STMicro Reduces Size Of ESD Protection Diodes By Two-Thirds
STMicroelectronics announced a new series of ESD protection diodes that are said to be 67% smaller than previous-generation alternatives, and withstand the toughest IEC61000-4-2 ESD test pulse as well as deliver low clamping voltages that improve protection for modern, low-voltage ICs.
The ESDALCxx-1U2 family, in the space-saving ST0201 package, has a footprint of 0.18mm². This tiny circuit-saver reduces the board space needed to provide mandatory protection in portable devices such as mobile phones, GPS receivers and MP3 players. In addition to allowing designers to implement extra features in the vacated space, these smaller diodes are also said to simplify circuit board layout. Because their 0.3 x 0.6mm dimensions match the industry-standard 0201 outline for miniature surface-mount passives, it is stated that board designers can quickly select the optimum solder-pad pattern from available CAD component libraries.
ESD protection diodes are usually placed on power or signal lines that are vulnerable to ESD strike; typically those that are routed to external connectors or switches. These vulnerable lines can include charger ports, keypads, and the side buttons of mobile phone handsets. When an ESD pulse occurs, the diode protects delicate chips from the pulse energy by diverting the surge current to ground and clamping the voltage spike to a low level that the IC can safely tolerate. The protection diode itself must also be able to withstand the surge energy applied.
ST has combined small size with high surge-handling capabilities to create this new family comprising the ESDALC3V9-1U2, ESDALC6V1-1U2 and ESDALC14V2-1U2. The devices have breakdown voltage of 3.9, 6.1 and 14.2V respectively, allowing designers to choose the optimum device to achieve the best clamping voltage for the ICs being protected. All of the new devices are able to survive multiple strikes up to IEC61000-4-2 Level 4, which specifies a contact-discharge pulse of 8kV and 30A surge current. Additional benefits of the new diodes include low leakage current, which minimizes drain on the battery, and low device capacitance of 6 or 12pF to minimize the effects on signal speeds.
The ESDALC3V9-1U2, ESDALC6V1-1U2, and ESDALC14V2-1U2 are available immediately, in RoHS-compliant packaging, priced at $0.09 each for 100,000 pieces.
