Diodes Incorporated has introduced a pair of N-channel MOSFETs offering designers of Voice over Internet protocol (VoIP) communications equipment a more rugged solution that significantly reduces circuit complexity and cost.
The ZXMN15A27K and ZXMN20B28K are specifically designed to meet the stringent requirements of the primary switch position in transformer based Subscriber Line Interface Circuits (SLIC) DC/DC converters in a variety of VoIP applications, including voice over broadband systems, PBX systems, cable and DSL gateways.
The devices feature breakdown voltages (BVDSS) of 150V and 200V respectively and will withstand the high pulse avalanche energy and commutation modes in the SLIC environment without the need for additional protection circuitry. Combined with the right choice of transformer, the MOSFETs are capable of driving line voltages beyond 150V and supplying multiple subscriber lines at loop lengths exceeding 6km.
The low input capacitance of these MOSFETs makes them easy to drive directly from the SLIC control IC with minimal or no buffering, further simplifying circuit design and reducing component count and cost. The ZXMN20B28K is also capable of low gate drive at logic level.
Provided in the TO252-3L package, the ZXMN15A27K and ZXMN20B28K are priced at $0.28USD in 10k quantities.