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OC45 Transistor Data

Key transistor data for the OC45 PNP IF germanium transistor including key electrical parameters, pinout, package type and many other key transistor datasheet details.

The OC45 was a PNP germanium transistor used for IF applications with an fT of 4 MHz. Whereas the OC44 was looked upon as being a higher frequency, RF transistor the OC45 did not have such a high fT and was generally used for IF applications.

In view of its fT, the OC45 was used in IF amplifiers with IFs of around 455 kHz where its lower fT was more than acceptable.

The OC45 still came in the same black pained glass envelope as other transistors from Philips / Mullard of the time.

Key datasheet details and performance parameters for the OC44 transistor.

OC44 transistor datasheet parameters & data
Parameters	Details
Transistor type	PNP germanium IF transistor
Package type	X02
V_CBO max (V)	-15
V_CEO max (V)	-15
V_EBOmax (V)	-12
I_C max (mA)	10
T_J Max °C	80
P_TOT mW	83
f_T min (MHz)	5
C_OB	12
h_fe	50 min
I_C for h_fe	1 mA
Similar / equivalents

Outline:

Pinout:

Explanation of transistor parameters

Parameter	Explanation
V_CBO Max	Maximum collector-base voltage with emitter open circuit .
V_CEO Max	Maximum collector-emitter voltage with base open circuit.
V_EBO Max	Maximum emitter-base voltage with collector open circuit.
V_CEsat (included where applicable)	The voltage drop across the collector-emitter when the transistor is fully saturated (acting as a closed switch).
I_C Max	Maximum collector current.

Parameter	Explanation
T_J	Maximum junction temperature.
P_TOT Max	Maximum device dissipation normally in free air at 25°C unless other conditions indicated.
f_T Min	Minimum cutoff frequency at which the current gain in a common emitter circuit falls to unity.
C_OB Max	Maximum collector capacitane, normally measured with emitter open circuit.
h_FE	DC current gain for H_FE at I_C. [Note hfe is the small signal gain and although this may be slightly different, the transistor current gain will vary considerably from ne transistor to the next of the same type.]
P_TOT Max	Maximum device dissipation normally in free air at 25°C unless other conditions indicated.

These are the main transistor parameters that have been included in our list. There are others, but these help quantify the main elements of the performance of the transistor.

Read more about . . . . Transistor Data-sheet Specifications & Parameters.

Please note, that the data given is the best estimate we can give within a tabulated summary of this nature. Parameters also vary between manufacturers. Electronics Notes cannot accept any responsibility for errors, inaccuracies, etc, although we do endevaour to ensure the data is as accurate as possible.

Notes and supplementary information

The OC45 was the recognised IF transistor from Philips / Mullard in the late 1950s and early 1960s.

It was used in many small transistor radios of the day, usually in the IF amplifier section in a superheterodyne radio.

It is assumed that it was manufactured on the same die as the OC44, and then the higher fT and higher gain transistors were selected to be labelled as an OC44, and the others as OC45. This was reflected in the proce as the OC45s were normally much cheaper.