CURRENT 3.0 Amperes VOLTAGE 200 to 1300 Volts BY251 THRU BY255 Features * Low cost * Diffused junction * High current capability * The plastic material carries U/L recognition 94V-0 DO-201AD 0.210(5.3) 0.188(4.8) DIA. 1.0(25.4) MIN. 0.375(9.5) 0.285(7.2) Mechanical Data * Case : JEDEC DO-201AD molded plastic body * Terminals : Plated axial lead solderable per MIL-STD-750, method 2026 * Polarity : Color band denotes cathode end * Mounting Position : Any * Weight : 0.042 ounce, 1.1 grams 1.0(25.4) MIN. 0.042(1.1) 0.037(0.9) DIA. Dimensions in inches and (millimeters) Maximum Ratings And Electrical Characteristics (Ratings at 25 ambient temperature unless otherwise specified, Single phase, half wave 60Hz, resistive or inductive load. For capacitive load, derate by 20%) Symbols BY251 BY253 BY254 BY255 Units 400 600 800 1000 Volts Maximum recurrent peak reverse voltage VRRM Maximum average forward rectified current at TA=50 I(AV) 3.0 Amps Recurrent peak Forward Current IFRM 20.0 Amps Peak forward surge current 8.3ms half sine wave superimposed on rated load IFSM 100.0 Amps Maximum instantaneous forward voltage at 3.0A VF 1.1 Volts Maximum reverse current at rated DC blocking voltage IR 10.0 A Typical thermal resistance Typical junction capacitance (Note 1) Operating and storage temperature range 200 BY252 RJA 30.0 /W CJ 30.0 pF TJ TSTG Notes: (1) Measured at 1MHz and applied reverse voltage of 4.0V DC. -50 to +150 RATINGS AND CHARACTERISTIC CURVES BY251 THRU BY255 FIG.1-FORWARD CURRENT DERATING CURVE FIG.2-TYPICAL FORWARD CHARACTERISTICS 100 4 10mm 10mm 3 INSTANTANEOUS FORWARD CURRENT(AMPERES) AVERAGE FORWARD CURRENT AMPERES 10 Ror L-Load 2 C-Load 1 0 0 25 50 75 100 125 150 TJ=150 1 TJ=25 0.1 Typ.values 0.01 0.001 175 LEAD TEMPERATURE ( ) 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 INSTANTANEOUS FORWARD VOLTAGE (VOLTS) FIG.3-MAXIMUM NON-REPETITIVE FORWARD SURGE CURRENT FIG.4-TYPICAL THERMAL RESISTANCE 1000 50 R0JA THERMAL RESISTANCE JUNCTION AMBIENT(/W) IFM 400 Permissible surge current(A) 1 Cycle 200 TJ=25 100 40 40 Max 30 20 Typ 10 20 1 2 4 10 20 NUMBER OF CYCLES AT 50Hz L L 20 25 100 0 0 5 10 15 L, LEAD LENGTH (mm) 30