View mmbta42l datasheet:

MOTOROLA Order this document SEMICONDUCTOR TECHNICAL DATA by MMBTA42LT1/D High Voltage Transistors * MMBTA42LT1 NPN Silicon COLLECTOR MMBTA43LT1 3 *Motorola Preferred Device 1 BASE 2 3 EMITTER MAXIMUM RATINGS 1 Rating Symbol MMBTA42 MMBTA43 Unit 2 Collector–Emitter Voltage VCEO 300 200 Vdc Collector–Base Voltage VCBO 300 200 Vdc CASE 318–08, STYLE 6 Emitter–Base Voltage VEBO 6.0 6.0 Vdc SOT–23 (TO–236AB) Collector Current — Continuous IC 500 mAdc DEVICE MARKING MMBTA42LT1 = 1D; MMBTA43LT1 = M1E THERMAL CHARACTERISTICS Characteristic Symbol Max Unit Total Device Dissipation FR–5 Board,(1) PD 225 mW TA = 25°C Derate above 25°C 1.8 mW/°C Thermal Resistance, Junction to Ambient RqJA 556 °C/W Total Device Dissipation PD 300 mW Alumina Substrate,(2) TA = 25°C