AS394-HYB (AS194-HYB) is a DIP-8 module which contains matched monolithic NPN transistor pair
The AS394 (with an order of magnitude improvement in matching over conventional transistor pair ) with improved heatsink possibility and place for mounting SMT thermosensor (2010 size).
Electrical parameters - according to datasheet of AS194DE/AS394DE (See Downloads tab)
Heatsink is soldered to Exposed Pad (exposed pad isolated from substrate) of AS194DE/AS394DE providing low Juntion-Ambient thermoresistance. Pins 4 and 5 of module are connected only to SMT thermosensor (2010 size).
Thermosensor can be placed over heatsink, allowing good thermocontact (dielectric) to heatsink with the help of heatconductive material. Thermosensor not mounted.