View mmbt5550 datasheet:

MOTOROLA Order this document SEMICONDUCTOR TECHNICAL DATA by MMBT5550LT1/D MMBT5550LT1 High Voltage Transistors * MMBT5551LT1 COLLECTOR NPN Silicon 3 *Motorola Preferred Device 1 BASE 2 3 EMITTER MAXIMUM RATINGS 1 Rating Symbol Value Unit 2 Collector–Emitter Voltage VCEO 140 Vdc Collector–Base Voltage VCBO 160 Vdc CASE 318–08, STYLE 6 SOT–23 (TO–236AB) Emitter–Base Voltage VEBO 6.0 Vdc Collector Current — Continuous IC 600 mAdc 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 Derate above 25°C 2.4 mW/°C Thermal Resistance, Junction to Ambient R