Central Semiconductor Corp. Bipolar RF Transistors CM4957 PBFREE

The CM4957 is a PNP silicon RF transistor in a TO-72 hermetically sealed package, designed for high-frequency amplifier and non-saturated switching applications. It has a collector-base voltage rating of 30 V, collector-emitter voltage of 25 V, and continuous collector current of 30 mA. Power dissipation is 200 mW at TA=25°C and 300 mW at TC=25°C. The transistor offers a transition frequency (fT) of 1200 to 2500 MHz at VCE=10 V and IC=2.0 mA, with current gain (hFE) ranging from 20 to 150 under the same conditions. The TO-72 case has a body diameter of 5.31 to 5.84 mm and a length of 12.70 mm. The lead configuration identifies pin 1 as emitter, pin 2 as base, pin 3 as collector, and pin 4 as case. The PBFREE suffix indicates a lead-free plating variant, consistent with the series' optional plating configurations.