RESISTOR IEC 61000-4-2 The IEC 61000-4-2 standard covers ESD testing and performance of finished equipment. The MAX14541E helps users design equipment that meets Level 4 of IEC 61000-4-2. The main difference between tests done using the Human Body Model and IEC 61000-4-2 Model is higher peak current in IEC 61000-4-2. Because series resistance is lower in the IEC 61000-4-2 ESD test model (Figure 5), the ESD-withstand voltage measured to this PEAK-TO-PEAK RINGING (NOT DRAWN TO SCALE) HIGHVOLTAGE DC SOURCE Cs 150pF RD 330I DISCHARGE RESISTANCE STORAGE CAPACITOR Figure 5. IEC 61000-4-2 ESD Test Model 6 _______________________________________________________________________________________ DEVICE UNDER TEST 3-Channel, Low-Leakage ESD Protector Proper circuit-board layout is critical to suppress ESDinduced line transients (see Figure 6). The MAX14541E clamps to 100V; however, with improper layout, the voltage spike at the device can be much higher. A lead inductance of 10nH with a 45A current spike results in an additional 450V spike on the protected line. It is essential that the layout of the PCB follows these guidelines: 1) Minimize trace length between the connector or input terminal, I/O_, and the protected signal line. MAX14541E __________Layout Recommendations L2 VCC L1 PROTECTED LINE NEGATIVE ESD CURRENT PULSE PATH TO GROUND 2) Use separate planes for power and ground to reduce parasitic inductance and to reduce the impedance to the power rails for shunted ESD current. D1 VC I/O_ PROTECTED CIRCUIT D2 3) Ensure short low-inductance ESD transient return paths to GND and VCC. 4) Minimize conductive power and ground loops. L3 GND 5) Do not place critical signals near the edge of the PCB. 6) Bypass VCC to GND with a low-ESR ceramic capacitor as close as possible to VCC. Figure 6. Layout Considerations 7) Bypass the supply of the protected device to GND with a low-ESR ceramic capacitor as close as possible to the supply pin. ___________________________________________________Typical Application Circuit I/0 I/0 LINE I/0_ VCC VCC PROTECTED CIRCUIT 0.1µF 0.1µF MAX14541E _______________________________________________________________________________________ 7 MAX14541E 3-Channel, Low-Leakage ESD Protector __________________________Chip Information Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. PROCESS: BiCMOS PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 5 SC70 X5+1 21-0076 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 8 © 2009 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.