4N25, 4N26, 4N27, 4N28 Vishay Semiconductors Optocoupler, Phototransistor Output, with Base Connection 1.5 FE Normalized to: V = 5 V CC V = 10 V, I = 20 µA CE b 50 °C 70 °C T = 25 °C A 1.0 f = 10 kHz RL DF = 50 % 25 °C V - 20 °C O 0.5 I = 10 mA F V = 0.4 V - Normalized Saturated h CE FE(sat) 0.0 Nh 1 10 100 1000 i4n25_14 i4n25_11 Ib - Base Current (µA) Fig. 11 - Normalized hFE vs. Base Current and Temperature Fig. 14 - Switching Schematic 1000 2.5 I = 10 mA, T = 25 °C F A V = 5.0 V, V = 1.5 V CC th tPHL 100 2.0 10 1.5 - Propagation Delay (µs) tPLH - Propagation Delay (µs) t PLH t PHL 1 1.0 0.1 1 10 100 i4n25_12 R - Collector Load Resistor (kΩ) L Fig. 12 - Propagation Delay vs. Collector Load Resistor IF tD V tR O tPLH V = 1.5 V TH t t t PHL S F i4n25_13 Fig. 13 - Switching Timing www.vishay.com For technical questions, contact: optocoupleranswers@vishay.com Document Number: 83725 136 Rev. 1.8, 07-Jan-10