Next Previous PulseGuard ® Suppressors Polymeric ESD Suppressors PGB Series SOT23 Surface Mount ESD Suppressor Product Overview PulseGuard ESD Suppressors help protect sensitive electronic equipment against electrostatic discharge (ESD). They supplement the on-chip protection of integrated circuitry and are best suited for lowvoltage, high-speed applications where low capacitance is important. Data ports utilizing such high-speed protocols as USB 2.0, IEEE1394 and InfiniBandSM can benefit from this new technology. PulseGuard suppressors use polymer composite materials to suppress fast-rising ESD transients (as specified in IEC 61000-4-2 and MIL-STD-883E). Features • Ultra-low capacitance • Low leakage current • Fast response time • 2-lines of protection • Bi-directional • Withstands multiple ESD strikes • Standard JEDEC SOT23 outline • Compatible with pick-and-place processes • Available in 3,000 piece reels Physical Specifications Typical Applications • • • • • • PULSEGUARD® SUPPRESSORS 4 Materials: Servers Laptop/Desktop Computers Network Hardware Computer Peripherals Digital Cameras External Storage Body: Glass Epoxy Terminations: Tin-Lead Soldering Parameters: Wave solder -- 260°C, 10 seconds maximum Reflow solder -- 260°C, 30 seconds maximum Operating Temperature Range: -65°C to 125°C Electrical Characteristics Trigger Voltage1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,000V typical Ordering Information Clamping Voltage1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150V typical CATALOG NUMBER PIECES PER REEL Rated Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24VDC max PGB002ST23WR 3,000 Capacitance2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.055pF Response Time1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <1ns Design Consideration Leakage Current3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <1nA Because of the fast rise-time of the ESD transient, placement of PulseGuard suppressors is a key design consideration. To achieve optimal ESD suppression, the devices should be placed on the circuit board as close to the source of the ESD transient as possible. Install PulseGuard suppressors directly behind the connector so that they are the first board-level circuit component encountered by the ESD transient. They are connected from signal/data line to ground. ESD Pulse Withstand . . . . . . . . . . . . . . . . . . . . . 1,000 pulses minimum 1 Notes: 1. 8 kV direct discharge method, per IEC 61000-4-2. 2. Measured at 1 MHz. 3. Measured at 6 VDC. Testing at fast ESD pulse rates (1-20Hz) may cause a change in leakage current performance (6µA, max). w w w. l i t t e l f u s e . c o m 177 Next Previous PulseGuard ® Suppressors Polymeric ESD Suppressors PGB Series SOT23 Surface Mount ESD Suppressor Generalized PulseGuard Suppressor Response to ESD Generalized I-V Curve (Positive and Negative Polarity ESD Pulses) (Positive and Negative Polarity ESD Pulses) Trigger Voltage Current (A) Voltage (V) Trigger Voltage Clamping Voltage Clamping Voltage Voltage (V) Time (ns) Definitions Capacitance vs. Frequency Trigger Voltage: The measured peak voltage across the ESD suppressor before it transitions from high to low resistance. It is manifested as a “spike” before the clamping voltage is achieved. This voltage is typically well below the damage threshold of on-chip IC protection. ESD Impulse Voltage: Also known as the ESD Threat Voltage. This is the voltage that is “zapped” into the circuit. Voltages generated by people can exceed 15 kV. The IEC 61000-4-2 defines four levels of impulse voltage for testing purposes: AIR DISCHARGE DIRECT DISCHARGE 1 2 kV 2 kV 2 4 kV 4 kV 3 8 kV 6 kV 4 15 kV 8 kV Capacitance (fF) Clamping Voltage: The voltage level to which the ESD impulse voltage is reduced. This is the voltage that the suppressor holds at, until the ESD transient energy is dissipated. SEVERITY LEVEL ** Note: 1,000 fF = 1 pF 70 60 50 40 0.5 DESCRIPTION Carrier Tape Specifications Parts are delivered on 7” (178mm) reel, plastic carrier tape Tt Ds Dd + + + + Tw + Pd Ph + Ps Pw 1.5 2.0 MEASUREMENT (MM) Ct - Cover tape thickness 0.06 Dd - Drive hole diameter 1.50 Ds - Drive hole spacing 4.00 Pd - Pocket depth 1.02 Ph - Pocket height 3.23 Ps - Pocket spacing 4.00 Pw - Pocket width 2.46 Tt - Carrier tape thickness 0.30 Tw - Carrier tape width 8.00 Ct 178 1.0 Frequency (GHz) w w w. l i t t e l f u s e . c o m Next Previous PulseGuard ® Suppressors Polymeric ESD Suppressors PGB Series SOT23 Surface Mount ESD Suppressor Test Set-up for IEC 61000-4-2 Waveform, 2kV-15kV Device under test Tek P6156 Probe (Voltage measurement) Faraday cage Brown tip (x100) KeyTek pulser 2,000- 15,000 V x10 Ground return x10 4 Tektronic TDS 684B PULSEGUARD® SUPPRESSORS Blue tip (x10) .5 ohm shunt (10-5 ohms in parallel) Tek P6156 Probe (Current measurement) Reference Schematics: Equivalent Circuit: Device Dimensions: Recommended Pad Layout: 2.24 (0.088") a + 1 d 2.997 (0.118") 2.032 (0.080") b 3 + c 2 e a b * Dimension "a" is: 0.066 (.026") * Dimension "b" is: 0.076 (.030") A B C D E SOLDER METHOD INCH MM INCH MM INCH MM INCH MM INCH MM Wave Solder 0.050 1.27 0.040 1.016 0.050 1.27 0.090 2.29 0.150 3.81 Reflow Solder 0.050 1.27 0.040 1.016 0.040 1.01 0.080 2.032 0.140 3.56 Note: Pin 3 (common) is typically connected to chassis ground. However, since PulseGuard suppressors are bi-directional, thex system voltage bus can also be used as the ESD “dump”. w w w. l i t t e l f u s e . c o m 179