tf256th.pdf datasheet:

Ordering number : ENA1617BTF256THN-Channel JFEThttp://onsemi.com20V, 140 to 450 A, 1.7mS, VTFPFeatures High gain : GV=2.7dB typ (VCC=2V, RL=2.2k , Cin=5pF, VIN=10mV, f=1kHz) Ultrasmall package facilitates miniaturization in end products Best suited for use in electret condenser microphone for audio equipments and telephones Excellent transient characteristics Adoption of FBET process Halogen free complianceSpecificationsAbsolute Maximum Ratings at Ta=25CParameter Symbol Conditions Ratings UnitGate-to-Drain Voltage VGDO --20 VGate Current IG 10 mADrain Current ID 1 mAAllowable Power Dissipation PD 100 mWJunction Temperature Tj 150 CStorage Temperature Tstg --55 to +150 CStresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended O