Intersil's Compact Single Pole/Triple Throw Switches Eliminate Handheld Device Connector Congestion

(Product News, 13 Apr 2009)

Intersil Corp. introduced two switches that provide the industry's optimal solution for eliminating congestion in handheld device connectors. The ISL54214 dual SP3T (single pole/triple throw) switch or 3:1 Mux combines low distortion audio and two accurate USB 2.0 high speed data (480Mbps) signal switching paths in the same low voltage device. The switches enable use of a common mini USB or audio headphone connector in media players and other portable battery-operated products by allowing either two USB transceivers or one USB transceiver -- plus a UART transceiver -- to share pins with an audio codec.

The ISL54217 dual SP3T adds Intersil's comprehensive click and pop elimination circuitry to the switch, enhancing the performance of handheld products by removing audio artifacts.
The audio switch cells in both the ISL54214 and ISL54217 can pass ±1V ground referenced audio signals with ultra low distortion of <0.03 percent THD+N when driving 5mW into 32 Ohm headphone loads. In addition they have a special Muting mode of operation to provide very high isolation between the codec and the headphone or amplifier load. The USB switch cells have very low ON capacitance of just 8pF, resulting in high bandwidth to move USB high speed signals with minimal edge and phase distortion.

Dual USB 2.0 data paths allow multiple chips to share a high speed USB port. Both devices incorporate failsafe power-off protection to prevent USB lock-up or battery drain via USB ports in case of power failure. COM pins in each version can tolerate over voltages beyond the supply rails, meeting USB short circuit requirements with no additional components.