DB3, DB4, SMDB3 Datasheet Diac Features V : 32 V and 40 V BO Low breakover current DO-35 Breakover voltage symmetry : 3V ECOPACK 2 compliant 2 Applications 3 Triggering device for Triac or SCR based motor / light dimmer 1 SOT-23 32 V trigger device for oscillator circuit Pin 1 and 3 must be shorted Start up triggering in lighting ballast for CFL, TL or LED lamps together Description Functioning as a trigger diode with a fixed voltage reference, the DB3/DB4 series can be used in conjunction with triacs for simplified gate control circuits or as a starting element in fluorescent lamp ballasts. The surface mount SOT23-3L package allows compact, SMD based designs for automated manufacturing. Product status link DB3 DB4 SMDB3 Product summary V Part number BO SMDB3 28 - 36 V DB3 28 - 36 V DB4 35 - 45 V DS2125 - Rev 3 - December 2018 www.st.com For further information contact your local STMicroelectronics sales office.DB3, DB4, SMDB3 Characteristics 1 Characteristics Table 1. Absolute maximum ratings (limiting values), T = 25 C unless otherwise specified j Symbol Parameter Value Unit SMDB3 1.00 A I Repetitive peak on-state current, t = 20 s, F = 120 Hz TRM p DB3 / DB4 2.00 A T Storage junction temperature range -40 to +125 C stg T Operating junction temperature range -40 to +125 C j Table 2. Electrical characteristics (T = 25 C unless otherwise specified) j Symbol Parameter Test conditions SMDB3 DB3 DB4 Unit Min. 28 28 35 (1) (2) V Breakover voltage C = 10 nF Typ. 32 32 40 V BO Max. 36 36 45 (2) I V - V I Breakover voltage symmetry Max. 3 3 3 V BO1 BO2 C = 10 nF (1) V V and V at 10 mA Min. 10 5 5 V Dynamic breakover voltage BO F (1) V See Figure 2. Test circuit, (R = 20 ) Min. 10 5 5 V O Output voltage (1) (2) I Max. 10 50 50 A BO Breakover current C = 10 nF (1) t See Figure 3. Rise time measurement Max. 0.5 2 2 s r Rise time (1) I V = 0.5 x V max Max. 1 10 10 A R Leakage current R BO (1) I Peak current See Figure 2. Test circuit Min. 1 0.30 0.30 A P 1. Applicable to both forward and reverse directions. 2. Connected in parallel to the device DS2125 - Rev 3 page 2/11