2N2646 Unijunction Transistor TO-18 Package Description: The 2N2646 is designed for use in pulse and timing circuits, sensing circuits and thyristor trigger circuits. Features: D Low Peak Point Current: 5A (Max) D Low Emitter Reverse Current: .005A (Typ) D Passivated Surface for Reliability & Uniformity Absolute Maximum Ratings: (TA = +25C unless otherwise specified) Power Dissipation (Note 1), PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300mW RMS Emitter Current, IE(RMS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA Peak Pulse Emitter Current (Note 2), iE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2A Emitter Reverse Voltage, VB2E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30V Interbase Voltage, VB2B1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35V Operating Junction Temperature Range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65 to 125C Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65 to +150C Note 1 Derate 3mW/C increase in ambient temperature. The total power dissipation (available power to Emitter and Base-Two) must be limited by the external circuitry. Note 2 Capacitor discharge - 10F or less, 30 volts or less Electrical Characteristics: (TA = +25C unless otherwise specified) Parameter Intrinsic Standoff Ratio Symbol Interbase Resistance rBB Interbase Resistance Temperature Coefficient arBB Test Conditions Min Typ Max Unit VB2B1 = 10V, Note 3 0.56 - 0.75 - VB2B1 = 3V, IE = 0 4.7 7.0 9.1 k 0.1 - 0.9 %/C Note 3. Intrinsic standoff ratio, is defined by equation: = VP - VF VB2B1 where VP = Peak Point Emitter Voltage VB2B1 = Interbase Voltage VF = Emitter to Base-One Junction Diode Drop ( 0.45V @ 10A) Electrical Characteristics (Cont'd): (TA = +25C unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Emitter Saturation Voltage VEB1(sat) VB2B1 = 10V, IE = 50mA, Note 4 - 3.5 - V Modulated Interbase Current IB2(mod) VB2B1 = 10V, IE = 50mA - 15 - mA VB2E = 30V, IB1 = 0 - 0.005 12 A Emitter Reverse Current IEB20 Peak Point Emitter Current IP VB2B1 = 25V - 1 5 A Valley Point Current IV VB2B1 = 20V, RB2 = 100 4 6 - mA 3 5 - V Base-One Peak Pulse Voltage VOB1 Note 4. Use pulse techniques: Pulse Width ~300s, duty cycle 2% to avoid internal heating due to interbase modulation which may result in erroneous readings. .230 (5.84) Dia Max .195 (4.95) Dia Max .210 (5.33) Max .030 (.762) Max .500 (12.7) Min .018 (0.45) Base 1 Emitter 45 Base 2/Case .041 (1.05)