Latest devices offer direct replacement for popular couplers while improving insulation peak voltage
Toshiba Electronics Europe (TEE) has expanded its family of general purpose transistor photocouplers* with its first devices in a small, low-profile SO4 half-pitch package. The TLP290 and TLP291 can be used up to the maximum permissible operating isolation voltage of 707Vpk defined by EN 60747-5-5, and provide guaranteed operation between -55?C and 110?C.
Featuring the same reference pad dimensions as Toshiba’s previous TLP280 and TLP281, the new TLP290 and TLP291 allow designers to replace their predecessors in existing circuits without system re-design. Target applications include AC adaptors, switching power supplies, programmable logic controllers and inverter circuits.
Toshiba’s TLP290 consists of a photo transistor that is optically coupled to two GaAs infrared LEDs, which are connected in an inverse parallel configuration. The device can operate directly from an AC input current. The TLP291 comprises a photo transistor and a single GaAs LED. Both of the couplers have a minimum rated isolation voltage of 3750Vrms.
Despite board mounting dimensions of just 7mm x 2.6mm, and a profile of only 2.1mm, the new transistor couplers offer guaranteed creepage and clearance distances of 5mm and a guaranteed insulation thickness of 0.4mm. As a result they meet the reinforced insulation requirements of international safety standards.
The new devices have a minimum collector-emitter voltage rating of 80V and offer current transfer ratios from 50% to 400% (IF = 5mA, VCE = 5V, Ta = 25?C).