Octal Switch Delivers Stout ESD Protection

The ISL54230, an octal switch suited for high-end cell phone applications, is small and flexible enough to enable optimizing of signal routing of the many signal types found in such portable devices. The ISL54230 has eight individual single-pole, double-throw (SPDT) switches whose performance has been carefully designed to enable them to pass a wide range of precision voice and data signals, including high-speed USB, UART, PCM, audio and power. With the addition of simple logic control, the switches can be configured to multiplex between pairs of signals like USB 2.0 high-speed ports, or between groups of signals like SIM card clock, data, and power lines. To minimize board space, the signal pins on the ISL54230 have been arranged in a “flow-through” manner to avoid signal crossovers on the PCB. Unused switches can be powered down as required under logic control. For dual-mode cell phones, the ISL54230 allows dual baseband chips to access either of two SIM cards while allowing the unused SIM card to be powered down in order to minimize battery drain. All signal lines have greater than 8-kV ESD protection allowing for much safer SIM card insertion and removal. Switches offer high-speed (480 Mb/s) and full-speed (12 Mb/s) signaling capability per USB 2.0 specs and are compliant with USB 2.0 short-circuit and overvoltage requirements. Supply range is from 2.0 V to 5.5 V. The ISL54230 is available in a 36-bump, 2.53-mm x 2.53-mm WL-CSP package for $1.53 each in lots of 1000. A 32-lead, 5-mm x 5-mm TQFN package costs $1.40 each in similar quantities. INTERSIL CORP., Milpitas, CA. (888) 468-3774.