OBSOLETE

LM2476

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SNOSAH7B – JANUARY 2004 – REVISED APRIL 2013

THEORY OF OPERATION

The LM2476 is a high voltage monolithic three channel CRT driver and triple bias clamp suitable for low-cost

color monitor applications. The LM2476 operates with 85V and 8V power supplies. The part is housed in the 19-

lead TO-220 molded plastic power package. The pinout and internal connection diagram is shown in .

The CRT Driver circuit diagram is shown in . The PNP emitter follower, Q5, provides input buffering. Q1 and Q2

form a fixed gain cascode amplifier with resistors R1 and R2 setting the gain at

−27. Emitter followers Q3 and Q4

isolate the high output impedance of the cascode stage from the capacitance of the CRT cathode which

decreases the sensitivity of the device to load capacitance. Q6 provides biasing to the output emitter follower

stage to reduce crossover distortion at low signal levels. The typical driver DC transfer function is shown in

Figure 4.

DC transfer function is shown in Figure 5.

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