ESD Suppressor Technology
ESD suppressors are devices that are placed in parallel with the circuitry they are providing the protection for. They are placed between the potential ESD transient source or entry point into the circuit and the protected electronics. Data ports and USB hub connections are two examples of potential ESD entry points. They are designed to be off and invisible to the normal operation of the device yet if an ESD event occurs, react very quickly to shunt the energy and voltage of the transient to ground. Physical size, cost, reaction time, leakage current, as well as transient voltage and current or power handling are the key characteristics that design engineers take into account when choosing an ESD solution. There are four main types of ESD suppressors available on the market today, each with different advantages and disadvantages.
Polymeric ESD suppressors
Polymeric ESD suppressors are similar to Stackpole’s ESD / ESDU in that they are a spark gap based device. “Spark gap” devices have designated space between the electrodes to keep the device “off” until a ESD event occurs. When a significant ESD event occurs, the voltage will cross the gap and trigger the device to turn on. The difference for the polymeric based suppressors is that there is polymer between the two potential electrodes where the Stackpole part has an air gap. The polymeric ESD device can’t achieve the low capacitance that an air gap device can and thus doesn’t react as fast. Still polymeric ESD suppressors are typically used because of their low leakage current, relatively high voltage pulse withstanding and their low breakdown voltages. However they use is limited by their higher trigger and higher clamping voltages meaning relatively higher ESD transients are needed to cause the part to conduct and the voltage across the part during the on phase conduction is also higher. Thus, electronics with low voltage withstanding thresholds can’t use this type of device. Pricing varies greatly based on quantity and other parameters, but the general price range is $0.20 each to $0.75 each in full reel quantities.
Multilayer varistors such as Stackpole’s ZVE series are used for higher current handling and lower breakdown voltage. However, multilayer varistors have higher leakage current and higher capacitance which leads to slower response times. Because of this, varistors are only used for lower speed devices such as low speed video, audio, and data communication ports, and low resolution LCD I/O ports. Pricing for this series ranges from $0.094 each to $0.174 each in full reel quantities.
TVSD (Diode) ESD Suppressors
TVSD ESD suppressors are used because of their low trigger voltage and low clamping voltage compared to multilayer varistors. However their capacitance is comparable to that of the multilayer varistor so they are also typically only used for lower speed protection requirements. TVSD devices also have higher leakage current than polymeric or air gap technology suppressors. Full reel quantity pricing ranges from $0.03 to $0.15 each.
ESD / ESDU series suppression chips and ESA / ESAU series suppression arrays
Stackpole’s ESD / ESDU series suppression chips and ESA / ESAU series suppression arrays is one of the only devices on the market that uses an air gap technology which provides extremely low capacitance characteristics allowing protection for the highest speed USB connections, HDMI, and other high speed data communication ports. These devices are well suited for protection of connection points on all HDTV types, MP3 hubs, DVR, scanners, printers, PC’s, and PDA’s. In addition to low capacitance, these series offer high pulse voltage withstanding, low leakage current, and lower clamping voltage than similar products in the other technologies. Pricing ranges from $0.030 each to $0.060 each for the ESD / ESDU in full reel quantities and $0.20 each to $0.25 each for the ESA / ESAU in full reel quantities.
The graphic below shows how the ESD / ESDU / ESA / ESAU are the only options for the highest speed USB, HDMI, and other high speed communications ports.
Regional Sales Manager Contact Information:
For more information about Stackpole products, contact us at:
Stackpole Electronics, Inc.
2700 Wycliff Road Suite 410,
Raleigh NC 27607
Stackpole Electronics Inc. is a leading global manufacturer of resistors supplying to the worlds largest OEMs, contract manufacturers and distributors. Headquartered in Raleigh, N.C., the privately held company began manufacturing in 1928 as part of Stackpole Carbon Company in St. Mary's, Pennsylvania. Now affiliated with Akahane Electronics, Stackpole has manufacturing facilities in Japan, Taiwan, China and Mexico; warehousing facilities in El Paso, Hong Kong and Japan; and sales offices in Tokyo, Hong Kong and Taiwan.