Microsemi Corp. Bipolar Transistors - BJT 2N4957UB/TR

The 2N4957UB/TR is a surface-mount PNP silicon transistor qualified to MIL-PRF-19500/426 for high-reliability VHF-UHF amplifier, oscillator, and mixer applications. It is packaged in a ceramic 4-lead surface-mount case measuring 0.128 inches in length, 0.108 inches in width, and 0.056 inches in height, with gold-plated terminals and a weight under 0.04 grams. Maximum ratings include a collector-emitter voltage of -30 V, a total power dissipation of 200 mW at 25 °C, and a junction temperature range of -65 °C to +200 °C. Electrical characteristics include a forward current gain (hFE) of 15 to 165 at -5 mA collector current, a common emitter small-signal current gain magnitude of 12 to 36 at 100 MHz, and a noise figure of 3.5 dB at 450 MHz with 50 Ω source resistance. The device is RoHS compliant and meets JANTXV, JANTX, and JAN reliability levels.